The Universe Wreckers

A Tale of Neptune

By Edmond Hamilton

Author of "Locked Worlds," "The Other Side of the Moon," etc.

Illustrated by WESSO

It is problematical whether the enormous distance that lies between the Earth and Neptune is the only reason why so much on that planet remains a mystery to astronomers. If the great sphere were not so remote, much might be revealed to us. What might have happened to some of the other planets, perhaps so much older than the Earth, and what might be found upon them, might easily exceed the pale of human conception. But that is exactly why the subject of the possibilities of life 2000 millions of miles away from us, opens such a fertile field for writers of scientific fiction. And there is no assurance that the sun, for instance, should continue indefinitely to turn at its present speed. What might happen if it should, for some reason, begin rotating at an increasing frequency? Mr. Hamilton, who needs no introduction to readers of Amazing Stories and certainly needs no further commendatory note, concerns himself chiefly with the trip to Neptune and "life" on Neptune. "The Universe Wreckers" is certainly the best interplanetary story by this author that we have published thus far.

[Transcriber's Note: This etext was produced from
Amazing Stories May, June, July 1930.
Extensive research did not uncover any evidence that
the U.S. copyright on this publication was renewed.]

CHAPTER I

A Warning of Doom

It was on the third day of May, 1994, that the world received its first news of the strange behavior of the sun. That first news was contained in a brief message sent out from the North American Observatory, in upper New York, and signed by Dr. Herbert Marlin, the observatory's head. It stated that within the last twenty-four hours a slight increase had been detected in the sun's rotatory speed, or rate of spin, and that while that increase might only be an apparent one, it was being further studied. That brief first message was broadcast, a few hours later, from the Intelligence Bureau of the World Government, in New York. It was I, Walter Hunt, who supervised the broadcasting of that message at the Intelligence Bureau, and I remember that it seemed to me of so little general interest that I ordered it sent out on the scientific-news wave rather than on the general-news wave.

Late on the next day, however—the 4th—there came another report from the North American Observatory in which Dr. Marlin stated that he and his first assistant, an astronomical student named Randall, had checked their observations in the intervening hours and had found that there was in reality a measurable increase in the sun's rotatory speed, an increase somewhat greater than had been estimated at first. Dr. Marlin added that all the facilities of the observatory were being utilized in an effort to determine the exact amount of that increase, and although it seemed at first glance rather incomprehensible, all available data concerning it would be gathered. And at the same hour, almost, there came corroborative reports from the Paris and Honolulu Observatories, stating that Dr. Marlin's first observations had already been confirmed independently by their own observers. There could be no doubt, therefore, that the sun was spinning faster!

To astronomers this news of the sun's increased rotatory speed became at once a sensation of the first importance, and in the hours following the broadcasting of Dr. Marlin's first statement, we at the Intelligence Bureau had been bombarded with inquiries from the world's observatories regarding it. We could only answer those inquiries by repeating the statement already sent out on the scientific-news wave and by promising to broadcast any further developments instantly from our Bureau, the clearing-house of the world's news. This satisfied the scientifically-minded, while the great mass of the public was so little interested in this slight increase in the sun's rate of spin as not to bother us with any questions concerning it. I know that I would have taken small interest in the thing myself, had it not been for a personal factor connected with it.

"Marlin!" I had exclaimed, when the Intelligence Chief had handed to me that first report for broadcasting. "Dr. Herbert Marlin—why, he was my astronomy prof up at North American University, two years ago."

"Oh, you know him," the Chief had remarked. "I suppose then that this statement of his on the sun's increased rate of spin is authentic?"

"Absolutely, if Dr. Marlin gave it," I told him. "He's one of the three greatest living astronomers, you know. I became good friends with him at the University, but haven't seen him for some time."

So that it was with an interest rather unusual for me, that I followed the reports on this technical astronomical sensation in the next few days. Those reports were coming fast now from all the observatories of Earth, from Geneva and Everest and Tokio and Mexico City, for almost all astronomers had turned their interest at once toward this unprecedented phenomenon of the sun's increased rate of spin, which Dr. Marlin had been first to discover. The exact amount of that increase, I gathered, was still somewhat in doubt. For not only did the sun turn comparatively slowly, but the problem was complicated by the fact that it did not, like the Earth or like any solid body, rotate everywhere at the same speed, but turned faster at the equator than at its poles, due to its huge size and the lack of solidity of its mass. Dr. Marlin, however, stated that according to his observations the sun's great fiery ball, which had rotated previously at its equator at the rate of one rotation each 25 days, had already increased its rate of spin, so as to be turning now at the rate of one rotation each 24 days, 12 hours.

This meant that the sun's rotatory period, or day, had decreased 12 hours in three Earth-days, and such an unprecedented happening was bound to create an uproar of excitement among astronomers. For to them, as to all, who had any conception of the unvarying accuracy and superhuman perfection of the movements of the sun and its worlds, such a sudden increase of speed was all but incredible. And when on the fourth day Dr. Marlin and a score of other observers reported that the sun's rotatory period had decreased by another 4 hours, the excitement of the astronomers was unprecedented. A few of them, indeed, sought even in the face of the recorded observations to cast doubt on the thing. The sun's rotatory speed, they contended, could be measured only by means of the sun-spots upon its turning surface, and it was well known that those sun-spots themselves often changed position, so that this sudden increase in speed might only be an illusion.

This contention, however, found small support in the face of the indisputable evidence which Dr. Marlin and his fellow-astronomers had advanced in the shape of numerous helio-photographs and time-recordings. The sun was spinning faster, that was undoubted by the greater part of the world's astronomers—but what was making it do so? Was it due to some great dark body passing the solar system in space? Or was it due to strange changes within the sun's great fiery sphere? It was the latter theory, on the whole, that was favored by most astronomers, and which struck me at the time as the most plausible. It was generally held that a great shifting of the sun's inner layers, a movement of its mighty interior mass, had caused this sudden change in speed of rotation. Dr. Marlin himself, though, when questioned, would only state that the increased rate of spin was in itself beyond doubt but that no sound theory could as yet be formed as to the phenomenon's cause.

And while the astronomers thus pondered and disputed over the thing, it had begun to arouse repercussions of interest in the non-scientific public also. More and more inquiries concerning it were coming to us at the Intelligence Bureau in those first few days, those inquiries becoming so numerous as to cause us to switch the news on the thing from the scientific-news wave to the general-news wave, which reached every communication-plate in the world. It was, no doubt, out of sheer lack of other topics of interest that the world turned thus toward this astronomical sensation. For sensations of any kind were rare now in this peaceful world of ours. The last mighty air war of 1972, which had ended in the total abolition of all national boundaries and the establishment of the World Government with its headquarters in the new world-capital of New York, had brought peace to the world, but it had also brought some measure of monotony. So that even such a slight break in the order of things as this increase in the sun's rate of spin, was rather welcomed by the peoples of the world.

And now, the thing had passed from the realm of the merely surprising to that of the astounding. For upon the fifth and sixth days had come reports from Dr. Marlin and from the heads of the other observatories of the world that the strange phenomenon was still continuing, that the sun's rotatory speed was still increasing. In each of those two days, it was stated, it had decreased its period of rotation by another 4 hours, the same daily decrease noted previously. And the exactness of this decrease daily, the smoothness of this strange acceleration of the sun's spin, proved that the acceleration could not have been caused by interior disturbances, as had at first been surmised. A great interior disturbance of the sun might indeed cause it to spin suddenly faster, but no such disturbance could be imagined as causing an exact and equal increase in its speed of spin with each succeeding day. What, then, could be the cause? Could it be that in some strange way the universe was suddenly running down?

But while Dr. Marlin and his fellow-astronomers discussed this matter of the phenomenon's cause, it was its effects that had begun to claim the attention of the world at large. For that increase of the sun's speed was already making itself felt upon Earth. Even the great storms in the sun's mass, those storms that we call sun-spots, indeed, make themselves felt upon Earth by the intense electrical and magnetic currents of force which they throw forth, causing on Earth electrical storms and auroras and strange weather-changes. And now all the usual phenomena were occurring, but enhanced in intensity. On the third day of the thing, the 6th of May, there occurred over the mid-Atlantic an electrical storm of such terrific power as to all but sweep from the air the great air-liners caught in it, the Constantinople-New York liner and a grain-ship bound from Odessa to Baltimore having been forced down almost to the sea's surface by the terrific air-currents. Great auroras were reported farther south than ever before, and over all our Earth changes in temperature were quick and sudden. And among the other new phenomena called into being, apparently by the sun's increased spin, were the new vibrations discovered at that time by Dr. Robert Whitely, a prominent physicist and a colleague of Dr. Marlin's at North American University.

Dr. Whitely's report, though rather obscured in interest by the central fact of the sun's increased speed of spin, was yet interesting enough to physical students, for in it he claimed to have discovered the existence of a new and unknown vibratory force, emanating apparently from the disturbed sun. This was, he claimed, a vibration whose frequency lay in the octaves between light and Hertzian or radio vibrations, an unexplored territory in the domain of etheric vibrations. Dr. Whitely himself had for some time been endeavoring to push his researches into that particular territory, but though he had striven with many methods, he had been able to produce or find no etheric vibrations of that frequency until the strange increase of the sun's rotatory speed had begun. Then, he stated, his instruments had recorded new vibrations somewhere out in space toward the sun, whose frequency lay between the light and Hertzian frequencies, and which seemed a force-vibration of some sort, weak reflections from it only being recorded by his instruments. It seemed possible, he stated, that this strange new force-vibration was being generated somewhere inside the disturbed sun itself, and he was studying it further to determine the truth of this theory.

This discovery of Dr. Whitely's, however, interesting though it was, seemed to be but a side-issue of the real problem, the acceleration of the sun's rotation. After the sixth day, there were no further reports from Dr. Marlin and his fellow-astronomers. During all the seventh and eighth and ninth days there came no word to the Intelligence Bureau regarding it, from any of the astronomers who had formerly reported to us on it. And though we got into touch with Dr. Marlin and the others by communication-plate, none of them in those three days would make any statement whatever on the thing, saying only that it was being carefully studied by them and that a statement would be issued soon. It was evident from this universal sudden silence on their part that the astronomers of the world's observatories were acting in conjunction, but why they should want to withhold from an interested world the news on this strange acceleration of the sun's spin, we could not understand. The great electrical storms and temperature-changes that had prevailed over Earth continued, and we were anxious to know how much longer we might expect them to continue.

"One would think that Dr. Marlin and the other astronomers had some great secret they were keeping from us," I remarked to Markham, the Intelligence Chief, and he shook his head.

"Secret or not, Hunt, they're doing us out of the first unusual news-subject we've had for a year," he said. "Why don't they give us whatever they've learned about this change in the sun's rate of spin?"

It was a question repeated by more than one in those days, for the great public having become interested in the matter was irritated by this silence on the part of Dr. Marlin and his fellow-scientists. Whatever they had learned or guessed as to the thing's cause, why did they not give their information to the Intelligence Bureau for distribution to the world? It was hinted freely that the whole matter was a hoax devised by Dr. Marlin, which had duped the astronomical world for the time being, and which they were reluctant to acknowledge. It was suggested also that the World President or the World Congress should take action to make the astronomers give out their usual reports. The public was quickly working itself into a state of indignation over the matter, when there suddenly burst upon it that doom-laden and terrible statement by Dr. Marlin, which was to loose an unprecedented terror upon the peoples of Earth.

It was on May 13th, the tenth day after Dr. Marlin's first announcement of the thing, that he gave to the world through the Intelligence Bureau that epochal statement, and in it he referred first to his silence and to the silence of his fellow-astronomers in the preceding few days. "In those days," he said, "every observatory in the world has been engaged in an intensive investigation of this acceleration of the sun's rotation, which I discovered. And in each of those days the sun's rotatory speed has continued to increase at exactly the same rate! In each day that speed has increased so much as to cut down the sun's rotatory period 4 hours more, so that now, ten days after the beginning of the thing, its rotatory period has been cut down by 40 hours. In other words, ten days ago the sun turned as it had always turned to our knowledge, at the rate of one turn in every 25 days, at its equator. Now the sun's rotatory speed has increased to the rate of one turn in every 23 days, 8 hours.

"And that increase of rotatory speed continues. With each passing day the sun's rate of rotation is growing greater by the same amount, with each passing day it is lessening its rotatory period by 4 hours. And that steady increase of rotation of the sun, if it continues, spells destruction for the sun as we know it! All know that the sun in rotating generates in its own mass a certain amount of centrifugal force, force which tends to break up its mass. That force is not large enough, however, in our own sun to affect its great mass, since our sun's speed of rotation is not great. We know that over vast periods of time a sun's rotatory speed will increase, due to the slow shrinkage of its mass, and that when the speed has increased to a point where its centrifugal force is greater than its own power of cohesion, the sun breaks up like a bursting flywheel, breaks up or divides into a double or multiple star. Thousands upon tens of thousands of the stars of our universe are double or multiple stars, having been formed thus from dividing single suns, whose speed or rotation became too great.

"But as I have said, our own sun seemed in no danger of this fate, since the natural increase of a sun's rotatory speed, due to the shrinkage of its mass, is so unthinkably slow, requires such unthinkable ages, that it is out of all concern of ours. For our sun has rotated once in 25 days at its equator, and it has been calculated that it would need to reach a rotatory speed of once in one hour before its centrifugal force would be great enough to divide it, to break it up. And because of that eon-long slowness of a star's natural increase of rotatory speed, there seemed, indeed, no slightest peril of our own sun dividing or breaking up thus, because before it could reach that speed of rotation required, unthinkable ages must elapse.

"But now, due to some cause, which none of us have been able to guess, some great cause utterly enigmatic and unknown to us, our sun's rotatory speed has begun suddenly to grow greater, to increase! Faster and faster every day the sun is spinning, its speed of rotation increasing by the same amount each day, its rotatory period decreasing by exactly 4 hours each day! You see what that means? It means that if the sun's speed of spin continues to increase at that steady rate, if its rotatory period continues to decrease by that amount each day, as it shows every sign of doing, within 140 days more the sun's rate of rotation will have increased so much that it will be turning at the rate of one turn in one hour, will have reached that speed at which our calculations show that its great mass can no longer hold together! So that 140 days from now, if this increase of rotatory speed continues, our sun will infallibly divide into a double star!

"And that division means death for Earth and almost all its sister-planets! For when the sun divides into two great new suns, the first force of their division will send those two mighty balls of fire apart from each other, and pushing thus apart from each other, they will inevitably engulf in their fiery masses all the inner planets and most of the outer ones! Mercury, Venus, Earth and Mars will undoubtedly be engulfed in the fires of the two dividing suns upon their first separation, their first division. Jupiter and Saturn and very probably Uranus will be drawn inevitably into fiery death also in one or another of those great suns, if they too are not overwhelmed in the first separation. Neptune alone, the outermost of all the sun's planets, will be far enough out to escape annihilation in the dividing suns when the terrific cataclysm occurs. For if the sun continues to spin faster, as it is now doing, that cataclysm must inevitably occur, and must as inevitably plunge our Earth to fiery doom and wreck our solar system, our universe!"

CHAPTER II

To Neptune!

"Doom faces us, a fiery doom in which the dividing sun will annihilate Earth and most of its sister-planets! Panic even now grips all the peoples of Earth, such panic as has never been known before, as that doom marches inevitably toward them! Yet inevitable, inescapable as that doom seems, we of the World Congress, we who represent here all the gathered peoples of Earth, must endeavor to find even now some last chance of lifting this awful menace from us!"

The World President paused, his dark, steady eyes searching out through the great room at whose end, upon a raised platform, he stood. Behind him on that platform sat a row of some two-score men and women, garbed like himself and all others in the modern short and sleeveless garments of differing colors, while before him in the great room stretched the rows of seated members of the great World Congress, the twelve hundred men and women who represented in it all the peoples of Earth. Just beneath the great platform's edge sat Markham, the Intelligence Chief, and myself; before us were the switches that controlled the communication-plates throughout the room that broadcast all proceedings in it to the world. And sitting there, I could glance up and see among those two-score behind the World President two figures well known to me; the strong figure of Dr. Marlin, with his intense gray eyes and gray-touched hair; and the lounging, dark-haired form of Dr. Robert Whitely, his somewhat sardonic countenance and cool eyes turned now with keen interest toward the World President before him. And as the latter began again to speak my own gaze shifted toward him.

"It has been just three days," the World President was saying, "since Dr. Herbert Marlin and his fellow-astronomers gave to the world a warning of this doom that hangs above it, gave to us a warning that in less than five months more, if the sun's rotatory speed continues to increase, it must inevitably divide into a double star and in so doing wreck our universe and plunge most of its planets into fiery death. I need not speak now of the terror that has reigned over Earth since that announcement. It is sufficient to say that the first wild riots, inspired by that terror in Europe and Northern Asia, have been suppressed by the dispatch of police cruisers, and that throughout the world order is being maintained and most of our world's activities are being carried on as usual. Yet it is clear to all that the panic which that statement inspired has not subsided, rather it is growing in force over the Earth's surface with the passing of each day. For each day is bringing our Earth nearer to death!

"For each day, each of these three intervening days, the sun's speed of rotation has continued to increase by the same exact amount! Each day its rotatory period has decreased by 4 hours more! It cannot be doubted then that whatever is causing this strange acceleration, it will keep on, until in a mere 137 days from the present, the sun's rotatory period will have reached the figure of one hour. When that occurs our sun will, as Dr. Marlin has warned us, divide into a double star! Nothing in the universe can save our Earth or its neighboring planets then. Our one hope, therefore, to save ourselves, is to prevent that thing from happening, to halt this acceleration of the sun's spin before it reaches its critical point 137 days from now! For it is only by halting that steady increase of its rotatory speed that we can avoid this terrific cataclysm that means death for us!

"But can we halt this acceleration of the sun's spin when none of our astronomers has been able to ascertain its cause? That is what you will ask, and in answer to that I say, some hours ago two of our scientists did ascertain that cause. They learned at last what great, what almost incredible cause is responsible for this acceleration of our sun's rotatory speed. Those two scientists are well known to all of you, for they are Dr. Herbert Marlin himself, who first discovered the fact of the sun's faster spin, and Dr. Robert Whitely, his physicist-colleague, who has been studying the new vibrations recorded by his instruments since the beginning of that acceleration of the sun's rotatory speed. These two men have found, at last, the terrible cause of our sun's strange behavior, and it is that you might hear it that I have called you of the World Congress together at this time. It is Dr. Marlin himself, then, who will tell you what he and his fellow-scientist have discovered."

The World President stepped aside, and as he did so Dr. Marlin rose, stepped forward to the great platform's edge, and looked quietly out over the great room's occupants. I was aware as he did so of a quality of utter tension in all the hundreds in that room, of a hushed silence, in which the slightest sound seemed unnaturally loud. Through the great windows there came a deep hum of sound from the sunlit surrounding city, but in the big room itself was silence almost complete until Dr. Marlin's strong, deep voice broke it.

"It was thirteen days ago," he said, "that the acceleration of our sun's rotatory speed was first noted, thirteen days ago that it first began to spin faster. In those days we of the world's observatories have sought unceasingly for the cause, whatever it was, that was behind this strange acceleration of the sun's spin, and have sought for that cause even more intently in the last few days, since it was recognized by us, that this increasing rotatory speed foreshadowed the division of the sun and the doom of almost all its planets. That acceleration of speed was too exact, too uniform each day, to be the result of interior disturbances. It could not be the result of the influence of some dark body passing the solar system in space, for such a body would affect the planets also. What, then, could be the thing's cause? That is what I and all astronomers have been seeking to solve in the last days. That great enigma has finally been solved, not by an astronomer, but by a physicist—by Dr. Robert Whitely, my fellow-professor at North American University.

"It will be remembered that when the first great effects of the sun's increased spin became apparent on Earth, the great electrical storms and temperature-changes that still are troubling Earth, Dr. Whitely announced the discovery of new vibrations which were apparently emanating from the troubled sun also. That new vibration lay in frequency between the Hertzian and the light vibrations, an unexplored territory in the field of etheric vibrations. It seemed, Dr. Whitely then stated, a force-vibration of some sort, the weak reflected impulses from it, that reached his instruments, affecting them as tangible force. It seemed reasonable to suppose, therefore, that this new force-vibration or ray was being generated inside the sun's disturbed mass, just as light vibrations and heat vibrations and cosmic-ray vibrations and many others are generated by and radiated from the sun.

"In the next days, however, Dr. Whitely continued to study this new vibration, and endeavored to trace it accurately to the sun by using recording instruments which recorded it as strongest or weakest in various quarters of space. By means of these instruments, he was able to plot the course of this force-vibration or ray in space, to chart the path of its strongest portion in space. And by doing this he found that this new force-vibration, contrary to his expectations, was not being radiated out equally in all directions as one might expect. It was being shot forth in a great force-beam or ray, one which cut a straight path across half our solar system! And that mighty force-ray, whose weaker reflected pulsings only struck his instruments here on Earth, was not being generated and shot forth by the sun, but was striking the sun! And tracing its path out across the solar system by his charts he found that the great force-ray was being shot out from the planet Neptune, was stabbing across the great gulf from Neptune, the outermost planet, and striking the sun!

"And it was that giant force-ray, as Dr. Whitely and I soon saw, that was and is making our sun's rotatory speed steadily increase! For that great ray, as we found, is one that can stab across space and strike any object with terrific force, as though it were solid and material! You know that even light rays, light vibrations, exert a definite pressure or force upon the matter which they strike. Well, these force-vibrations, of greater wavelength than the light vibrations, also exert pressure and force upon any matter which they strike, but they exert an infinitely greater pressure, can stab across the vast void and strike any object with colossal and unceasing pressure. In this way, then, this great force-vibration or ray hurtles across space and strikes all matter in its path with terrific force, as though a solid arm were pushing across the gulf.

"And this terrific ray of force, stabbing in through the solar system from Neptune, was striking our sun just at its edge, just at its limb, at its equator. It struck that edge turning always away from Neptune, and striking that turning edge of the sun with terrific force as it did, the great pushing ray made it turn even faster away from Neptune at that edge, made the sun turn faster and faster! Pressing always upon the turning sun's edge with the same great power, this mighty force-ray has made the sun rotate faster each day, has made its rotatory speed increase by the same amount each day. And since that great ray is still stabbing across the gulf from Neptune to the sun, is still accelerating the sun's spin, it is to that ray that we will owe the division of our sun into two parts, 137 days from now, and the consequent wrecking of our solar system!

"For Neptune alone will escape the cataclysm that will take place when the sun divides, and it is from Neptune, from intelligent beings on Neptune, there can be not the slightest doubt, that this great force-ray comes. For it cannot be doubted for an instant that this mighty force-ray is the work of intelligent creatures upon Neptune. Never in all the many discussions concerning the possibility of life on the other planets have astronomers conceded any possibility of life on Neptune, the outermost of the sun's worlds, for though we have always known it to have air and water, its great distance from the sun must needs make it so cold a world as to be unable to sustain life. That was our belief before, but now with this great ray from Neptune swiftly wrecking our solar system before our very eyes, we can no longer doubt that life, intelligent life, exists there!

"It is the beings of Neptune, therefore, the creatures of the sun's outermost world, who are making the sun spin faster and faster, who are deliberately planning to make our sun divide into a double star, to wreck its universe! What their reason is for doing this, we cannot now guess. We know that Neptune, almost alone among the sun's planets, will survive the great cataclysm of its division, and we can but hazard the thought that it is for some great advantage to themselves that the Neptunians are engaged upon this colossal task. Neither can we guess just how, exactly, they are doing it, how they are able to push against the sun with such colossal force without Neptune itself being pushed out into the void by the tremendous reaction from that push. But these things are not of the greatest interest to us now.

"The thing of greatest interest to us now is this: Can we halt this acceleration of the sun's rotation, can we thwart the doom which the Neptunians would loose upon us? To do that there is but one remedy! That is to bring to an end this great force-ray which the beings of Neptune are playing upon our sun's edge, with which they are making that sun turn faster. And to bring that ray to an end, to destroy it, it is necessary that we go out to Neptune, to the source of that great ray. For it is only at its source, whatever that source may be, that this force-ray can be destroyed! And it is only by destroying that force-ray that Earth and its sister-planets can be saved!

"This proposition, this plan to go out to Neptune itself, may seem to you impossible. For greatly as our scientific knowledge has risen in the last decades, we have been unable to bridge the gulf to even the nearest of the planets. True, we have managed to send rockets to our moon and explode flares there by means of them, but never yet have any of us reached even the nearest of our neighboring planets. And thus to propose to go out to Neptune, the farthest and outermost of all the planets, the last outpost of our solar system, may appear to you quite senseless. But it is not so, for now, at last, there is given to us the power to venture out into the gulf of space to other planets! And that power is given to us by the very doom that now threatens us, since it is the force-ray or vibration with which the beings of Neptune are turning our sun faster, which we can use to cross the gulf of space!

"For since his instruments first received and recorded that vibration, the weak reflected pulsings of the great ray, Dr. Whitely has studied it intensively, and has been able, by reversing the hook-up of his receiving and recording instruments, to produce similar vibrations, a similar ray, himself! He has been able to devise small generators which produce the same force-ray, and on that principle larger generators also can be devised and constructed, to shoot forth a force-ray of immense power. With such a force-ray, generated from inside a strong, hermetically-closed flier, one could shoot out at will into the great void! For if such a flier, resting on Earth, turned its powerful ray down upon Earth, that ray would strike Earth with terrific force. Being so vast in mass, and the flier from which the ray is shot down being so small, it would not be Earth that would be perceptibly moved by the ray, but the flier itself would be shot instantly up and outward into space by the ray's great pushing reaction!

"It would be necessary only to head the space-flier out toward the desired planet upon starting, and the pushing force of the great ray, constantly turned on, would so accelerate the flier's speed that it would be pushed out toward that planet at a terrific velocity, a speed which could be controlled by the power of the pushing ray. To escape the attraction of other planets among which it might pass, the space-flier would need only to shoot a similar great force-ray out toward whatever planet was attracting it, and the pushing force of that ray would hold the flier out from it. And when the space-flier neared the planet that was its goal, it could gradually slow its progress by means of a ray shot ahead toward that planet, braking its forward rush thus, and being able to land smoothly and without harm upon that planet!

"Such a space-flier as that might be built and operated in that way, with the great force-ray or vibration of the beings of Neptune to propel it, and in such a flier it would be possible to go out across the gulf to Neptune itself! Such a flier, pushing itself out into space with a great ray, could be brought to such colossal speeds that the journey out through the gulf to the distant planet could be accomplished in but a score or more of days. We have the power to build that flier, we have at last, at this tense moment, the power to send such a space-flier out into the void. And I propose that such a space-flier be built with the greatest speed possible and be sent out to Neptune to locate and if possible to destroy the source of the mighty force-ray whose colossal power is spinning our sun ever faster, threatening Earth and most of its sister-planets with a final doom!

"A single space-flier capable of holding three or four men and their equipment and supplies, could be built in a month or more, if all energies were concentrated upon it, and if the great generators of the force-ray which it would need could be constructed in that time. That single flier, when built, should be sent out to Neptune at once! For little enough time remains to us before the break-up of our sun; little more than four months indeed. And that single flier, going out with its occupants at once, could locate the source of the mighty force-ray on Neptune, and if it could not destroy that ray's source, could at least return to Earth with exact knowledge of its position. And in the interval, there could be constructed here on Earth a fleet of such space-fliers, so that with a knowledge of the great ray's source these might be able to destroy it. All depends, however, upon constructing and sending out that first space-flier, while there is yet time!

"It would not be possible to construct a large space-flier in the short time of a month that I have mentioned, but a small one capable of holding four men, say, could be built in that time if all efforts were concentrated upon it. And I myself will be one of those four! For upon disclosing this plan to the World President, I was asked by him to be the commander of such a space-flier on its venture out to Neptune; and I accepted! Another of that four must be Dr. Whitely, whose discovery of the great force-ray from Neptune has shown us whence our doom is coming, and which discovery has alone made such a space-flier possible. It is my intention to take as a third my own assistant, Allen Randall, and as the fourth person to make this momentous voyage it would be best, no doubt, to have some younger member of the Intelligence Bureau, so that a complete report on the great ray's source and on all else encountered could be brought back, in case we were unable to destroy the ray ourselves.

"This, then, is the one chance for our Earth, that in such a space-flier or fliers we of Earth can go out to Neptune and put an end to that mighty force-ray from Neptune that is spinning our sun ever faster. For if we can do that, if we can construct such a space-flier or fliers and reach Neptune and bring an end to that ray before the 137 days left to us have elapsed, we will have halted this acceleration of our sun's spin, will have prevented its division. But if we cannot do that, if we are unable in the short time remaining to us to accomplish the task of destroying that mighty force-ray, then the beings of Neptune will have accomplished their colossal purpose, will have caused our sun to divide into a double star and will have sent all its planets except Neptune to a fiery doom!"

Dr. Marlin's strong voice ceased, and as it did so an utter silence reigned over the great room for some moments, broken at last by the voices of the twelve hundred members of the great World Congress—breaking into a vast, indistinguishable roar! My heart was pounding at what I had heard, and I turned, spoke swiftly to Markham beside me, and then as he nodded was leaping up myself upon the great platform! Was leaping up to where Marlin was standing now with Dr. Whitely and the World President, the whole great room trembling now with the cheering shouts with which those in it greeted Dr. Marlin's announcement. And there I was speaking rapidly to the World President, and to Dr. Marlin.

"The fourth man, sir!" I cried. "The fourth man that's to go in the space-flier—let me be that fourth!"

The World President, recognizing me, turned inquiringly toward Dr. Marlin, who nodded, placing a hand on my shoulder. "Hunt is from the Intelligence Bureau," he said, "and he's young and has had scientific training—was one of my own students. We could have no better fourth."

My heart leaped at his words, and then the World President nodded to me. "You will be the fourth then, Mr. Hunt," he said, shaking my hand. And as I stood there on the platform with Marlin and Dr. Whitely, the World President was turning back to the hundreds of shouting members, a sea of faces extending back to the great room's walls. Cheering as they were at this last chance to save Earth and its peoples that had been proposed to them, this last hope given to them to halt the terrible doom overshadowing them, their great uproar yet stilled for a moment as the World President turned toward them, as his voice went out to them over the great room.

"You, the members of the World Congress," he said, "have heard that which Dr. Marlin has told you. With this last hope in view, it is unnecessary for me to tell you to bend now all the world's energies toward that one chance, toward the construction of the first space-flier. For since upon that space-flier rests the only chance to save Earth, to prevent the sun's cataclysmic division, which this great ray from Neptune is accomplishing, I have no fear but that in a month from now that space-flier will be completed. Have no fear but that in it, a month from now, Dr. Marlin and his three friends will start on their unprecedented and momentous voyage out from Earth into space; will start on their great flight out through the void—to Neptune!"

CHAPTER III

The Space-Flier Starts

"Three more days and the last work will be done—the space-flier will be finished!"

It was Dr. Marlin who spoke and Whitely beside him, nodded. "Three more days," he said, "and we'll be starting."

We four, Marlin and Whitely and Randall and myself, were standing on the flat roof of the great World Government building, that gigantic cylindrical white structure that looms two thousand feet into the air at the center of the new world-capital, New York. All around us there stretched the colossal panorama of New York's mighty cylindrical buildings, each rearing skyward from its little green park, extending as far away as the eye could reach, many of them rising on great supporting piers out of the waters of the rivers and bay around the island. In the late afternoon sunlight above them there swirled and seethed great masses of arriving and departing aircraft, unfolding their helicopter-vanes from their long hulls as they paused to rise or descend, seeming to fill the air, while away to the south the great Singapore-New York liner was slanting smoothly down toward the great flat surface of the air-docks. Yet it was to none of these things, nor to the masses of humans that swarmed and crowded in the city's streets far beneath us, that we four were giving our attention at that moment, for we were gazing intently at the great object that stood on the roof before us.

That object was a great gleaming metal polyhedron that loomed in a supporting framework beside us like a huge ball-like faceted crystal of metal. This great faceted ball of metal, though, was fully thirty feet in diameter, and here and there in the great, smooth, faceted, plane-surfaces of it were set hexagonal windows of clear glass, protected by thick raised rims of metal around them. There were also set in six of the facets six round openings a foot in diameter, one of these being in the faceted ball's top, one in its bottom, and four at equi-distant points around its equator. In one of the flat facet-sides, also, was a screw-door of a few feet diameter that now was open, giving a glimpse across a small vestibule-chamber inside through a second open screw-door into the great polyhedron's interior. That interior seemed crowded with gleaming mechanisms and equipment, attached to the inner side of the great metal shell.

Marlin was contemplating the great thing intently as we stood there on the roof beside its supporting framework. "Finished—in three more days," he repeated. "Everything's ready for the last generator."

"That will be done in two days more," said Randall, beside me. "Everything else at the World Government's laboratories has been suspended in order to get these generators ready for us."

"They've worked fast to get three of the generators in the flier already," Marlin acknowledged. "Especially since Whitely here, in directing them, had only his own first crude models to work on."

"Lucky we are to get the generators completed and the space-flier finished in the month we estimated!" I exclaimed. "If the whole world hadn't centered its energies on the space-flier's completion we'd never have done it—and even so it's been a tremendous task."

It had, indeed, been a period of tense and toiling activity for Marlin and Whitely and Randall and me, that time of four weeks that had elapsed since Marlin had proposed his great plan to the World Congress. In those weeks all our efforts, and all the efforts of the world too, it seemed, had been concentrated upon the building of that space-flier in which we four, first of all men, were to venture out into the great void, to flash out to Neptune in our attempt to halt the great ray that was spinning our sun ever faster to its destruction and to ours. For each day of those four weeks the rotatory speed of the sun had grown ever greater, its rotatory period decreasing by an exact four hours each day. The instruments of Dr. Whitely, too, showed that the mighty force-ray was still playing unceasingly from Neptune upon the turning sun's edge, spinning that sun ever faster. Already the terrific pressure of that great ray had lowered the sun's rotatory period to 18 days, 4 hours, and in hardly more than a hundred days more, we knew, would have brought the sun's rotatory period down to that critical figure of one hour at which it could no longer hold together, at which it would divide into a double star and plunge Earth to doom and wreck the solar system.

And with that knowledge, all the world had sought to aid in the construction of our space-flier. Dr. Marlin had directed that construction, aided by his assistant, young Randall, whom I had met for the first time and had found a sunny-haired fun-loving fellow of my own age. And it had been Dr. Marlin who, after consultation with the world's greatest engineering authorities, had chosen for the flier the form of a great polyhedron. Such a form, it had been found, could resist pressure from within and without much better than the spherical form that had been at first suggested, and it was realized that this power of resistance would be necessary. For upon venturing out from Earth's gravitation-field into gravitationless space, the very interior stresses of such a space-flier would tend to explode it unless it was braced against those stresses. Also the space-flier was to be shot out through the void and maneuvered in that void by the pushing reaction of its own great force-rays against the Earth or other planets, and though that force would thus hurtle the flier out at terrific speed, it would also crumple the flier itself unless it were strong enough to withstand the force-ray's terrific pressure.

With the space-flier's form decided and the plans for it drafted, work upon it had begun at once. At the World President's suggestion, it was being set up on the great flat roof of the World Government building. From over all Earth had come the world's most brilliant engineers and scientists to aid in its construction, for the world lay still beneath the great shadowing wing of fear that had been cast over it, when the peoples of Earth had learned first of the doom that Neptune and its beings were loosing upon the solar system. So that though the world's first wild panic had subsided, it had been replaced by a waxing realization and dread that had made the peoples of Earth and their representatives offer to us their help in this plan of ours, which alone held out any chance, however slender, of escape from the annihilation that was nearing Earth. Laboring ceaselessly day and night therefore, in picked crews of workers that every few hours replaced each other, Dr. Marlin and Randall and myself and our eager workers had swiftly brought the great space-flier's metal shell into being.

That great crystal-like shell, at Dr. Marlin's suggestion, had been made double-walled, the space between the two walls being pumped to as complete a vacuum as possible so that vacuum might insulate the flier's interior from the tremendous differences in temperature that it would meet in space. For where the sun's heat-radiations struck the flier in space it would be warm, hot even, but those parts in shadow would be subjected to the absolute zero of empty space. Each of these thick double walls, in turn, was itself built up of alternate layers of finest steel and of non-metallic, asbestos-like insulating material, pressed and welded together by titanic forces into a single thickness. And the great faceted wall-sections of the flier, when in place, had been so welded and fused one to the other by the new molecular-diffusion fusing process, that the great ball-like faceted flier might have been and was, in fact, a single and seamless polyhedron, its strength enormous.

In one of the flier's facets was the round screw-door, admitting one through a small vestibule-chamber, and then through a second hermetically-sealing door into the flier's interior. In that interior, all the flier's mechanisms and equipment had been attached directly to the inner side of its great crystal-like ball, with hexagonal windows, made double and of thick unbreakable glass, here and there in the walls, between the mechanisms. Just inside one of those large windows, at what might be called the ball-like flier's front, were ranged on a black panel of several feet in length the space-flier's controls. The most central of these controls were six gleaming-handled levers which controlled the flier's great force-rays, shooting them forth from any one of the six ray-openings in its sides, to send the flier hurtling through space by reaction, or to use against asteroids or other objects as a great weapon. Supported from the wall in front of those levers was a metal chair that swung on pivots and on sliding pneumatic shock-absorbing tubes, a metal strap across it to hold its occupant in it. And the occupant of that chair, with the six force-ray controls before him, thus controlled the flier's flight through space, and could, if necessary, use its great rays as weapons.

To the left of those controls were the recording dials and switches of the four great generators. Those four gleaming cubical generators themselves were attached to the other side of the flier's hollow interior, along with the marvelously compact and powerful Newson-Canetti batteries. Operating from those batteries whose power-stores were almost exhaustless, the generators, when turned on, would generate the great force-vibrations which, of a wavelength higher than that of light vibrations, exerted a terrific pressure or force beside which the pressure of light was as nothing. These vibrations were carried by thick black cables running between the flier's double walls to the projecting-mechanisms inside the six ray-openings, and from those openings the great force-vibrations were released as great force-rays by the operator of the flier's six controls. These great force-rays, we had found, almost equalled the speed of light itself in the velocity with which they shot out from the flier's ray-openings.

In front of the generators' recording dials and switches was suspended a metal chair like that of the control-operator, while between those two was a third chair before which, on the control-panel, were ranged the instruments recording the space-flier's conditions of flight. There was a space-speed indicator, working by means of ether-drift, a set of dials that accurately recorded the gravitational pull of celestial bodies in all directions, inside and outside temperature recorders, inside and outside air-testers, and beside others the controls of a number of the necessary mechanisms attached at different points inside the hollow faceted ball of the flier. Among these were the controls of the flier's air-renovator, which automatically removed the carbon-dioxide from the flier's breathed air by atomic dissociation and replaced it with oxygen from the compact tanks of compressed liquid-oxygen; the controls of the heating-mechanism, which beside its own heating coils was to utilize the heat of the sun on the flier's side in space; and the control of the hooded lights set above the flier's control-panel and mechanisms.

To the right of the control-operator's chair, too, there was a fourth similar chair before which were ranged on the control-panel a compact but extremely efficient battery of astronomical instruments. There was a ten-inch refracting telescope, its lens set directly in the big hexagonal window over the control-panel, the tube of the telescope, thanks to the new "re-reflecting" principle, being but a score or so of inches in length. There was also a small but efficient spectroscope similarly mounted, a micrometric apparatus for accurate measurements of celestial objects, and a shielded bolometer for ascertaining the radiated heat of any celestial body.

These four metal chairs, suspended there in front of the long control-panel and with the big hexagonal window before and above them, were mounted all upon special shock-absorbing tubes of pneumatic design which would enable us to withstand the pressure of our flier's acceleration upon starting, and the pressure also of its deceleration upon slowing and stopping. Seated in them, we would be able to look forth over the space-flier's controls into the void before us, and since gravitation would be lacking in the flier, once out in space, metal straps across them would hold us in them. Here and there among the mechanisms that lined the ball-like flier's interior, too, were hand-grips by which we could float without harm among the mechanisms and equipment, while the metal bunks attached at one point to the flier's interior were provided with metal straps to hold us in them during sleep.

Ranged among the mechanisms, that lined the flier's interior, were the cabinets that held our stores and special equipment. Among these were ample stores of food in thermos-cans, kept hot thus and obviating all necessity of cooking, the tanks of compressed water, and the extra liquid-oxygen tanks. Also attached to hooks on the walls were the four space-walkers that had been constructed for us to enable us to venture outside of the flier into airless space, if necessary. These space-walkers were cylindrical metal structures seven feet or more in height and three in diameter, tapering at the top to a smooth dome in which were small vision-windows. Each held a small generator of force-vibrations, and an equally small air-renovator. There were two hollow metal jointed arms that extended from the upper part, and on entering the cylinder and closing its base-door one thrust his own arms inside those hollow metal ones. They ended in great pincer-claws that could be actuated by one's own hands inside, while the space-walker itself was moved through the void by its generated force-vibrations being shot out from a small ray-opening in the cylinder's bottom.

Standing inside the hollow, ball-like polyhedron of the flier, therefore, its mechanisms and equipment extended all about and above and beneath one, attached rigidly in every case to the flier's inner surface. That equipment, those mechanisms, indeed, had taxed all the powers of the great World Government laboratories to provide in the short time that was ours, but by a miracle of effort it had been done. And now, as we four gazed up toward the great gleaming faceted thing, resting beside us there in its framework of metal girders, we knew that there remained only the last of the four great generators to be completed, and that in two days more, as Randall had said, that too would be completed and installed and the space-flier would be ready for its final tests and for the start of our great trip. Looking up at the great thing towering there beside us in the waning afternoon sunlight, I was struck with a sudden realization of the stupendousness of the task that we had set ourselves; of the thing that lay before us.

"To go out in that from Earth to Neptune—to Neptune!—it seems impossible," I said.

Marlin nodded, his hand on my shoulder. "It seems strange enough," he assented, "but to Neptune in three more days we're going, Hunt. For no other chance is there to save Earth from the doom marching upon it."

"But can we save it?" I exclaimed. "Can we four really hope to contend against beings who, whatever their nature, have power enough to reach across the solar system and speed our spinning sun on to its doom and ours?"

Marlin looked gravely at me, and at Whitely and Randall beside me. "A chance there is—must be," he said solemnly, "even though little time now remains to us. And with that chance—with Earth's chance—in our hands, we must strike out to the last with all our power for Earth!"

Those words of Marlin, I think, steadied us all in the whirling rush of activities that was ours during the next, the last, three days. For in those three days, as the last generator approached completion and was completed and installed, we four were ceaselessly busy with the last preparations for our start. Whitely, who had designed and was to have complete charge of the space-flier's great generators, was busy inspecting and testing those generators. Randall and I were familiarizing ourselves with the flier's controls, for we two were to alternate in controlling its flight through the void. Marlin, who would not only command our little party but would have charge of the astronomical equipment in it, and would chart our course out through the trackless gulf, was occupied beside numberless other tasks in plotting, with the assistance of some of the world's foremost astronomers, that course that we must follow now. So that as there came upon us the last day of June 16th, that day upon whose night we were to start our momentous journey, it found us working still upon our last preparations.

By the time that day and night had come, too, it found the excited expectation of the world keyed up to an agonized point. For days, indeed, great crowds had swirled about the base of the huge World Government building, on whose roof we worked, and, as the last hours approached, it seemed that all the world's thoughts, indeed, were concentrated upon that roof, upon the great gleaming space-flier on it. For all knew that upon that flier and upon the mission which we four were attempting in it depended the one chance of escape for Earth. For steadily, remorselessly, the sun was spinning still ever faster, the great pushing force-ray from Neptune still stabbing across the solar system to spin the sun on and on with greater and greater rotatory speed, until it divided and doomed Earth and its sister-planets. So that those last days, those last hours, seemed to all the world as to ourselves to pass with nerve-tearing slowness.

There came at last, however, the night of the 16th, the night of our start, with the space-flier complete and ready in its framework at last. The last work of Marlin and Whitely had been to check over the construction-plans of the flier, which were to be left behind so that a great fleet of space-fliers, as the World President had said, could be constructed. Were we to return from Neptune with knowledge of the position and nature of the great doom-ray's source there, that fleet of space-fliers would be ready to sally out and attempt to bring an end to the great ray. But that knowledge, if we gained it, we must bring back ourselves, since there was no method of communication from our space-flier to Earth, the well-known "Heaviside layer" surrounding Earth being impenetrable to all radio and communication vibrations and making such communication impossible. With this last preparation completed, however, we four stood ready upon the night of the 16th for the start of our great venture.

It was an hour after midnight that we were to start, and it was not until some minutes past midnight that Marlin and Whitely and Randall and I left our quarters in the World Government building and ascended to its roof. As we emerged upon that roof we stopped involuntarily. For the great roof itself and all the surrounding colossal city of New York were lit now with brilliant white suspended lights, and beneath them upon the roof and in the streets far beneath were masses upon masses of waiting men and women. Those upon the roof were the twelve hundred members of the great World Congress, assembled there to see our start out into the void on our desperate venture. At their center was a clear, roped-off space on the roof in which there towered the framework that held our great space-flier, gleaming in the brilliance of the lights about it, and just inside that clear space stood the World President, a half-dozen officials beside him.

As we paused there for that moment, Marlin's face grave and intent with purpose, Whitely coolly looking about him, and Randall and I endeavoring to conceal the excitement that pounded at our hearts, the whole scene was imprinted indelibly upon my brain. The crowds and brilliant lights about and beneath us, the great space-flier's faceted bulk looming into the darkness, the colossal buildings of the great world-capital that stretched away in the darkness in all directions, a great mass of shining lights among which swirled a packed sea of humanity gazing up toward our flier—these formed a mighty panorama about us, but in that moment we turned our gaze up from them, up toward the great constellations of summer stars that gleamed in the black skies overhead. Away in the southern skies, not high above the horizon, burned the equatorial constellations, Scorpio and Sagittarius and Capricorn, with the calm white light-globule of Jupiter moving in Scorpio and the bright red dot of Mars and yellow spark of Saturn in Capricorn. But it was toward Sagittarius that we were gazing, for among that constellation's stars there shone also Neptune, invisible to our unaided eyes but almost seen by us, it seemed, in that tense moment.

Then we four were moving across the roof toward the looming framework that upheld the space-flier, pausing inside its clear space to face the World President. It was a moment of cosmic drama, that moment in which Earth and the silent peoples of Earth, that had gathered in millions there to watch us, were sending forth four of themselves into the trackless void for the first time, sending them forth with Earth's one chance for life in their hands. The World President, facing us, did not speak, though; did not break the thick silence that seemed to lie over all the mighty city. He reached forth, gripped our hands with his own, grasped them tightly, silently, his steady eyes upon ours, and then stepped back. And then Marlin leading, we were clambering up the framework to the flier's screw-door, passing silently inside and then screwing that great door hermetically shut behind us. That done, we passed across the little vestibule-chamber and through the second screw-door, closing it likewise behind us.

Then, clambering up to the four suspended chairs in front of the control-panels, we took our places in them; Marlin in the right chair, his telescope and astronomical equipment before him, I in the next one, with the six controls of the space-flier's movements before me, Randall in the third chair, the recording dials and minor controls of the flier before him, and Whitely in the fourth or left chair, the dials and switches of the generators before him. Seated there, the constellation of Sagittarius and the other southern stars were full before us in our big window, for our space-flier was so supported in its framework that by turning on its great force-ray from the lower ray-opening we would be shot out by the terrific repulsive force straight toward Sagittarius, toward Neptune, slanting out tangent-wise from Earth's surface. And now Marlin was peering through the short, strange-looking tube of the telescope, was touching its focusing wheels lightly, peering again, and then turning to me.

"Neptune," he said quietly. "We'll start when it reaches the center of this telescope's field of view—when the flier is pointed directly toward it."

"But we can maneuver the flier in any direction in space, could head out from Earth and then toward Neptune," Randall commented, as I applied my own eye to the telescope, and Marlin nodded.

"We can, but by starting straight toward Neptune we'll use less of our generators' power."

While he spoke I was gazing through the telescope, and though I had gazed upon Neptune many times before it was never with such feelings as gripped me now. Like a little pale-green spot of calm light it was, floating there in the darkness of the great void, its single moon not visible to me even through the powerful telescope. Then as I straightened from the telescope's eye-piece Marlin had taken it again, gazing intently into it now, to call out to me the moment when the planet reached the center of its field of view, when our space-flier would be headed straight toward it. For it was then, as Marlin had said, that we planned to hurtle out toward the planet with all the power of our great force-rays, not only reacting but pushing against Earth as light pushes. But since we must necessarily change our course once in space, to allow for Neptune's own movement among other things, we would use less power by making our first start straight toward it.

Now, as we sat tensely there, I had turned, nodded to Whitely, and he had thrown open the switches before him that controlled the great generators, their throbbing suddenly sounding behind us as they went into operation, generating the force-vibrations that in a moment would be released backward from our flier as mighty force-rays. As Whitely moved the switches, the throb of the generators died to a thin hum, then rose to a tremendous drone, and then slowly sank to a smooth throbbing beat at which he rested the switches. And now Marlin, beside me, was calling out to us the divisions of the specially-designed telescope's field, as Neptune passed across them to the zero mark at which we would hurtle outward.

"—45—40—35—30—"

As his steady voice sounded periodically beside me I sat as though a poised statue, my hand upon that lever among the six lever-switches before me that would send the power of our throbbing generators stabbing out with colossal force from the flier's ray-opening behind us, that would send that flier hurtling outward. "—25—20—15—." As the calm voice of Marlin broke the silence beside me I felt my heart racing with excitement, saw that Randall, and even Whitely, beside me, had hunched tensely forward as the moment approached. I glanced out a moment through the flier's windows, seeing in a blurred impression the breathless, watching crowds, the brilliant lights. "—10—5—zero!" And as that last word sounded I threw open in one swift motion the lever-switch in my grasp!

The next instant there was a colossal roaring about us, we seemed pressed down in our chairs with titanic, crushing force, and saw crowds and lights and great buildings vanishing from about our flier with lightning-like swiftness as a great pale ray of light, of colossal force, stabbed down and backward from the flier's ray-opening behind us! In a split-second all about us was blackness and then the great roaring sound about us had ceased, marking our passage out past the limits of Earth's atmosphere! Now through the windows before and about us, as we clung there, we saw the heavens around us brilliant with the fierce light of undimmed hosts of stars, while as our great flier reeled on at mounting speed into the great gulf, we saw behind and beneath us a great gray cloudy ball that was each moment contracting in size. Earth was receding and diminishing behind us as we flashed out through the void toward distant Neptune, to save that Earth from doom!

We sat again in our chairs before the control-panel, Whitely to my left, gazing through the big window before us ... soaring past the limits of Earth's atmosphere.

CHAPTER IV

Through Planetary Perils

"Mars ahead and to the left—we ought to pass it in three more hours!"

At my words Marlin nodded. "We won't be bothered much by the pull of Mars," he said.

We sat again in our chairs before the control-panel, Whitely to my left, gazing through the big window before us. Ahead and above and all around us there stretched a great panorama, stunning in its brilliance, the vast panorama of the starry heavens as seen from the airless interplanetary void. Blazing in their true brilliant colors on all sides of us, the hosts of stars were like jewels of light set in the black firmament. And as our flier throbbed on through the great gulf of empty space at terrific speed, its acceleration still pressing us down somewhat in our chairs, we could see now amid the flaming stars dead ahead the far green spot of light that was Neptune, our goal, visible now to our unaided eyes in the clearness of empty space. Nearer toward us and to the right Jupiter was like a brilliant little disk of white light, now, the four white points of its greater moons visible about it. To the left, too, yellow Saturn shone much brighter, while nearer toward us on the left, almost beside us, hung the dull-red little shield, white-capped at its poles, that was Mars.

Behind us, by this time, Earth had dwindled to a steady spot of bluish light that was like a tiny moon, the smaller spot that was Earth's moon gleaming near it. Hardly visible as Earth was in the blinding glare of the great sun that beat upon us from behind, its great corona and mighty prominences appalling in their splendor, yet it was visible enough to show how far from it out into the void our flier had already flashed. For forty-eight hours indeed, our great space-flier had rushed outward at a speed that had already reached over a million miles an hour, and that was steadily mounting still beneath the terrific reaction of our great force-ray, that great pale ray only visible at its ray-opening source, that was stabbing back with colossal power and by the reaction of that push sending us hurtling on at greater and greater speed. Out and out we had flashed, Randall and I relieving each other every four hours at the controls, and already now had almost reached the orbit of Mars, more than fifty million miles outward. Now, as Marlin and Whitely and I gazed out toward it, the red disk of Mars itself was but several million miles from us, to the left and ahead.

Gazing toward it, we could see clearly the great ice caps of the poles of Mars, brilliant white upon its dull red sphere, and could see clearly also the long straight markings upon it, a network of inter-connecting lines, that for long had been the subject of discussion and disputation among Earth's astronomers. It was with fascinated eyes that we gazed toward the red planet as we drew nearer to it, and now Randall had joined us, moving with great efforts against the acceleration-pressure inside the flier. Marlin, though, had turned the telescope by that time toward the crimson planet, was gazing intently toward it. Minutes he gazed before he straightened, shaking his head.

"There can be no doubt that those canals—those lines—are the work of intelligent creatures," he said. "I saw great geometrical forms that seemed structures of some sort, but our space-flier is moving at such tremendous speed that it's all but impossible to get a clear focus on the planet in the telescope."

We stared toward the red disk and its dark markings. "If we could but stop there—who knows what wonders Mars may hold, what science——," Whitely mused.

Marlin nodded thoughtfully. "Neptune's our goal, and we can't stop for Mars now, whatever may be there. But if we succeed in our great task, if Earth is saved from this doom that Neptune's beings are loosing on the solar system, we'll come yet to Mars—and to all the others."

"In the meantime," I told them, "Mars is pulling our flier out of its course more and more. I thought our speed would take us by it, but it seems we'll have to use another ray."

For even as we had gazed toward the red planet, I had noted from the dials before Randall that the gravitational pull of Mars upon our space-flier from the left was becoming more and more powerful as we approached it to pass it, and that it was pulling us slowly toward it out of our course toward Neptune. Our deviation to the left was not great as yet, but even the slightest deviation we could not permit, since not only must we head as straight toward Neptune as possible to save time, but it was necessary that we avoid also the colossal force-ray which was stabbing from Neptune across the solar system toward the sun's edge, which was turning that sun ever faster. That great force-ray, invisible to us, but lying away to our left, we knew; would mean death for us if we blundered into it, would drive our flier with titanic force and speed straight into the sun!

So that now, as our space-flier moved nearer and nearer toward the distant red shield of Mars, pulled farther and farther out of its path toward Neptune, I swiftly manipulated the ray-direction dials on the control-panel, then grasped and threw open another of the six ray-opening switches. At once there leaped from our racing flier's side, from one of its ray-openings there, a second great force-ray like that which stabbed from the flier's rear toward Earth. This second ray, though, vaguely visible like the first at its source, but fading into invisibility in space, shot out toward the red sphere of Mars, away to our left. And in a moment more, as that light-swift ray reached Mars and pressed against the red planet with all its force, our flier was being pushed away from it, was being pushed back to the right, back into its original line of flight! Thus we hurtled on, the great rear ray of the flier pushing back with terrific force and sending us hurtling on through space, while the side-ray, striking Mars with lesser force, was sufficient to keep us out of the red planet's grip as we flashed onward.

Within a few hours more Mars was behind us, its red sphere fading rapidly into a crimson spot of light to the left and behind. The planet's two tiny moons, Phobos and Deimos, we had not yet seen despite our nearness to it, but it was with something of regret that we saw the crimson world and all the strange mysteries that we felt existed upon it, dropping behind us. Neptune alone, as Marlin had said, was our goal, and on toward its calm green light-dot we were rushing. I turned off our side-ray, therefore, which was no longer needed to counteract Mars's pull, and we gave all our attention to the panorama ahead. Save for Neptune's distant green dot, the only planets now visible amid the brilliant hosts of stars before us were Jupiter and Saturn. Saturn was shining ever more brightly to the left, its strange ring-formation already becoming visible to our eyes. But it was Jupiter that now dominated all the scene before us, his mighty sphere, its oblateness plainly visible, moving in majestic white splendor at the center of his four great moons.

It was not the planets ahead that held my attention now, though, as our throbbing flier raced onward, Mars and its orbit dropping behind. "The asteroids!" I exclaimed. "We're almost into their region now—will be among them soon!"

"And they're one of the greatest perils we'll encounter," Marlin said. "Hold ready to the controls, Hunt, for if we crash into one it means our end—the end of Earth's chance!"

I did not need his admonition, though, to make me tense my hands upon the control-switches, gazing intently forward. I knew we were now passing into one of the most dangerous regions of all the solar system—that great belt of whirling asteroids that lies between the orbits of Mars and Jupiter. More than a thousand in number, ranging from the great sphere of Ceres, 480 miles in diameter, down to the smallest asteroids of a few miles diameter only, they whirled there around the sun between the four inner and four outer planets, their orbits a maze of interwoven circles and ellipses. The greater part of them were so small, indeed, that at the tremendous speed with which our space-flier was flashing on they could be seen only in the moment that we rushed upon them. And yet in that moment we must whirl aside from any before us, since otherwise, pulled closer by the asteroid's own gravitational power, we would infallibly crash into it and meet our doom.

Steadily, therefore, we watched now, as hour followed hour, as our flier rushed on with speed still slowly mounting, traveling finally at more than two million miles an hour. The throb of its four great generators was as steady as ever, and the pressure of its decreasing acceleration still weighed upon us, but already we had become accustomed to that pressure. So now while I gazed forth with Marlin ahead, Randall was at one of the right windows and Whitely at one of the left, keeping a similar watch. And it was Randall, a few hours later, who sighted the first of the asteroids. He uttered a swift exclamation, pointing to the right and ahead, and as we looked there we saw a small bright point in the blackness of space, a point that with the swiftness of lightning was expanding into a great, dull-gleaming sphere, rushing toward us and drawing our space-flier toward itself! A moment we saw it rushing thus toward us, a great sphere of barren, jagged rock, airless and waterless, turning slowly in space; and then it was looming gigantic just beside us!

In that moment, though, my hand had jerked open one of the six levers before me, and instantaneously had shot from our flier's side a great force-ray toward that looming asteroid beside us. The next instant the asteroid's giant rock sphere seemed to flash away from us and disappear with immense speed, but in reality it was our flier that had been pushed away from the asteroid with colossal force by the force-ray I had shot toward it! Instantly I snapped off that ray, the space-flier flashing on in its straight course as formerly. And as I did so Marlin turned for a moment from his watch at the window toward me, gestured to the right toward the asteroid from which we had so narrowly escaped. In the moment we had seen it, I had estimated that one to be a hundred miles or more in diameter.

"That would be Vesta," he said, "one of the largest. It's the only one of that size in this part of their region now."

"Large or small, I want to see no more of them that close," I said. "Especially when——"

"Hunt!—look—to the left!"

It was Whitely who had cried out to me, and as I whirled to gaze in the direction in which he pointed, I noticed another swift-expanding sphere of rock, another gleaming asteroid rushing obliquely toward us! Not as great in size as the first one, but it was approaching us with terrific speed, and even as I jerked open one of the switches before me, sent a force-ray stabbing from the flier toward the rushing asteroid, it seemed that that asteroid was touching us, its great rocky surface shutting out all the firmament as it towered there beside us! My ray, though, had been shot forth just in time, had whirled us aside from the onrushing monster's path at the last moment, and as we reeled on, it too had vanished behind us. But now I had glimpsed two larger ones ahead and to the left, and was jerking the flier away from them also.

Still we were racing onward, our great space-flier hurtling on and on through that asteroid-filled region, escaping those great rushing spheres of death, sometimes by the narrowest of margins. Hour upon hour, keeping our sleepless watch at the flier's windows, we flashed on, its colossal speed still mounting as more and more of our generators' power was turned into the great rear force-ray that pressed back towards Earth and that shot us outward. By that time Earth had become but a bright white star behind us, the sun's size and brilliance decreased by a third or more already. But it was not backward we were gazing; it was ahead. We were striving with all our powers to avoid the asteroids that hurtled about us. We saw, once or twice, families or groups of those asteroids moving together, sometimes dozens together, and strove to give these a wide berth. On we raced, veering now to this side and now to that, with Jupiter looming ever greater ahead and to the right as we approached the end of the asteroidal belt. But it was as we approached its end, at last, that our greatest peril came suddenly upon us. For I had shot the space-flier sidewise with terrific speed to avoid an onrushing small asteroid, and the next moment when it slowed its sidewise rush, found that I had unwittingly shot it into the very heart of a great family of full two-score of the little planets!

All about us in that moment it seemed were asteroids, gleaming spheres at the very center of whose swarm our flier flashed, and into which by some miracle our sidewise rush had projected us, unharmed! I heard the hoarse cries of Marlin and Randall beside me, in that moment, the shout of Whitely, and knew that only another miracle could ever take us out of that swarm unharmed. Already, in that split-second, three of them were looming great to our right, another one ahead and to the left, and to escape one was to crash upon another. There was no time for thought, no time for aught save a lightning-like decision, and in that fractional instant I had made that decision, and as our flier hurtled through the great swarm of asteroids, had shot out its great force-rays to right and left and above and beneath us, driving out in all directions from our flier as it flashed through the great swarm!

There was an instant in which the space-flier seemed to be jerking and flashing in wild aimless flight amid that swarm, as its striking force-rays pushed it now to one side and now to another, away from the asteroids about us. Were two of those rays to strike asteroids in opposite directions, balancing each other, the space-flier, instead of being pushed aside, would be crumpled to instant annihilation between the push of the two great rays, I knew, and we expected nothing but annihilation in that mad moment as we shot on. But after reeling to right and left with dizzy speed for a crazy instant, the asteroids of the swarm had vanished suddenly from about us as we shot out of that swarm! We had escaped, had escaped a death that for the moment had seemed certain to all of us, and that I had managed to evade by instinct and luck rather than by reason.

There was an instant in which the space-flier seemed to be jerking and flashing in wild aimless flight amid that swarm, as its striking force-rays pushed it now to one side and now to another, away from the asteroids about us.

"Close enough—that!" I exclaimed as we raced forward through the void on our straight course once more. "If we meet many more swarms like that, our chances of getting to Neptune are small!"

Marlin shook his head. "We seemed gone that time," he admitted. "But I think we're almost out of the asteroidal region now—we should be crossing Jupiter's orbit in another twenty-four hours."

"The space-flier's doing four million miles an hour now," I said, glancing over at the space-speed dial. "We're beginning to feel Jupiter's pull a little already."

We were, indeed, already deviating a little to the right from our straight course in answer to the gravitational pull of the tremendous mass of Jupiter, looming ever greater now ahead and to the right. We were to pass it by some fifteen million miles, more than twice the distance at which we had passed Mars, but the colossal planet, larger than all the other planets of the sun together, was already attracting us strongly despite our terrific speed and momentum. For the time being, though, we gave it but scant attention, concentrating our attention, as we did, upon the watch for farther asteroids, since we had not yet emerged from their great belt between the orbits of Mars and Jupiter. Sleepy and weary as we were from our hours upon the watch, we dared not relax from that watch, and so Whitely and Marlin and Randall still kept up their constant survey of the surrounding void, while I held the flashing space-flier's controls, turning more and more of our generators' power into the great force-ray that was hurtling us on. We had not dared to use the generators' power too swiftly upon our start, lest the too great acceleration kill us, despite our shock-absorbing apparatus. But steadily our speed, already colossal, was mounting, and we were racing on through the gulf toward the distant green spot of light that was Neptune.

On and on in those hours we shot, until it seemed to me, seated there at the controls, that always we had flashed thus through endless realms of tenantless space. For now but a few asteroids were sighted by our watching eyes, and the eventlessness and strange tension of our rush onward through space made it seem like a strange flight in some unending dream. On and on, with Marlin and Randall and Whitely watching ceaselessly about me, on with the throbbing of our generators beating in my ears in unhalting rhythm. Behind us Earth's bright white star was steadily growing smaller, but still our great force-ray, stabbing ceaselessly back from our flier with colossal power, was sending us racing on faster and faster with its huge reacting force. But our start from Earth, days, hours, before, the great mission upon which we were speeding outward to Neptune, these things I had forgotten, almost, as the dream-like quality of our onward flight gripped me.

But as we raced still onward, as Jupiter's mighty sphere loomed greater and greater to the right ahead of us, my bemused faculties were shaken into wakefulness by the necessities of our situation. By that time we had passed out of the dangerous asteroidal region, and with their watch no longer necessary Whitely and Randall, after preparing for us all a quick hot meal from the thermos-cans in which all our food supplies were packed, had taken to their bunks for some much-needed sleep. Marlin sat beside me as we rushed on, his astronomical preoccupation holding him to a contemplation of the great planet, despite his own weariness. And weary enough he was, and I too, since for almost forty-eight hours we had been flashing through the perils of the asteroidal belt. It was now the beginning of the fifth day since our start from Earth, and already for a hundred hours we had been flashing at tremendous and mounting speed through the airless void. Like Marlin, though, I forgot my weariness in the spectacle of giant Jupiter, to the right and ahead.

For it was a spectacle of magnificence, indeed. Swinging like a giant disk of soft white light in the blackness of space to our right, Jupiter spun amid its four greater moons, the smaller moons being of diameter too small to be seen with unaided eyes even thus close. But of the giant sphere of Jupiter, of that great sphere's surface, nothing was to be seen. For all the mighty planet's surface was covered by the colossal masses of great clouds that enclosed it, floating in its dense atmosphere and encircling it in great belts, the mighty cloud-belts that for long have been to astronomers the most characteristic feature of Jupiter's surface. So that, though Marlin with the aid of the telescope, sought to gain a glance through some opening in the clouds at the great planet's surface, he failed in the attempt.

In a moment, however, he concentrated his attention upon the one visible feature upon the mighty world's surface, the great red spot that we could plainly see now as a pink area beneath the shrouding clouds, in the planet's southern hemisphere. At sight of it, Marlin had prepared and trained his spectroscope upon it, but after observations of a few moments he raised his head, perplexed. He glanced about him for a moment, then seized the bolometer, which by virtue of its new "shielded" principle was able to record accurately the amount of heat radiating from any one point of a planet or star, as well as from the whole planet or star. But upon checking its reading for a moment, after turning it toward the pink area of the great red spot, Marlin straightened from it also, shaking his head.

"It's strange, Hunt," he said, turning toward me. "It's always been believed that the great red spot is a part of Jupiter's surface still molten and flaming, but the spectroscope and bolometer show that it can't be."

"Strange enough," I admitted, gazing myself toward that glowing pink area on the mighty planet. "If we could but stop and explore the planet—but we must keep on toward Neptune."

"We must keep on," Marlin repeated, "but some day it may be, if we can save the solar system from the doom that hangs over it now, we'll come back here to Jupiter, will see for ourselves its surface."

By this time the great planet was almost directly to our right, its giant cloudy white sphere seeming to fill all space, despite the fact that it was more than fifteen million miles from us, and its four big, greater moons revolving about it. Hours before I had shot a force-ray toward the great planet from our flier's side, to counteract its growing pull upon us, but now as we came level with it, were passing it, that pull upon us was so enormous that it was only with a force-ray of immense power that I was managing to keep the space-flier from being drawn inward. Passing thus close, Jupiter's stupendous cloud-belted sphere was an awe-inspiring sight, whirling at immense speed also, since the great planet, more than a thousand times greater than Earth, rotates upon its axis at hardly more than a third of Earth's rotatory period or day, its day being less than ten hours. And passing it thus, too, the great red spot upon its lower half was an even greater enigma, for that gigantic pink oval was, we knew, fully thirty thousand miles in length, greater by far than all our Earth.

It was with awe that Marlin and I, and Whitely and Randall who had awakened now to relieve us, stared toward the gigantic monarch of the sun's planets as it dropped slowly behind on our right. A side-ray of colossal power it had taken, indeed, to hold us out from the great world's pull, and only slowly could we decrease that ray's power as we moved farther out from it. But now at well over four million miles an hour, we were flashing out beyond Jupiter's orbit, and ahead there was gleaming brighter to the left the yellow spot of light that was Saturn, the last planet that we must yet pass before reaching Neptune, since Uranus was in conjunction in regard to Neptune, being far on the other side of the solar system from us. And as Randall now took my place at the controls, I pointed toward the little yellow-glowing, ring-circled disk of Saturn ahead and to the left.

"Keep the flier heading straight toward Neptune, Randall," I told him. "We're going to pass Saturn uncomfortably close as it is, and we don't want to take any chances with it."

Randall nodded, his gaze shifting from the steady green spark of Neptune far ahead to the growing yellow disk of Saturn. "I'll try to keep her straight," he said, grinning, "though I'm beginning to wish that, if there's to be trouble, it had come back on Mars or Jupiter."

I smiled a little as I swung back from the control-panel along the flier's inside wall. I went from handhold to handhold with the pressure of its acceleration still upon me, until I had thrown myself into my metal bunk to fall almost instantly asleep, and to dream nightmare dreams of rushing on through endless space toward a goal that ever receded from us. And in the hours that followed, in the next three days that our space-flier shot on and on with Saturn growing ever greater ahead, the nightmare quality of my experience persisted. It seemed impossible, at times, that we four were in reality doing that which men had never done before; that we were flinging ourselves out into the great void, out through the solar system toward the planet that was its last outpost. We were watching and eating and sleeping, indeed, like men in a dream, so strange and utterly unreal seemed to us this unending rush through unending space.

But though we slept, and ate, and watched at the control-panel like men in a dream, there were times in those hours when realization of our position, of our great mission, came sharply home to us. Those were the times that Marlin trained his instruments upon the sun, which had by then dwindled to a tiny blazing disk behind us. And with those instruments Marlin found that the sun was still spinning ever faster and faster, its rotatory period decreasing still by the same amount each day, its day of division and doom steadily approaching. And with his own recorders Whitely found that the colossal force-ray from Neptune still was stabbing toward the sun, still turning it faster and faster toward its doom and that of its universe. That great force-ray, we found, was stabbing toward the sun on a line between our flier's course and Saturn, but was on a somewhat higher level, so that in reality the great ray did not lie between our flier and Saturn but above both.

The consciousness we had of that great ray's existence and the knowledge we had of the doom it was loosing upon the peoples of our world served to prevent the dream-like lassitude of our conditions from overpowering us, and we were further awakened by the swift expansion of Saturn, ahead, as our flier neared it. For by then the great faceted ball of our flier was hurtling on through the void at five million miles an hour, slowly approaching the limits of its speed as our mighty rear force-ray drove us forward with tremendous power. And at that speed, in the next three days, Saturn loomed larger and larger ahead, until we saw at last that upon the fourth day's beginning we would pass the mighty planet. And at that our interest rose to excitement, because we would pass closer by Saturn than any of the planets in our straight flight out to Neptune, passing it indeed by no more than a million miles. So that as the last hours of those three days passed, we observed the big, yellow-glowing disk of Saturn ahead with intense interest.

And a strange sight indeed was great Saturn as it loomed greater before us and to the left, for strangest of all the sun's planets to the eye is this one. Greatest of all the planets save for mighty Jupiter, its huge sphere seemed even greater than Jupiter by reason of the colossal rings that encircled it, and by its nine greater moons that revolved about it. A solar system in itself seemed Saturn, indeed, its huge rings tilted somewhat, those great rings themselves tens of thousands of miles in width and thousands of miles from the planet they encircled. We could see, as we drew nearer toward the great planet, that those rings were in fact what had long been known by Earth's astronomers—gigantic flat swarms of meteorites and meteoric material revolving about the great planet at immense speed. Of the surface of Saturn, though, no more could be seen than of that of Jupiter, since like Jupiter the great planet was wreathed in colossal cloud-belts.

Marlin shook his head as he gazed toward the great ring-girdled planet, almost filling the heavens beside us. "It is well for us that Saturn is not our goal," he said. "Those titanic meteoric masses that are the rings—to blunder into them would mean instant annihilation."

Whitely nodded. "As it is," he said, "there must be many meteors in this region about Saturn—many that have broken loose from the rings or are flying toward those rings."

"Let's hope that you're wrong on that, at least," I told him. "We'll soon be passing within a million miles of those rings, and I want to meet no meteorites—not after our experience with the asteroids."

By then, indeed, we had drawn almost level with Saturn, its huge sphere and colossal rings almost directly to the left, the edge of those rings, but a half-hundred miles or less in thickness, being a scant million miles or more from our racing space-flier. The great maze of the planet's nine greater moons seemed crowded now upon its other side from us, Titan, largest of those moons shining brilliantly as a small white disk near the huge yellow bulk of Saturn and its colossal rings. Before then indeed, I had been forced to shoot out from the flier's side a force-ray toward Saturn, to counteract the great planet's pull upon us, but though it loomed beside us now almost as immense as great Jupiter itself, its recorded pull upon us was many times less. This was due, I knew, to the comparatively small mass of Saturn, since though of immense size and possessing a vast atmosphere, it is known to be the least dense of all the planets, being of less than 0.7 the density of water.

Even so, however, it was requiring a force-ray of great power to hold our rushing flier out from the huge planet. Though lesser than Jupiter's, its pull upon us was great, nevertheless. And now that we were passing the huge world so closely, it seemed to us with its vast rings and great family of whirling moons to be of universe-size itself, so mighty did it loom beside us. The great rings, of small thickness compared to their huge width and circle, were edge-on to us now, a million miles to the left, and we could see that they were in reality but vast swarms of countless meteors, great and small, whirling at great speed about Saturn and forming by their division three rings, the innermost a darker one. Yet despite their strange appearance and colossal size, it was not the great rings that held our interest so much in that moment as the cloud-hidden surface of Saturn itself. For even as in passing Mars and Jupiter, we were gripped with desire to veer in toward the planet and explore the strange wonders that might exist upon it, or upon its greater moons. But none suggested that thought now. All four of us knew that only the growing green spot of light, that was distant Neptune ahead, must be our goal.

As the flier raced on, almost passing the huge planet now, Randall uttered a swift exclamation, pointing ahead and to the left a little. At the same moment, though, I had seen the thing that had caught his eye—a small dark point growing with lightning swiftness as it rushed toward us; a great dark meteor, perhaps five hundred feet in diameter, rushing toward our flier, whirling far out from Saturn's rings in the same direction as those rings! Instantly, upon seeing it, I had turned more power into the ray that held us out from Saturn, and as we were pushed sidewise in the next moment by that increased power, the big meteor had flashed past us far to the left! And a moment later, I had caught sight of two similar meteors, one smaller than the other, rushing toward us in the same direction from ahead. But these I had seen soon enough to avoid collision.

It was evident that, as Whitely had suggested, we were encountering some of the stray meteors that might be expected to whirl here far out from the meteor-swarms of the great rings. And as we watched tensely now for more meteors, it was with something of awe that we gazed toward the huge rings, that we knew to be rushing swarms of countless similar meteors. It was well, as Marlin had said, that we were not called upon to penetrate through or around those great rings, since in their awful whirling swarms of meteors no craft would be able to live even for a moment. But our space-flier was passing the midmost point of those rings; already huge Saturn was beginning to drop a little behind us; and we breathed more freely. And, ironically enough, it was at that very moment of our relief that catastrophe came upon us. There was a wild shout from Marlin, and simultaneously I saw a huge round dark mass looming dead ahead and whirling toward us. Just as I snapped open the control-levers, that great dark meteor's mass had struck our onrushing flier with a tremendous stunning shock!

For an instant, as the flier reeled and spun there crazily in the gulf of space, it seemed the end to me, but in a moment more I realized that the great faceted walls had not been penetrated, for the air in the flier was unchanged. Had those walls been pierced, the result would have been the instant freezing to death of all of us. But that death had not as yet come upon us, and as I struggled forward in my chair I saw that the space-flier was still whirling crazily around from the shock and that the throbbing of its great generators had ceased. Beside me Marlin and Whitely and Randall were coming back to realization of their surroundings after that colossal shock, Whitely bearing a nasty cut upon his temple. And as Marlin sprang to the flier's side-window, gazed obliquely from it, he uttered an exclamation.

"That meteor just grazed us!" he exclaimed. "If you hadn't jerked the controls over at the last moment, Hunt, it would have hit us head-on! As it is, it smashed through the flier's outer wall, but didn't pierce the inner wall!"

"But the generators!" cried Whitely, who had been fumbling at their switches. "They've stopped! When the meteor crashed through the outer wall it must have broken some of our generator-connections between the two walls!"

"And the flier's falling!" I cried in turn. "It's falling toward Saturn now, with its force-rays dead—we're falling into the great rings!"

For as I glanced outward I had seen that was what was happening. The halting of the generators by the breaking of their connections between the flier's double walls had halted also the force-rays that had been pushing us out toward Neptune and that had been holding us out from Saturn's pull. With the halting of those rays the pull of the mighty planet had at once gripped our space-flier and now we were moving at swiftly-accelerating speed toward that planet's mighty bulk, toward the great rings but a million miles to our left! Were falling helplessly, faster and faster each moment, toward those mighty rings, toward their vast swarms of whirling meteors in which our space-flier and all within it could meet only an annihilating death!

CHAPTER V

At the Solar System's Edge

"Out of the flier!" Marlin cried to us. "Our one chance is to get out and repair those broken connections from the outside."

"But how——" Randall began, when the astronomer broke in on him. "The space-walkers! In them we can get outside, can try to repair those connections before we fall into the great rings!"

A moment we stared toward him in sheer surprise, and then as one we were leaping toward the four big space-walkers, suspended from the flier's wall. For though we had not dreamed, in taking them with us, of any such emergency as now confronted us, we saw that, even as Marlin had said, our one chance to escape the annihilation that soon would be ours otherwise lay in their use. Swiftly, therefore, we unhooked the great cylindrical space-walkers, neither they nor aught else in the flier having any but small weight now, that weight being the result of the pull of great Saturn, toward which we were falling. Quickly swinging open the section near the cylinder's base that was its door, therefore, I pulled myself up into the cylinder, then closed its hermetically-sealing door with the small inside lever provided for the purpose.

I was standing, therefore, in a metal cylinder seven feet in height and three in diameter, its top tapering into a rounded little dome in which were small windows from which I could look outward. My arms I had thrust into the great hollow jointed arms of metal that projected from the cylinder's sides, and had at my fingers' ends inside those arms the controls of the great pincer-hands in which those arms ended outside, and the control also of the small generator inside the cylinder whose little force-ray was shot down from the cylinder's bottom. This could be shot straight down, sending the space-walker upward by pushing against some larger body, or could be shot out obliquely sending the space-walker horizontally in any direction. Once inside the space-walker therefore, with its tiny generator throbbing and the equally small air-renovator and heater functioning, I was ready to venture out into the airless void.

Glancing out through the vision-windows I saw that Marlin and Whitely and Randall had struggled into their space-walkers also, and were signalling their readiness. We grasped therefore the tools and materials we had hastily assembled for our task, these being spare plates to repair the flier's outer wall and a small molecular-diffusion welder, and then with those in the grasp of our great pincer-hands were pulling ourselves toward the flier's screw-door. In a moment we had that open, and were crowding into the little vestibule-chamber which lay between the outer and inner doors. Closing the inner one tightly behind us, we swiftly screwed open the outer door. As it opened there was a rush of air from about us as the air of the little vestibule-chamber rushed out into the great airless void outside, and then Marlin was leading the way out of that door, out into sheer space outside our falling space-flier!

I saw Marlin drawing himself in his space-walker through the door and then floating gently out that door, floating in space a few feet from our flier and falling at the same rate as it toward mighty Saturn! In a moment more I was following him, Whitely and Randall behind me, and as I too propelled myself with a slight push through the door, my cylindrical space-walker floated outward. I found myself, therefore, cased within that space-walker's cylinder, and floating in it in the sheer empty void of interplanetary space! Beside me was the great gleaming faceted ball of our flier, falling at the same rate as ourselves toward the huge rings of mighty Saturn, to the left. Beneath and before and on all other sides of me, though, was only space, the tremendous gulf, gleaming with the great hosts of stars on all sides, with the sun's brilliant little disk shining far behind us. For the moment our position was so strange, so utterly alien and unprecedented, as we four floated there beside the falling space-flier in our four great metal cylinders, that we could only gaze about us in sheer awe and wonder. Then Marlin, with one of the great metal jointed arms of his space-walker, motioned to us and toward the flier, and we realized that we had but little time left in which to accomplish the task now before us.

For with every moment the flier and our four space-walkers were falling at greater speed toward the colossal rings of huge Saturn, to the left, and the whirling titanic meteor-swarms of those rings were growing larger and larger. But a few hours remained before, with the growing acceleration of our free-falling flier, it would be meeting its end in those clashing, crashing meteors of the great swarm, so that if we were to repair the damage to it, and get its generators functioning again before it met its doom, we must work fast. Our four space-walkers were falling toward Saturn at the same rate as the great flier beside us, so that we hung just beside that flier in space without need to use the propelling force-rays of our four cylinders. And now Marlin, grasping with his great metal-pincer hands one of the projecting joints of the flier's great faceted walls, was pulling himself around it even as he fell with it through space, was pulling himself around to its other side, where the meteor that had struck us a glancing blow had done its damage.

In a moment Whitely and Randall and I had followed, moving clumsily in our great cylinders as we fell with the flier on toward Saturn's rings, and as we reached the other side where Marlin was hovering now in his space-walker we saw that the meteor that had grazed us had demolished two of the great facets of the flier's outer wall, and had shattered and crumpled a third. Save for a slight denting, though, the inner wall seemed unharmed, a fact that alone had saved us, but the black cable-connections between the walls were broken in a half-score places, we saw. It was that severing of the connections that had halted our great generators, we knew, so now our first task was to repair those connections, and it was upon that task that we began at once to work. Surely never had men worked under stranger circumstances than those, was my thought as we began the work of re-matching the severed connections. For we four, cased in our four great cylindrical metal space-walkers, were falling through space at a tremendous and ever-increasing rate, even as we worked upon our great flier falling with us, we were falling through the mighty void toward the whirling rings of Saturn, looming immense in space beside us. It meant annihilation for us, if we could not complete our repairs in time to escape them!

And as we toiled there at the connections, it seemed to me that never could we complete them in time to escape the great rings. For not only were there a half-score breaks in the intricate cables, but each cable held within itself a dozen smaller connections or strands that in each break must be exactly rematched. And working as we were with the great pincer-claws of the space-walker our progress was terribly slow. Minutes passed into an hour and another hour, as we labored furiously there outside the flier with those connections, and by then it seemed to us that the colossal rings of Saturn, a huge whirling storm of meteors, were but a few minutes from us, so vastly did they loom before us, and so swiftly were we and our flier falling. With the energy of utter despair we labored on there at the seemingly endless task of rejoining the intricate connections, our tools and materials that we were not using at the moment being simply released by us beside us, since they fell with us and our flier at the same rate toward Saturn and thus were within our grasp, our tools floated there beside us!

Now we were approaching the last of the connections, but now too we saw that it was only a matter of minutes before our space-flier and we would be whirling into the edge of the mighty rings of Saturn, that loomed now gigantic in their spinning meteor-masses before us! Already meteors were driving about us in space more thickly, and only by a miracle had our helplessly-falling flier escaped them so far. It seemed impossible that we could complete our task before the flier and ourselves were shot into the crashing death of those colossal whirling meteor-swarms, but we were working with the mad energy of a forlorn hope, and now too Marlin was leaning toward us with his space-walker to shout something to us. For when one space-walker touched another, their two occupants could hear each other's shouts, the sound-vibrations carried through the touching metal sides. Marlin was crying to us that but minutes were left us, and was ordering Randall to return back inside the flier and stand ready there to shoot it away from the great-looming rings the instant that the connections were repaired!

In a moment Randall had obeyed, pulling himself around the falling flier to its door and inside, while Marlin and Whitely and I worked tensely upon the last of the connections, matching and joining them with the greatest speed of which we were capable. Now it seemed that greater meteors were all about us, and now the huger, denser masses of the mighty rings were towering vastly beside us, as at plummet-like speed our flier and ourselves whirled toward them and toward death! Hanging there in sheer space at the falling flier's side, working madly upon those last connections, with all about us the glittering hosts of the stars and with beside us the titanic bulk of great Saturn and its colossal rings, we seemed caught in some unreal and torturing nightmare. Then as the huge meteor-masses of the mighty rings loomed just beside us, as I reached with the pincer-hands of my space-walker toward the last of the connections, I heard from Marlin in the space-walker touching mine a hoarse cry of despair. But at that last moment my claw-hands were swiftly joining the last connection and in the next instant came the steady throbbing of the great generators inside the flier! In that instant we had grasped our tools with one metal arm and with the other each of us had gripped the edge of the flier's shattered outer wall. And then, just as the flier and ourselves seemed hurtling straight into the mighty wall of whirling meteors that was the great rings beside us, the space-flier, with us three hanging desperately to it, was hurtling away from those rings as its great force-ray shot from inside toward them, was flashing at terrific mounting speed out from them into space!

For an instant, so terrific was the accelerating speed of the flier beneath Randall's control inside, that we three, hanging to the broken outer wall in our space-walkers, seemed on the point of being torn away from our grip on it, of falling back to Saturn once more. But in a moment more, with a great distance already between the flier and the huge rings that had almost been our doom, Randall had halted it, was holding it motionless in space by means of a steady force-ray. Then we were swiftly repairing the break in its outer wall, by means of the plates and tools to which we had clung, setting those great plates in place to replace the three shattered ones, and then welding them swiftly into the flier's outer wall integrally by means of the molecular-diffusion instrument. That done, we pulled ourselves around the flier's faceted surface to its outer door, opening that door and closing it again once inside the vestibule-chamber. Then as Marlin touched a stud the vestibule-chamber was filling with air, and in another moment we were inside the flier once more, were pulling ourselves out of the great space-walkers, with Randall already out of his and at the controls.

"That was almost our trip's end!" cried Marlin as he emerged from his space-walker. "Another few minutes and we'd have been inside the rings—would have been pounded into instant annihilation by the meteors there!"

I passed a hand over my brow. "Never again do I want to find myself in a situation like that," I said. "As it was, it was the space-walkers alone that saved us."

Marlin nodded, gazing out toward great Saturn looming gigantic still to our left. "If ever we come back," he said, "if ever we try to reach Saturn and explore it as we may some day, we'll have our work cut out for us. Those mighty meteor-masses—those rings——"

"Well, at present the farther we get from Saturn the better I'll feel," Whitely told us. "And I'm glad enough that there's no other planet between us and Neptune, at least, for Uranus is far away."

Now, recovering from the first shakiness of the reaction from our awful peril, we turned with Randall to the consideration of our position. Our great ray that had shot back from the flier, and had pushed us by its force out through the solar system, had been snapped out by the halting of the generators, and we had now only the side-ray that was holding us out from Saturn. I suggested, therefore, that for the remainder of our trip out to Neptune we turn the space-flier's rear force-ray upon Saturn instead of Earth, since Earth by now had dwindled to a small bluish-white star far behind. To train our rear force-ray upon Earth and to adjust the mechanism that kept the ray trained automatically afterwards upon the object suggested, would take more time than if we were simply to push the rear force-ray against great Saturn.

Marlin approved the suggestion, so after sending the flier out farther from Saturn and ahead of it by oblique applications of the side-ray, we held it carefully in space until it was headed toward the far green spot of Neptune, and then turned on the rear force-ray with half its full power at the start. At once, with terrific acceleration, we were flashing on toward Neptune, the giant power of the ray pushing against Saturn and driving our flier ever outward. So tremendous was that acceleration, indeed, that despite the shock-absorbing apparatus of our chairs we came near to being overcome by the awful pressure upon us. Yet it was necessary that we use the highest possible speed and acceleration, now, for our former speed and acceleration had been completely lost when the halting of the generators had allowed Saturn to pull us inward. And though we were now flashing out past Saturn's orbit, with only the orbit of Uranus between us and our goal of Neptune, we had still two-thirds of our journey before us! So colossal are the distances between the great outer planets, distances beside which the gaps between Mars and Earth and Venus and Mercury seem tiny.

With the utmost acceleration of speed that we could stand, though, our space-flier was now hurtling outward, its great force-ray pushing against Saturn with more and more power and sending us flashing forward with greater and greater velocity. In the next dozen hours of our flight we had reached again to the speed of five million miles an hour that had been ours before we had met with our misadventure at Saturn. And as we hurtled on Neptune was slowly largening before our eyes, its distant, tiny little spot of calm green light becoming bigger, brighter, though very slowly. But the eyes of Marlin and Whitely and Randall and myself were always upon that green light-spot as we hurtled on, hour following hour and day following day in our eventless onward flight through the solar system's outer immensities of space. And still our speed was steadily growing until at last, by the time we approached Uranus' orbit, we were flying through the great void at the space-flier's utmost velocity, more than eight million miles an hour.

That was a speed colossal, yet so accustomed had we four become to the space-flier's tremendous velocities that it seemed not unusual to us. Flashing through the void as we were, the only objects by which one could measure speed were the planets before and behind us, and these changed in size so slowly as to make our speed seem small. The greatest change to us in the attaining of the space-flier's immense utmost speed was the change of conditions inside the flier itself. Formerly the pressure of our constant acceleration had replaced to some degree the effects of gravitation, that pressure forcing us always towards the flier's rear, as we turned more and more power into our giant pushing ray, as we shot out with greater and greater speed. But now, with our utmost speed attained and that acceleration's pressure missing, we floated inside the flier as though entirely weightless, being attracted only very slightly toward the walls by the slight gravitational attraction of the flier's mass itself. So that now the straps across chairs and bunks and the handholds here and there on the walls that we had provided proved indispensable to us, indeed.

It was upon the fifteenth day after our start from Earth, the first day of July as I noted by Earth-reckoning, that we crossed the orbit of Uranus. As we approached that orbit, only our recording distance-dials, of course, marking the fact that we were nearing the path of Uranus, I stood or rather floated with Marlin and Whitely at the flier's rear windows, gazing backward. Behind us gleamed in the star-swept heavens the planets past which we had come, and those others beyond them. Great Saturn with his vast rings that had almost been our deaths was already dwindling fast, as our flier shot out from it with its force-ray pressing with ceaseless power against it. Already the huge ringed planet was but a tiny yellow disk of light to our eyes, so far out from it we were.

To the left, too, shone the white star of giant Jupiter, small but intensely brilliant still, while farther distant and infinitely fainter was the red spark that was Mars. Our eyes shifted from these to the bluish light-point that was Earth, and then beyond it to the little disk of brilliant fire that was the sun, its light and heat reaching us now in the smallest of quantities as we fled on into the chill immensities of the outer reaches of the solar system. There close beside that fiery little sun-disk we could also make out the silvery little light-point that was Venus, and by making use of a small hand-glass could also discern closer even beside the sun the tiny point of rosy light that we knew to be Mercury, smallest and inmost of all the planets. But as we watched there, as our space-flier hurtled on at unvarying, colossal speed over the orbit of Uranus, it was toward Uranus itself we were gazing. Far back from us on the solar system's other side hung the green spot of light that was Uranus, booming onward in its vast path around the sun, but though we watched steadily through the hand-glass toward it we were unable to make out the four small moons that accompany the great green planet, which shone with a deeper green even than the greenish spot of Neptune, ahead.

"Uranus—Venus—Mercury——," said Marlin, as he gazed musingly backward. "Those three we have not passed, yet they're no greater mysteries to us than those that we have passed. But some day——"

"Some day——," I repeated, staring back, lost in thought myself, not completing, any more than Marlin, the thought that I had started to express.

Nor did I need to complete it, for as Marlin and Whitely and I stared back to where the sun's disk sent its light bravely out across the unthinkable reaches of space that separated us from it, our thoughts were all on those three planets, on Uranus and Venus and Mercury, and on those others, Mars and Jupiter and Saturn, that we had passed. What wonders, unknown to us, might not exist upon any of those worlds? But they were wonders barred to us for the time, since time was the one thing of which we had the least, in our great rush outward to the sun's outermost planet, in our desperate race outward to attempt to save our own Earth from the doom that hovered over it. For still that doom cast its shadowing wing darkly over Earth, still Whitely's instruments informed us that the giant force-ray from Neptune was stabbing back toward the sun, turning the sun ever faster at the same remorseless rate. So that it was toward Neptune, after minutes, that we turned, taking our places in our chairs beside Randall, at the controls, and gazing with him toward the planet far ahead that was our goal.

And now that we had crossed the orbit of Uranus, some two-thirds of our colossal journey's length lay behind us, and Neptune was becoming ever brighter ahead, its pale-green spot of light having become almost as brilliant to our eyes as Saturn, behind us. As we viewed it through our telescope, too, we could make out the tiny light-point of Triton, the single moon of Neptune. Somewhat larger than our own moon was Triton, we knew, and we could see through our glass what had long been known by Earth's astronomers, that this single moon of Neptune's revolved about it in a plane sharply slanted or inclined to the plane of Neptune's equator, to the general plane of the ecliptic or solar system. And close indeed seemed the light-point of this single moon to Neptune, since we knew that it was at almost the same distance from the great planet as our own moon is from Earth.

It was toward Neptune and its little moon that our eyes turned now and in the hours and days that followed, while gradually our excitement became tense as the great planet loomed ahead of us. Soon it had become a perceptible pale-green disk, widening out as we shot on and on toward it. We would reach it, we calculated, upon the twenty-first day of our journey, twenty-one days after starting from Earth. An eternity it seemed, that period of three weeks, such vast realms of space we had come through, such tremendous perils we had dared and passed. But now all those perils and worlds we had passed, Mars and the deadly asteroidal belt, great Jupiter and Saturn and the doom that had almost been ours there, all these things faded from our minds as we found ourselves with our thoughts concentrated wholly upon the far planet that from the first had been our goal, that planet which we must reach if Earth was to be saved. For ever, ever, the great force-ray of Neptune was turning the sun faster, and now less than a hundred days remained before that turning sun would be no longer able to hold together, would be dividing and releasing fiery doom upon Earth and almost all its other planets.

What was awaiting us at Neptune? That was the question that was foremost in all our minds as we shot on in those last tense days. What manner of beings there would they be who, we had assumed, were stabbing this ray of doom toward the sun? What manner of beings could they be who could exist at all, if exist they did, upon such a planet as Neptune, a planet moving about the sun at the unthinkable distance of almost three billion miles? Upon a planet that could receive but a minute fraction only of the sun's light and heat compared to that received on Earth? Upon a planet which astronomers had always believed to be of far lesser density than Earth, of a density little more than that of liquids rather than of solids. Was it possible that upon this farthest of all the sun's circling worlds there could exist life of any kind, not to speak of life intelligent enough to stab across the solar system and spin the sun itself faster to its division and its universe's doom?

Those were the questions that throbbed through our brains now as our hurtling space-flier shot on and on, Neptune growing with each hour before us. By the nineteenth day its disk had expanded to such a degree that we were able to discern upon it the cloud-belts that had already long been seen upon it by Earth's astronomers. By the twentieth those great vapor-belts were plainly perceptible, and also Triton, its moon, had become visible to our unaided eyes, revolving close about the great planet in its sharp-slanted plane, being now behind the planet but so much above it as to be completely visible to us. By the twentieth, too, the sun behind us had become hardly more than a super-brilliant star, its tiny fiery disk bathing us still with a certain amount of light, although long before this we had ceased to rely upon its heat on our flier's sunward side and had had recourse to our own heating-mechanism. By this time too, of all the planets, only Jupiter and Saturn were visible behind us; the rest were invisible to us at the colossal distances which now separated us from then.

It was not behind but ahead, though, that we were gazing, as our space-flier flashed over the last portion of its great trip, as Neptune apparently grew in size before us. Seated in my control-chair, with Whitely and Marlin and Randall in their chairs beside me, I watched the mighty planet fascinated, as we hurtled on toward it in the early hours of the twenty-first day, that day that we had calculated would bring us to our goal. And truly, now, Neptune was looming in something of its true greatness before us. Only a tiny point of light in a telescope on Earth, hardly more than that on the long days of our journey outward, we saw it now in some size and splendor, a huge cloud-belted world as large almost exactly as Uranus, outrivaled in the solar system only by it and by the two giants of Jupiter and Saturn. Over sixty times larger than our own Earth it was, a huge world spinning far out here at the solar system's very edge, the last outpost of that solar system with beyond it only the awful emptiness of interstellar space.

Silently we gazed toward its great, green disk, its small gleaming moon, as our space-flier throbbed on toward it. Whitely, as usual, was checking from time to time the performance of the never-ceasing generators whose great force-ray, pressing against Saturn still, was hurling us forward. Randall was gazing forward with me, helping me now and then to ascertain from our speed and distance dials our distance from the great planet. Marlin had applied himself to the telescope, was gazing ahead through it toward the big world's cloud-wreathed surface, touching a focusing wheel now and then. For minutes we throbbed on thus, the beat of the generators the only sound in the hurtling space-flier's interior, but at last Marlin drew back from the telescope's eye-piece and frowned as he gazed toward the great green planet ahead.

"I can make out nothing through those cloud-belts," he said. "Those belts show, as astronomers have always believed, that Neptune has a great atmosphere. But what lies beneath them we'll not know until we penetrate through them to the planet's surface."

"That won't be long," I told him. "We're already only fifty million miles from Neptune—should reach it in seven or eight hours more."

"You'll be slowing the flier's speed before long then?" asked Whitely, and I nodded.

"We'll wait until we're ten million miles from it and then cut out our rear-ray that's pushing us on, and send out a front force-ray toward Neptune to break our progress."

Those next several hours, however, seemed to us in passing to be drawn out to infinite length, so great had become our suspense. At last, however, as we stared tensely ahead, Randall gave the word beside me that marked our place as within ten million miles of the great planet, which had now grown to a vast pale-green cloudy disk in the heavens before us. And as he gave that word I snapped shut one of the six switches before me, turning off the great rear force-ray of the flier, and at the same moment snapped open another switch that sent a great force-ray stabbing straight out from the ray-opening in the flier's front, stabbing straight out toward the great disk of Neptune ahead!

Almost at once our mad flight toward that huge world began to diminish in speed. Minute by minute the figures on the speed-dial crept backward, so that from eight million miles an hour our speed dropped quickly to six million, and then to four and to three and to two million.

With this swift decreasing of our speed we were experiencing now the reverse of that pressure that had been ours upon our acceleration, since now we were straining upward and forward against the straps of our chairs, the pneumatic shock-absorbing apparatus of those chairs functioning now as it had done then. But though we felt again the dizziness and slight nausea attendant upon these tremendous changes of speed, we forgot that in our intent contemplation of the huge world that loomed but a million miles ahead, its tremendous pale-green sphere, belted with great cloud-masses, seeming to fill the heavens before us. Already Marlin, with his instruments, had found as we neared Neptune that the giant world's rotatory speed was a little more than twenty Earth-hours, solving a problem that long had defied Earth's astronomers by the discovery that the great planet turned on its axis each score of hours.

An involuntary thrill of pride ran through me even as we shot in toward those great cloud-masses that encircled Neptune. Neptune! The sun's farthest world, and we four had reached it, had shot across the awful gulf that none had ever thought to span! Marlin, beside me, was gazing forward into the great cloud-layers now with the astronomical curiosity of all his career gleaming in his gray eyes, as we approached this farthest of our solar system's worlds. Whitely was contemplating it with his usual cool detachment, but thoughtfully. Randall's face was as eager with interest as my own must have been, and when, a little later, there came a low mounting roar of sound around our flashing space-flier, the roar of an atmosphere through which we were rushing, he uttered a low exclamation, swiftly manipulated our outside air-tester, and then turned to us.

"An atmosphere to Neptune, surely enough!" he exclaimed. "About twice the pressure of Earth's, even this far out, and the air-tester shows a large percentage of water-vapor and rather larger amount of oxygen. Otherwise it seems much the same as Earth's."

Marlin nodded. "We should be able to move in that," he said, "but the greater gravitation of Neptune will probably be such as to make it necessary to keep inside the space-walkers."

But now the space-flier was hurtling into the outer vapor-layers, that swirled about us in white mist-masses in the pale light that came to us from the tiny, distant sun. Onward and downward through those vapor-layers, through the cloud-belts about the great planet, our space-flier shot, while we four gazed ahead and downward, now with excitement keyed to an utter tenseness. Then with sudden stunning surprise, for we had thought those cloud-layers of immense thickness, our space-flier shot out and down from them, shot down into clear air, clear atmosphere. And as it did so, from the four of us came simultaneous cries. For there in the pale, dim unEarthly light there stretched far away beneath us the surface of the planet that for so long had been our goal on our great race to save Earth from doom, the surface of great Neptune!

CHAPTER VI

Into Neptune's Mysteries

"Metal, over all Neptune's surface!"

"A metal-covered world!"

Our stunned, astounded exclamation sounded together there as we gazed downward from our flier, whose drop I had instinctively halted. For it was metal indeed that lay beneath us, a gigantic surface of smooth dark metal or metallic substance that glinted dully in the pale light that fell on it, and that stretched away in all directions to the horizons, completely covering the giant planet Neptune as far as we could see! A metal-covered world! In amazement, in awe, we stared down upon it in that moment. For we had expected many things, many aspects which the surface of Neptune might have had, frozen ice-fields or flaming craters or even a liquid world, but never had we expected what we now saw beneath us. Never had we expected to find the huge planet thus sheathed in a dark metal covering that apparently extended over all its gigantic surface! And in all its vast smooth expanse, we saw, there was no higher structure of any sort, nothing but the level plain of smooth dark metal, sweeping far away to the flat horizons.

"Neptune a metal-covered world! And I think I see why, now," said Marlin quickly as we gazed down. "I think that I can understand why the beings of Neptune have covered their world with this shield——"

"But what lies beneath it?" Randall asked. "Do you mean that these beings of Neptune——"

"I mean that beneath this great shield they have built must lie the real world of the beings of Neptune—must lie the source of the giant force-ray that they're stabbing toward the sun!"

"But how to get down inside?" said Whitely. "There seems no opening in this gigantic metal shield——"

"We must go on, then," Marlin told us. "Must go on until we find some way of getting beneath, since beneath that shield there lies our goal!"

A moment we stared toward each other, and then I had snapped open one of the switches before me, turning the ray-direction dial, sending down slantwise toward the metal surface a force-ray, instead of the vertical ray that had upheld our flier. The pressure of this slanting ray at once sent our ball-like space-flier moving forward across Neptune's surface, across the smooth vast dark metal plain whose presence was so astounding to us. I glanced at the outside-temperature dial as we shot forward, saw that the atmosphere through which we moved though dense was cold indeed, hardly above zero in temperature. Then with Marlin and Whitely and Randall I turned my attention to the smooth great metal surface over which we were driving. On and on we shot, though, without finding any slightest change or opening or structure in that unending dark metal surface, that swept away in its vast, bare curve to the horizons, which were very far from us, so great was the radius of curvature of Neptune's mighty sphere. But after tense moments of this fruitless watch from our racing flier, Whitely uttered a low exclamation and pointed ahead, toward a round lighter circle in the dark metal plain far to the left, a circular opening in the giant metal shield!

None other of us spoke as we gazed toward that opening, but at once I had sent the space-flier rushing toward it. As we raced nearer to it we saw that that opening's circle was a full five hundred feet in diameter, and that we could see down through it a great, bright-lit space beneath! Tensely we watched, until in another moment I had sent the space-flier directly above the great opening, so that it hovered motionless above the circular opening's center. And as it hung there we four, forgetful for the moment of all else, were gazing down through the space-flier's window through that opening, down into the great more brightly-lit space that we could see beneath, beneath the huge metal shield that covered all this world!

The first thing that I noted, gazing downward, was that the space beneath the giant metal roof of Neptune was a great one, since it was a full mile from the opening in that roof to the surface of the world far below. Gazing down toward that surface, seeing at last the true surface of Neptune lying in the brighter light that existed in some strange way beneath the gigantic metal roof, we gasped. For upon that surface there loomed countless strange structures such as we had never seen before. Rectangular in shape were those structures, with straight black walls, of great size but seeming rather low in height, and they were without exception roofless! In them we could dimly make out from our great height the gleaming shapes of what seemed huge machines of one sort or another, but could not at that height see whether living beings of any sort moved among the structures. The great circle of the world beneath that we could see, hanging above the opening, was completely covered with these structures, the black walls of one roofless building being surrounded on all sides by the walls of others, there being no streets or open spaces whatever between them! It was as though, indeed, all the surface of the great world beneath had been divided into great compartments by a great checkerboard arrangement of intersecting black walls!

Marlin's eyes were gleaming with excitement as he gazed down. "The city of the creatures of Neptune!" he breathed, as in awe we four stared down. "The city of Neptune that lies beneath the colossal roof, and that must hold somewhere that which we have come to seek!"

"You're going to venture down into this city—down under the great roof?" I asked, and he nodded.

"We must, Hunt, to find the giant force-ray's source. But stand ready to flash the space-flier back upward—for if we're discovered by whatever beings inhabit this strange world, I think we'll get short shrift!"

A moment we paused there, and then as my hands moved upon the switch-controls, decreasing the power of the force-ray that held us upward the space-flier was sinking smoothly and slowly downward, down through the great opening! Tensely and with fascinated interest we gazed about now as we sank into the great space that lay beneath the huge metal roof. That space was brighter-lit than above the roof, we saw, and as we turned a moment to glance upward we saw that looking upwards, the roof was perfectly transparent! Dark, opaque metal when seen from above, it was almost invisible in its transparency when seen from below! And, seeing that, we understood the great roof's purpose. It had been constructed and placed above all Neptune, encircling the great planet and enclosing it, to retain that planet's heat as much as possible. For it was apparent that heat and light radiations or vibrations could not pass up through the metal of the roof from beneath, making it appear black and perfectly opaque from above, but could pass freely down through it from above, making it appear almost perfectly transparent from below!

Even as we grasped the wonder of that, though, we had forgotten it, in the greater wonder of the things that lay now before our eyes. For as we sank down in our space-flier into the great space beneath that roof we could see the surface of great Neptune itself, stretching far away beneath that mighty enclosing shield above it, and covered to the horizons by the strange rectangular and roofless structures such as we had already seen. These were formed, indeed, by smooth black walls of some two hundred feet in height that ran in straight lines in checkerboard arrangement across all the surface of this huge planet, apparently, forming upon all its surface, without streets or parks or openings of any kind, a vast city of rectangular compartments, large and small! A titanic streetless city that covered apparently all the surface of giant Neptune!

But most wonderful of all the things that lay before us in that moment was the fact that nowhere about us could we see any sign of supporting pillars or piers for the giant roof that stretched far above us! For though we could gaze far away to the distant horizons of this great world, we could find no single support for that huge metal roof that apparently covered all the great planet, and whose weight must have been incalculable! And another feature of the giant roof puzzled us. It puzzled us to see the great openings in it like that down which we had come, great circular openings which we could see in it here and there at great distances from each other. Those openings were provided on their under-side with great sliding shutters for closing them tightly, yet all were open! Why should they be open, we silently asked ourselves, if the purpose of the roof was to retain Neptune's heat within that roof? For the existence of those great and unclosed openings in the roof must surely be defeating that purpose, for our outside-temperature dial recorded the same zero temperature as prevailed above the roof!

Yet even these strange things could not wholly draw our interest and attention from the strange compartment-city beneath, as our space-flier sank toward it. We were within a few hundred feet of it, now, and as we dropped nearer, Marlin and Whitely and Randall staring eagerly down beside me, my hands were tense upon the switch-controls, ready to send our flier leaping instantly upward. For if the beings of the city beneath, whatever their nature, caught sight of us, we could expect nothing but instant attack. So that a tenseness held all of us as our great flier's faceted polyhedron dropped on through the pale light beneath the great roof toward the black-walled, checkerboard-like city that stretched across the surface of the great world beneath us. And now, as we sank lower, our eyes were making out ever more clearly the details of that amazing city.

The rectangular black-walled compartments held, as we had half-realized from above, various strange-shaped mechanisms and objects which we could even now only vaguely discern. We could see clearly, though, that here and there across all the vast city's compartmented surface there stood giant metal globes, each a hundred feet in diameter and each occupying a square compartment of its own. There seemed hundreds of these great gleaming globes, scattered here and there in compartments across the city's surface as far as we could see, though their purpose was then quite incomprehensible to us. But as we sank lower still, ever more cautiously, it was not the globes or the compartments' contents that held our attention so much as the astounding, stupefying fact that now was thrust upon us—namely that in all the gigantic compartmented city, in all its strange great black-walled rectangular and roofless enclosures, there moved no living being!

"Dead!" Randall's cry expressed in that instant the stupefaction of all of us. "A dead world!"

"Neptune—a dead world!"

A dead world! For truly it seemed a dead world that lay there in the dim pale light beneath us! A world whose strange contiguous compartments stretched away from horizon to horizon to form the colossal city above which we hovered, but a world, a city, in which was no single discernible thing of life! The endless black-walled compartments, the strange-shaped structures and mechanisms, the great enigmatic globes—all these things lay beneath us in a silence and a death that were stunning to our senses! Lay beneath us as though death had reached out of the unknown to annihilate suddenly all living things upon this alien world, leaving in it only the cold and the silence and the death that enwrapped it now! Neptune—we had flown across the awful void toward it for week upon week, prepared to find within it any strange beings, any alien and terrible form of life, but never had we been prepared to find it without any life whatever—an utterly lifeless world!

As we stared down toward it in utter silence it seemed to me that my brain was spinning from the stupefying shock of amazement that was ours. For if the world beneath us was truly a dead one, if Neptune lay now without life, its colossal compartment-city entirely lifeless, whence came that giant force-ray that was stabbing across the solar system from Neptune to turn the sun ever faster toward its division? Whence came that doom which was being loosed upon our Earth and upon all the solar system, almost, by that gigantic ray? Was that great ray, after all, only some incomprehensible freak of natural forces, impossible to withstand, and had Neptune, once the home of some alien, mighty civilization, lain for eons in silence and death? Had our desperate mission which alone held a chance for Earth, our terrific race out through the unthinkable reaches of the solar system's spaces toward its outermost planet, been in vain?

Marlin must have felt something of the same despair in that moment, but his strong face betrayed no trace of it as he turned to us. "It's evident that this vast compartment-city, this whole world, perhaps, is deserted," he said. "But where does the great ray come from?"

Whitely shook his head, glancing at his instruments. "Impossible to say," he said. "The recording-instruments here show only that we are close to the great ray's source, that that source is in the region around Neptune. But the emanations or reflections from it striking the instruments are so powerful as to make it impossible to determine the ray's source exactly."

"But the city beneath!" I cried. "Even if it is dead, deserted, we might be able to find in it some clue to what has happened here, some idea of what manner of creatures the Neptunians were, and perhaps some clue to the great ray's source!"

Marlin pondered, then nodded. "Hunt's right," he said. "If we explore this deserted compartment-city beneath we may find some suggestion that will lead us to the great ray's source. And we must find out soon, for only eighty-five days are left before the sun divides into a double star and dooms Earth!"

"But we shouldn't risk all of us on this venture," I said. "The safest way would be to keep the space-flier, with two of us inside, hovering here above the city while the other two go down to it and explore it in their space-walkers."

This we finally agreed to do, and Marlin and I insisted upon being the two to make the venture, Whitely and Randall reluctantly agreeing at last to remain within the space-flier, watching and waiting for us. So, bringing the space-flier down to a height of a thousand feet above the compartmented city, I set the force-ray to hold it motionless there, Randall taking my place at its controls. Then Marlin and I were quickly getting into our two cylindrical space-walkers. Once inside them, we each gripped in a great pincer-hand the pointed bars of steel that we were to take with us, and then unscrewed the inner door and passed into the vestibule-chamber. Another moment and with the inner door closed, the outer one was swinging open, and the denser and colder air from without was rushing into the vestibule-chamber. We did not feel its cold, however, snug in the insulated and heated cylinders of the space-walkers, but drew ourselves to the outer door, turning on the force-rays from the bottoms of our cylinders. Then as we drew ourselves out through the door and into empty air, we were both sinking gently downward, our fall slowed to a mere floating drop by the down-pressing power of our force-rays.

Down through the dim pale light of Neptune's day we sank, down until just beneath us lay one of the intersecting black walls. As I saw this I shot my supporting force-ray outward at a slant, and as this sent me down obliquely, I floated down past that wall, Marlin doing the same beside me, and in another moment we had come gently to rest just above the black smooth floor of one of the great compartments, the force-rays from the bottoms of our space-walkers holding us a foot or so above the floor. Resting there, Marlin and I looked up first. Beside us towered the black two-hundred foot wall of the compartment, and far above we could make out the hovering space-flier, its great gleaming polyhedron hanging motionless and watchful above. We waved the great metal arms of our space-walkers toward it, toward Whitely and Randall inside it, and then turned to examine the place in which we stood.

It was an oblong compartment some four hundred feet in length, and half that in width, its great black walls towering on all sides of us. Ranged around the compartment against those walls were rows of strange squat mechanisms of a roughly pear-like form, that loomed each a score of feet in height. Marlin and I shot our space-walkers toward the nearest of these mechanisms, to examine it. We saw that in the top of it was an odd cone-like opening, and that there ran out of the gleaming metal cover of the thing a thick pipe or tube that connected with a larger pipe that encircled the compartment, connected to each of the mechanisms. Then as we reached forward, swung aside the metal cover of the mechanism, exposing an intricate system of sections inside it through which ran slender tubes acted upon by what seemed projectors of electro-magnetic force about them, Marlin pointed toward them, leaned toward me until his space-walker touched mine and spoke to me through the touching metal.

"A water-making mechanism this seems to be, Hunt," he said. "In some way it must draw down ceaseless supplies of hydrogen and oxygen atoms from the great vapor-masses above the roof, and then recombine them here into water."

I nodded, gazing at the thing. "But it hasn't been used for years—for centuries, perhaps," I said. "Look—that dust upon it——"

For upon the pear-shaped mechanism before us, and on all those others and all other things about us, there rested a coating of fine dust that was inches thick, a dust-coating that we knew only a great period of time could have deposited there. A moment we stared at that, two grotesque figures there in the great cylinders of our space-walkers, and then were moving on, along the wall. That black smooth wall, we saw now, was composed of a material that looked much like a black seamless stone, but one that seemed diamond-hard. For our pointed steel bars could make not the slightest impression upon it, and it was evident, from the monolithic construction of the great walls about us and of the smooth black paving upon which we walked, that this diamond-like smooth stone had been artificially made. Later we were to learn that it was constructed by a building up of molecules into a deliberate crystalline formation that far exceeded the strength and stability of any other material's crystalline structure, and thus gave to the black artificial stone a diamond-like hardness and a tensile strength exceeding that of steel.

Around the great compartment we walked, our eyes ranging over the great pear-shaped mechanisms and the great pipes connecting them, and then Marlin and I stopped short. For there in the black wall before us was a door, an opening that connected with the adjoining compartment on that side. It was by means of doors like that, it was plain, that the necessity of streets in this compartment-city had been obviated, making it possible to pass across the city through the compartments themselves if needed. Yet it was in stupefying surprise that Marlin and I now gazed toward that door. For it was all of six feet in width, but hardly more than four feet in height! Its opening stretched there in the black wall as though an ordinary door-opening of one of Earth's buildings had been set in that wall sidewise! And as we looked stunnedly about we saw that all the doors set in the compartment's four walls were of the same size and shape!

"Those doors!" I cried to Marlin, leaning beside me. "Those were never made for human beings or for near-human beings!"

"Then these Neptunians that once were here—" Marlin began, and then stopped; we gazed in silence at each other through the vision-windows of our space-walkers.

And silence seemed oppressive all about us then, a silence that lay as thickly over the deserted compartment-city as the thick dust of unguessable years that covered it. A chill seemed to have struck home to us in some strange fashion with the discovery of those grotesque door-openings and their significance. I glanced upward, saw that the faceted ball of the space-flier was still hanging motionless high above, and then as I turned back saw that Marlin had moved toward the low door toward which we had been gazing. A moment he contemplated it, then motioned to me with the big metal arm of his space-walker, and as I came to his side, grasped that door's edge with his great arms and lowered his space-walker's big cylinder until it lay on its side on the smooth black paving. Then he was drawing it through the door, aiding himself with a force-ray shot from the opening in its bottom toward the compartment's opposite wall behind us. When he was through, he drew himself erect, and in a moment I had followed him and was standing with him in the next compartment.

That second compartment, we found, was a replica of the first, being of the same size and holding within it several dozen more of the pear-shaped water-manufacturing mechanisms. We passed through it, therefore, over the dust-strewn paving and through the low similar door on its opposite side, to find ourselves in still another compartment of water-manufacturers. Pressing on, rapidly becoming able to pass through the low strange doors easily in our cumbrous space-walkers, we passed through a half-score more of similar compartments all holding only the dust-covered, pear-shaped water-mechanisms, and then at last we passed into a different compartment, one that held a strange shelving that covered all its walls, at which we stared in perplexity for some time.

This shelving consisted of horizontal and perpendicular shelves of smooth black stone like that of the walls themselves, running along and up and down those walls and forming thus a continuous series of box-like openings, each some four feet in length and two in height. There were hundreds of these shelves in the compartment, we could see, yet all of them were quite empty, and in the compartment there seemed to be no other object. They suggested the equipment of a store-room, yet there was no faintest clue as to what had been stored in those shelf-tiers of openings, ranged one above the other all around the walls. Had Marlin and I been able to guess the astounding truth as to those tiers of compartments as to their significance and purpose, much would have been clear to us right then. As it was, after vainly endeavoring to fathom the purpose of the things, we gave it up and moved on out of the compartment, and through similar shelf-tiered compartments beyond it.

By this time we had passed some distance from beneath our hovering space-flier, but still could see its gleaming polyhedron hanging high in the air behind us. Reassured by the sight of it, we passed on, and in the next half-hour progressed through many more compartments. Some of these contained water-manufacturing mechanisms or tiers of strange shelf-openings such as we had already seen. But many others held mechanisms or objects strange to our eyes, before which Marlin and I stood entranced. We almost forgot, in the overpowering interest of the things that we found in those compartments, the object of our exploring search through the strange compartment-city, our search for clues as to the beings of Neptune and as to the great force-ray that was turning the sun ever faster.

Compartments we found in which were structures that puzzled us as completely as had the tiers of shelf-openings. These structures were great flat metal containers, each scores of feet in length and width but hardly more than a foot or two in depth. They were ranged one above the other in great supporting frameworks, and each container was filled with black fine soil. The compartments that held these had set in their walls great white disks which were connected to intricate apparatus that seemed generators of some kind of force, but more than that we could not ascertain from our inspection of them. The whole arrangement, the great shallow containers of soil, the disks in the walls, the generators connected to them—all was utterly enigmatic and perplexing to us, and we were forced to give up the riddles and pass on into other compartments, in which were other things almost as mysterious.

Some held giant globes of burnished metal, now dust-covered, which occupied almost a whole compartment each. These great gleaming globes were among the most puzzling things we had found, since there was, in the compartment of each one, no other object or indication of their purpose, save for a few switches mounted upon a panel, the combination of which we could not discover, opening and closing them in vain. We had seen these great globes from above, dotting the vast compartment-city here and there in great numbers, but we could learn no more of their purpose standing there beside them than we had been able to guess from above. And near these there were strange looming machines, many-cogged and with a great hopper above whose purpose we guessed, at least, guessing that these were the mechanisms that produced from some raw materials the artificial diamond-hard black stone-material that made up all the intersecting walls of this strange huge city-world.

Each of these machines had before it a very low, round metal seat, with in front of that seat the controls of the machine, a half-dozen burnished metal levers. As we saw them Marlin and I exchanged startled glances. Had the being who operated that machine, who sat before it, held and operated all those control-levers of the mechanism? Back to our minds flashed the strange low openings of the doors through which we had come, and for a moment the same strange sense of dread chilled me. But I shook off the feeling, followed Marlin on into another compartment, glancing back through to where our space-flier poised in the air now far across the city behind us.

It was into another long rectangular compartment that we passed, one that held, like that out of which we had just come, rows of strange many-cogged mechanisms. But one feature of that compartment caught our attention instantly, held us motionless and staring. And that was that those rows of great mechanisms were not complete! Here and there in those rows were gaps, as though machines had been removed from the compartment, and where those gaps were, where the missing machines had stood, were squares on the floor where their bases had rested, squares that were entirely free of the inch-thick dust that lay over all else! And even as we stared, as we comprehended the astounding significance of that, we saw that upon the dust-coated floor before us were many tracks, small round and strange tracks in the thick dust that were of great number and that had been made, it was apparent from their dust-free condition, but days or hours before!

"Marlin!" I whispered, grasping my companion's space-walker with the great metal arm of my own and touching head casing to head casing. "Marlin—those tracks—someone, something has been here—and but recently!"

"It can't be!" he exclaimed, his voice hushed strangely like my own. "Neptune—all this great compartment-city—it's all dead, deserted——"

"But those tracks!" I insisted. "Those squares in the dust—something's been here and has taken a half-dozen of these great machines away with them! And we know that something on Neptune is sending the great force-ray out to the sun!"

"It can't be," Marlin repeated. "We found no source of the great ray on Neptune's sunward side, and, too, how can that ray shoot always toward the sun from some spot on Neptune when Neptune itself is constantly turning? No, Hunt, I think that this means—but look up there!"

As he cried out he was gazing suddenly upward, his space-walker's great arms pointing up, and at that horror-stricken cry, I glanced up to see a sight that froze me motionless there in astonishment. For there, high above us and above the great compartment-city, a dozen strange great shapes were dropping down through the air toward us, were dropping down through one of the openings in the great roof! Long great cylinders of gleaming metal those shapes seemed, dropping silently and smoothly down from the opening, toward the compartment-city, but even as we looked in amazement and terror up toward them, they had halted in mid-air, as though seeing the faceted ball of our hovering space-flier hanging above the city far behind us. Then the next instant all the dozen great cylinders were flashing with unbelievable speed toward our space-flier, a half-score narrow, pencil-like rays of pale, almost invisible light or force stabbing ahead of them toward the space-flier!

Marlin and I cried out in the same instant as those great cylinders whirled through the air toward the space-flier, and in that moment it seemed to us that our wild cries had been heard, for we saw the space-flier whirl itself to one side suddenly, as though Randall and Whitely in it had caught sight suddenly of that onrushing menace. The pale, almost unseen stabbing little rays of force or light shot past them as they swerved thus, and then the next moment cylinders and space-flier seemed to be whirling in a wild melange of geometrical metal forms there in the pale dim light above the great compartment-city. We saw the slender, pencil-like shafts of force stabbing this way and that, saw one cylinder, struck by the shafts of its fellows, riven asunder by those shafts as though by swords of steel and then suddenly the gleaming polyhedron of the space-flier had plunged up out of the wild mêlée and was rocketing up toward one of the great openings in the vast roof above!

As Whitely and Randall thus whirled the space-flier up in an effort to escape their outnumbering, unknown attackers, we saw three of the great cylinders rushing up after them. In another moment the space-flier, closely followed by its three pursuers, had rushed up through the opening and disappeared above, and as they did so we saw that the remaining eight cylinders were dropping now again toward the compartment-city! Watching stupefied still in our amazement, Marlin and I saw that four of the cylinders were heading down toward a point in the great city somewhat to the right of us, while the other four were slanting down now almost straight toward the compartment in which we stood! And as I saw that, as I saw and understood the significance of the tracks and missing mechanisms in this compartment, I grasped Marlin's great metal arm with one of my own, again touching head-armors.

"They're coming down to this compartment!" I cried. "It was they who took the missing mechanisms from here—they've come for more!"

"Out of the compartment, then!" Marlin shouted. "They're after Whitely and Randall in the flier, and if they find us here——!"

With the words we were throwing ourselves, prisoned in our great cumbrous space-walkers as we were, toward the low door through which we had come. In a moment we were through that door, were in the adjoining compartment, but hardly had we gained it than there swept through the pale light from high above four great cylindrical shapes, slanting smoothly down toward the compartment we had just left! From above they could see us easily, whatever beings were inside those descending cylinders, so that as they shot down over our roofless great compartment, Marlin and I poised motionless, praying that our great gleaming space-walkers might be mistaken for mechanisms. Far across the compartment-city we could glimpse the four other cylinders dropping down toward a different point, also, and then in the next moment the four above us had shot down over us and with a throbbing sound coming clearly to us from those cylinders' interiors, were coming to rest in the compartment we had just left!

Glancing for a moment at each other through the vision-windows of our space-walkers, Marlin and I then softly moved in them toward the low door through which we had just come. For though our fear was great, our curiosity, our realization of the mission that had brought us out here to Neptune, was greater. In a moment we were at the door, were lowering ourselves awkwardly and silently to a position from which we could gaze through it into the adjoining compartment. In that compartment, we saw now, the four great cylinders had landed, and were resting upon the floor at its center. Each cylinder was of forty feet diameter and twice that in height, and their gleaming metal sides were broken here and there by small windows. They were broken too, we saw with a start, by ray-openings like those of our own space-flier, and it was evident from those that the cylinders were propelled through space by the same force-rays that moved our flier!

Before we could fully comprehend the meaning of that fact, though, there came a low clanking of metal and before our eyes a section in each of the curving sides of the cylinders, near the base of each, was abruptly sliding aside, leaving in the metal wall of each cylinder a low oblong door-opening like those of the compartments about us. Now we heard from inside that opening a stir of movement, and saw vaguely a shape or shapes that moved in the cylinder's dark interior. Then, as we gazed with tense nerves toward that opening, there moved out of the cylinder's dark interior through that opening, into the pale dim light of the Neptunian day, a creature at which Marlin and I stared in that moment with horror-stunned minds! A being so grotesque and so awful in appearance that for the moment it seemed to me that it needs must be a creation only of our over-strained nerves and brains!

It was a creature that bore no conceivable resemblance to the human form or to any other in our knowledge. The body was a great flat disk of pale-green flesh, five feet in diameter and hardly a foot in thickness. It was supported in a flat or horizontal position above the ground by seven short thick limbs of muscle or flesh, which were each three feet in length and which projected down from the big disk-body at equal intervals around its circle. The only visible features of the creature were the eyes and mouth. The eyes were two in number, and were set close together in the edge of the disk-body. They were like the eyes of some insect, being each inches across and bulging outward, being composed each of a myriad smaller glistening lens-divisions, like the eye of a fly! And as I saw with shuddering horror those two bulging strange eyes gazing about, it came to me that it was only by means of such great, powerful eyes and their many lenses that any creature here in the dim light of Neptune could see clearly all things about it!

The mouth was a white-lipped circular opening, and was set at the very center of the horizontal disk-body's upper surface! No stranger combination can be imagined than that which presented itself thus in the appearance of that creature before us, with the two bulging glassy eyes staring forth from the edge of the great disk-body, and the round mouth gaping there in that disk-body's flat upper surface. Slung around the disk-body the creature wore a flexible armor or dress of connected straps of flexible metal. In a loop of this rested a metal tube formed by the joining together of two tubes of dissimilar thickness. And attached to the flexible straps in another position, at the disk-body's edge, was one of the strangest features of its appearance, a small metal ball that seemed glowing with unceasing radiant light!

The creature gazed about him, unaware of our awe-stricken gaze, and then half-turned and seemed to call to others in the cylinder from which he had emerged, a strange sound issuing from his mouth-opening. That sound was like a swift succession of staccato snaps of sound, as clear and sharp as the snap of metal on metal. From the variation in their utterance, though they were in a single pitch only, it was evident that they formed the speech of the strange creature, and as he gave utterance to them, others like him, other similar disk-bodied green beings, were emerging from the cylinder behind him and from the other cylinders. In a moment a score or more were gathered there, moving toward the great cogged mechanisms beside them, and as they did so the staccato snapping of their strange speech came loud to our ears. And as they did so, too, we saw that the seven strange limbs of each of them served him as arms as well as supporting legs, since some used some of those limbs to carry tools, holding them tightly in fingerless, muscled grasp!

"Neptunians!" whispered Marlin beside me. "Neptunians, Hunt—those squat, flat disk-bodies—those great eyes——!"

Neptunians! Yet I had seen myself that they must be so, that only on a great planet like Neptune, with far greater gravitational power than Earth, could those squat, flat bodies have evolved. For the greater the power of a planet's gravitation, the lower and the more squat will be the forms of life that evolve upon it. And just as these Neptunians had evolved in their strange disk-form here on the great planet, due to its greater gravitational power, so had their great light-gathering eyes been evolved by the dimness that reigned here always. And it was these beings, it was clear, who had built the vast compartment-city that covered all of the great planet's surface about us, since it was only beings like these who would have built such strange, low doors in it for their own flat disk-bodies, only such beings as these who, with their seven great limbs, could manipulate the controls of the mechanisms we had seen!

"Neptunians!" I whispered it, myself. "But if it's beings like these who inhabit Neptune, who have sent the great force-ray stabbing toward the sun to divide it, where are they all? Why have they left all this city, all this world, dead and deserted?"

Marlin, inside his space-walker, shook his head. "God knows, Hunt! If all these Neptunians have deserted their world, where have they gone? I know no more than you. But it's clear that they've come back for more of those great mechanisms."

It was, indeed, evident that that was the object of the Neptunians' visit to the compartment-city, for now the score or more in the adjoining compartment were busily working with their tools upon three or four of the great cogged mechanisms that loomed there. Swiftly they were taking down those mechanisms, were dissembling them into a myriad intricate parts which were stowed away in the four great cylinders. More than once some of them passed close to the low door through which Marlin and I were gazing, but none ventured through it into the compartment in which we hid, seeming all to be intent upon the business at hand. And as they worked on we began to understand some of the features about them that had puzzled us in our first horror-stricken sight of them.

We had been puzzled, indeed, that they were able thus to move about unheedingly without protection of any sort in the zero-cold that reigned about us. But now as one or two of them passed close to the door by which we crouched, I gazed closely at the glowing little ball that each had attached to his metal armor, and guessed then what I was later to learn was the truth, that that ball was glowing with radiant heat and had the power of heating to comfortable temperature the atmosphere for a few feet directly around its wearer. Thus the wearer of it moved always in a little volume of warm air, though the air outside that area might be at zero temperature. And thus it was that the Neptunians were able to withstand the bitter cold about us, from which we were protected by our space-walkers.