Even to an Earth man, Mars is not a world to promote enthusiasm. It is rather cold at the best of times, much too dry, and woefully lacking in air — breathable or otherwise. The first and last of these points struck Ken most forcibly.
The landscape in front of him was very flat. It was also very patchy. In some spots bare rock showed, but those were few and far between. Much of the area seemed to be dark, naked soil, with bits of green, brown, red and yellow mingling in the general background. Nearly half of the landscape seemed to be composed of the patches of white, which had seemed to be a solid mass from space. Probably, Ken realized, they formed a solid covering closer to the center of the white region; they had landed on its edge, as planned.
He took a careful step away from the ship’s side. The gravity was less than that of Sarr, but distinctly greater than on Mercury, and the armor was a severe burden. The two tentacles inside his right “sleeve” forced the clumsy pipe of steel downward almost to the ground, and manipulated the handlers at the end. With some difficulty, he scraped loose a piece of dark brown soil and raised it to eye level. He locked the “knees” of the armor and settled back on the tail-like prop that extended from the rear of the metal trunk, so that he could give all his attention to examining the specimen.
The glass of his face plate showed no signs of differential contraction so far, but he carefully avoided letting the soil touch it during the examination. He almost forgot this precaution, however, when he saw the tiny varicolored objects on the surface of the sample. Weird as they were in shape, they were unquestionably plants — tiny, oddly soft-looking compared to the crystalline growths of Sarr, but still plants. And they lived in this frightful cold! Already those nearest the metal of his handler were shrivelling and curling, cold as the outside of his armor, already must be. Eagerly Ken reported this to the listeners inside.
“This life must have something in common with that of Three,” he added. “Both must run on chemical energy of the same general sort, since there’s no important difference in their temperatures. This soil must have all the elements necessary, even if the compounds aren’t quite right for what we want — who ever heard of a life form that didn’t have a good deal of latitude that way?” He looked back at the sample he was holding. “It looks a little different around the edges, as though the heat of my armor were making some change in it. You may be right, Drai— there may be some volatile substance in this soil that’s evaporating now. I wonder if I can trap it?” He lapsed into thought, dropping his specimen.
“You can try afterward. Why not investigate the white patches?” called Drai. “And the rocks, too; they might be something familiar — and soils are made from rock, after all.” Ken admitted the justice of this, hitched himself off the rear prop, unlocked his leg joints, and resumed his walk away from the ship.
So far, he had felt no sign of cold, even in his feet. Evidently the soil was not a very good conductor of heat. That was not too surprising, but Ken made a mental note to be careful of any patches of solid rock he might encounter.
The nearest of the white areas was perhaps thirty yards from the airlock door. Reaching it quickly enough in spite of the weight of his armor, Ken looked it over carefully. He could not bend over to examine its texture, and was a little uneasy about picking it up; but remembering that the handlers of his armor extended some distance beyond the actual tips of his tentacles, as well as the fact that the first sample had been harmless, he reached down and attempted to scrape up a piece.
This seemed easy enough. The handler grated across the surface, leaving a brown streak behind — evidently the white material formed a very thin layer on the ground. Raising the sample to eye level, however, Ken discovered that he had nothing but dark-colored sand.
Excusably puzzled, he repeated the process, and this time was quick enough to see the last of the white material vanish from the sand grains. “You were right, Laj,” he said into his transmitter. “There’s something here that’s really volatile. I haven’t got enough for a good look, yet — I’ll try to find a deeper deposit.” He started forward again, toward the center of the white patch.
The expanse was perhaps fifty yards across, and Ken judged that the volatile coating might be thicker in the center. This proved to be the case, but it never became heavy enough to impede even his progress. His trail was clearly marked by bare soil, as the stuff faded eerily out of sight around each footprint. Ken, though he could have looked behind in his armor without turning his whole body, did not notice this, but the watchers from the ship did. Drai remarked on it over the radio, and Ken responded:
“Tell me if it stops — maybe that will be a place where it’s thick enough to pick some of the stuff up. I’d like to get a close look at it before it evaporates. Right now, I can’t imagine what it might be, and I need information badly in order to make even an educated guess.”
“The trail is getting narrower now — there are separate spots which outline the shape of the feet of your armor, instead of broad circular areas that blend into each other. A little farther ought to do it.”
A little farther did. Ken was not quite to the center of the white patch when Drai reported that he had ceased to leave a trail. He promptly stopped, propped himself as he had before, and scooped up a fresh handful of the evanescent substance. This time there was practically no sand included; the material was fully an inch deep. The mass on his handler began to shrink at once, but not so rapidly as to prevent his getting a fairly long look. It was crystalline, millions of minute facets catching and scattering the feeble sunlight; but the individual crystals were too tiny to permit him to determine their shape. It was gone before he was really satisfied, but there seemed little likelihood of his getting a better look. Somehow a sample would have to be obtained — and analyzed. He thought he saw how that might be done, but some careful preparation would be necessary. Announcing this fact over his suit radio, he prepared to return to the ship.
Perhaps, in the half-seated attitude he had been holding, his feet had been partly out of contact with the armor; perhaps in his single-minded interest in things outside he simply had not noticed what was happening. Whatever the cause, it was not until he stood up that the abrupt, stabbing blade of cold seared straight from his feet to his brain. For an instant he settled back on his prop, trying to draw his feet from the biting touch of what was supposed to be insulation; then, realizing that matters would only grow worse if he delayed, he forced himself into action. Barely able to bite back a scream of anguish, he strained every muscle forcing the unwieldy mass of metal toward the air lock; and even through his pain, the thought came driving — no wonder the trail had become narrower; the feet of his armor must be nearly at the temperature of their surroundings. From five hundred degrees above zero Centigrade to fifty below is quite a temperature gradient for a scant three inches of steel, vacuum space, fluid coils, and insulating fiber to maintain, even with a powerful heating coil backing up the high-temperature side of the barrier.
The pain grew less as he struggled toward the lock, but the fact did not make him any happier; it terrified him. If he should lose control of his feet, he would die within sight of the Karella’s crew, for there was not another suit of special armor aboard that could be worn to rescue him.
Now his face was cold, too — he must be losing radiation even through the special glass of the face plate. His tentacle tips were feeling the chill, but not so badly; the fact that the deadly whiteness had touched only the handlers, inches beyond the “inhabited” parts of the sleeve, was helping there. He had reached the edge of the area of death, and only thirty yards of bare ground lay between him and the lock. That ground was cold, too. It must be as cold as the other area; but at least it did not seem to drink heat. The lock door was open as he had left it, a metal-lined cavern that seemed to draw away as he struggled forward. He was numb below the lower knees, now; for the first time he blessed the clumsy stiffness of the armor legs, which made them feel and act like stilts, for that was all that enabled him to control the feet. Once he stumbled, and had time to wonder if he would ever be able to get the clumsy bulk erect again; then he had caught himself in some way — he never learned how, and no one on the ship could tell him — and was reeling forward again. Ten yards to go — five — two — and he brought up against the hull of the Karella with a clang. One more step and he was inside the lock. Two, and he was out of the swing of the massive door. With frantic haste he swung the sleeve of his armor at the closing switch. He hit it — hit it hard enough to bend the toggle, but the circuit was closed and the door thudded shut behind him, the sound of its closing coming through the metal of floor and suit. Then came the air, automatically, pouring into the lock chamber, condensing on the body of his armor, freezing into a yellow crust on the extremities. With the pressure up, the inner door swung wide, revealing Drai and Ordon Lee in the corridor beyond. The former shrank from the fierce chill that poured from the chamber; the pilot, thinking faster, leaped to a locker nearby and seized a welding torch. Playing the flame of this ahead of him, he approached Ken carefully.
The crust of sulfur boiled away instantly in the flame, to be replaced almost as fast when the tongue of light swung elsewhere. Long seconds passed before the metal was warm enough to stay clear, and more before it could be touched, and the almost unconscious Ken extracted. Minutes more passed before the throbbing agony receded from his limbs, and he was able to talk coherently, but at last he was satisfied that no permanent damage had been done. He had not actually been frost-bitten, though judging by the color of his skin he had come dangerously near to it.
Drai and Lee, amazed and horrified at the results of the brief sortie, felt both emotions redoubled as they heard of his plans for another. Even Drai, interested as he was in obtaining useful information, made a half-hearted attempt to dissuade him from the project. Ken refused to be dissuaded, and his employer did not have too much difficulty in consoling himself — after all, it was Ken’s health.
The instructions to bring “whatever he thought he would need” had been obeyed, and Ken spent some time searching through the pile of apparatus from the Mercurian laboratory. What he found seemed to satisfy him, and he made a number of careful preparations which involved some very precise weighing. He then carried several items of equipment to the air lock, and finally donned the armor again, to Ordon Lee’s undisguised admiration.
From the control room port, Drai and the pilot watched Ken’s hasty trip back to the scene of his earlier trouble. He followed his earlier trail, which was still clearly visible, and carefully avoided touching the whiteness with any part of his armor. Arrived at the point where his cooling boots had been unable to boil their way down to solid ground, he stopped. The watchers were unable to make out his actions in detail, but apparently he set some object on the ground, and began rolling it about as the white substance evaporated from around it. Presently this ceased to happen, as its temperature fell to that of its surroundings; then Ken appeared to pick it up and separate it into two parts. Into one of these he scooped a quantity of the mysterious stuff, using an ordinary spoon. Then the two halves of the thing were fastened together again, and the scientist beat a hasty retreat toward the air lock.
Drai was promptly headed for the inner door of the chamber, expecting to see what was going on; but the portal remained closed. He heard the hissing of air as pressure was brought up, and then nothing. He waited for some minutes, wondering more and more, and finally went slowly back to the control room. He kept looking back as he went, but the valve remained sealed.
As he entered the control room, however, Lee had something to report.
“He’s pumping the lock down again,” the pilot said, gesturing to a flaring violet light on the board. Both Sarrians turned to the port of the side toward the airlock, Lee keeping one eye on the indicator that would tell them when the outer door opened. It flashed in a matter of seconds, and the watchers crowded eagerly against the transparent panel, expecting Ken’s armored figure to appear. Again, however, nothing seemed to happen.
“What in the Galaxy is the fellow up to?” Drai asked the world at large, after a minute or so. Lee treated the question as rhetorical, but did shift part of his attention back to the control board. Even here, however, fully five minutes passed without anything occurring; then the outer door closed again. Calling Drai’s attention to this, he looked expectantly at the pressure indicator, which obediently flashed a report of rising pressure. They waited no longer, but headed down the corridor side by side.
This time Ken appeared to have finished his work; the inner door was open when they reached it. He had not permitted his suit to get so cold this time, it seemed; only a light dew dimmed its polish. Within a minute or so Lee was able to help him emerge. He was wearing a satisfied expression, which did not escape the watchers.
“You found out what it was!” Drai stated, rather than asked.
“I found out something which will let me figure out what it is, very shortly,” replied Ken.
“But what did you do? Why did you go out twice?”
“You must have seen me putting a sample into the pressure bomb. I sealed it in, and brought it inside so it would all evaporate and so that the pressure gauge on the bomb would be at a temperature where I could trust it. I read the pressure at several temperatures, and weighed the bomb with the sample. I had already weighed it empty — or rather, with the near-vacuum this planet uses for air inside it. The second time I opened the door was to let off the sample, and to make a check at the same temperature with a sample of the planet’s air — after all, it must have contributed a little to the pressure the first time.”
“But what good would all that do?”
“Without going into a lot of detail, it enabled me to find out the molecular weight of the substance. I did not expect that to be very conclusive, but as it happened I think it will be; it’s so small that there aren’t many possible elements in it — certainly nothing above fluorine, and I think nothing above oxygen. I’ll concede that I may be off a unit or so in my determination, since the apparatus and observing conditions were not exactly ideal, but I don’t think it can be much worse than that.”
“But what is it?”
“The molecular weight? Between eighteen and nineteen, I got.”
“What has that weight, though?”
“Nothing at all common. I’ll have to look through the handbook, as I said. Only the very rarest elements are that light”
“If they’re so rare, maybe the stuff is not so important for life after all.” Ken looked at Drai to see if he were serious.
“In the first place,” he pointed out, seeing that the other had not been joking, “mere rarity doesn’t prove that life doesn’t need it. We use quite respectable quantities of fluorine in our bodies, not to mention zinc, arsenic and copper. This other form of life may well do the same. In the second place, just because an element is rare on Sarr doesn’t prove it would be so on Planet Three — it’s a much bigger world, and could easily have held considerable quantities of the lighter elements during its original formation, even if they had been there as uncombined gases.” The group had been walking toward Ken’s room, where he had stored most of his apparatus, as they talked. Reaching it at this point, they entered. Ken draped himself without apology on the only rack, and began to flip through the pages of the chemical handbook, in the section devoted to inorganic compounds. He realized that his mysterious substance could contain carbon, but it certainly could not contain more than one atom per molecule, so there was no danger of its being a really complex organic material.
There were, in fact, just eight elements likely to be present; and the laws of chemistry would put considerable restriction on the possible combinations of those eight. The lightest of these was hydrogen, of course; and to the hydrogen compounds Ken turned, since they came first in that section of the handbook.
Drai had moved to a position from which he could oversee the pages that Ken was reading; the less interested or less excitable Lee stayed near the door and waited silently. He was more prepared than his employer for a long wait while the scientist made his search; and he was correspondingly more surprised when Ken, almost as soon as he began reading, suddenly stiffened in a fashion which indicated he had found something of interest. Drai saw the action as well.
“What is it?” he asked at once. Both Ken and Lee realized that the “it” referred to the substance, not the cause of Ken’s interest; Drai assumed without thought that his scientist had found what he was seeking.
“Just a moment. There’s something that doesn’t quite agree — but the rest is too perfect — wait a minute—” Ken’s voice trailed off for a moment; then, “Of course. This is under normal pressure.” He looked up from the book.
“This appears to be the stuff — it’s almost completely unknown on Sarr, because of its low molecular weight— most of it must have escaped from the atmosphere eons ago, if it ever was present. According to this handbook, it should be liquid through quite a temperature range, but that’s under our atmospheric pressure. It’s quite reasonable that it should sublime the way it did in this vacuum.”
“But what is it?”
“One of the oxides of hydrogen — H2O, apparently. If it proves to be essential for the form of growth you’re interested in, we’re going to have a very interesting time handling it.”
“We have cargo shells that can be kept at outside conditions, and towed outside the ship,” Drai pointed out.
“I assumed you did,” replied Ken. “However, normal ‘outside’ conditions in the space near Planet One would almost certainly cause this stuff to volatilize just as it did from the comparatively faint heat radiating from my armor. Your shells will have to be sealed airtight, and you will, as I said, have an interesting time transferring their contents to any cave we may pick.”
Laj Drai looked startled for several seconds. Then he appeared to remember something, and his expression changed to one of satisfaction.
“Well,” he said, “I’m sure you’ll be able to figure that one out. That’s what scientists are for, aren’t they?” It was Ken’s turn to look startled, though he had known Drai long enough by this time to have expected something of the sort.
“Don’t you ever solve your own problems?” he asked, a trifle sourly. Drai nodded slowly.
“Yes, sometimes. I like to think them over for quite a while, though, and if they’re scientific ones I don’t have the knowledge to think with. That’s why I hire people like you and Feth. Thanks for reminding me — I do have a problem at the moment, on which I have spent a good deal of thought. If you’ll excuse me, I’ll attend to the finishing touches. You can stay here and work on this one.”
“There’s nothing more we can do on this planet for the present.”
“That I can believe. We’ll head back for Planet One and the rest of your laboratory facilities. Come on, Lee— we’ll leave the scientist to his science.”
Ken, unsuspicious by nature, did not even look up as the two left his room. He had just found ammonia on the list, and was wondering whether his measurement could have been far enough off to permit the true molecular weight to be only seventeen. Melting-point data finally reassured him. For safety’s sake, however, he went through all the hydrogen, lithium, beryllium, boron, nitrogen, and oxygen compounds that were listed in the handbook. The faint disturbance incident to the vessel’s takeoff did not bother him at all. The silent opening of his door made no impression on him, either.
In fact, the door had closed again with a crisp snap before anything outside the printed pages registered on his consciousness. Then a voice, coincident with the closing door, suddenly shattered the silence.
“Sallman Ken!” The mechanical speaker over the entrance boomed the words; the voice was that of Laj Drai. “I said when we parted a moment ago that I occasionally solve my own problems. Unfortunately, you have come to represent a problem. There seems to be only one solution which will not destroy your usefulness. In a way I regret to employ it, but you have really only your own unwarranted curiosity to thank. When you wake up, we will talk again — you can tell me what you think of our commercial product!” The voice ceased, with a click which indicated that the microphone had been switched off.
Ken, fully aroused, had dropped the book and risen to his feet — or rather, left his rack and floated away from the floor, since they were in weightless flight. His eyes roved rapidly to all quarters of the room in search of something that might furnish meaning to Drai’s rather ominous words. Several seconds passed before he saw it — a rectangular yellow brick, floating in the air near the door. For a moment he did not recognize it, and pushed against a wall to bring himself nearer to it; then, as he felt the chill emanating from the thing, he tried futilely to check his drift.
Already the brick was losing shape, its corners rounding with the heat and puffing off into vapor. It was frozen sulfur — harmless enough in itself if contact were avoided, but terrifying when considered with his background of knowledge and suspicion. With a frantic flailing of his tentacles, he managed to set up enough of an air current to cause the thing to drift out of his path; but an equally anxious look about the room for something which might serve as a gas mask disclosed nothing.
He found himself unable to take his eyes from the dwindling object, now a rather elongated ellipsoid. It continued to shrink remorselessly, and suddenly there was something else visible in the yellow — the end of a small white cylinder. As the last of the protective box vanished, this began to turn brown and then black over its entire surface, and a spherical cloud of smoke enveloped it. For an instant a wild hope flashed in Ken’s mind; the thing had to burn, and a fire will not maintain itself in weightless flight. It requires a forced draft. Perhaps this one would smother itself out — but the cloud of smoke continued to swell. Apparently the thing had been impregnated with chips of frozen air in anticipation of this situation.
Now the edges of the smoke cloud were becoming fuzzy and ill-defined as diffusion carried its particles through the room. Ken caught the first traces of a sweetish odor, and tried to hold his breath; but he was too late. The determination to make the effort was his last coherent thought.