Ken wasted no time donning his space suit and leaving the ship with the others. Once inside the station and out of the heavy garment, he hastened to the shop to see how far out the returning test suit was; then, satisfied with its progress as recorded there, he headed for the observatory to continue his conversation with Laj Drai. He met no one on the way. Lee had stayed on the ship, Feth had disappeared on some errand of his own the moment the lock had closed behind them, and the rest of the personnel kept pretty much to themselves anyway. Ken did not care this time whether or not he were seen, since he planned a perfectly above-board conversation.

He was interrupted, however, in planning just how to present his arguments, by the fact that the observatory door was locked.

It was the first time he had encountered a locked door in the station since his arrival, and it gave him to think furiously. He was morally certain that the trading torpedo had returned during the absence of the Karella, and that there was a load of tofacco somewhere around the building. If this were the only locked door — and it was, after all, the room Drai used as an office—

Ken pressed his body close to the door, trying to tell by sound whether anyone were in the room. He was not sure; and even if there were not, what could he do? A professional detective could probably have opened the door in a matter of seconds. Ken, however, was no professional; the door was definitely locked, as far as he was concerned. Apparently the only thing to do was seek Drai elsewhere.

He was ten yards down the ramp, out of sight of the observatory door, when he heard it open. Instantly he whirled on his toes and was walking back up the incline as though just arriving. Just as he reached the bend that hid the door from him he heard it close again; and an instant later he came face to face with Feth. The mechanic, for the first time since Ken had known him, looked restless and uneasy. He avoided Ken’s direct gaze, and wound the tip of one tentacle more tightly about a small object he was carrying, concealing it from view. He brushed past with a muttered greeting and vanished with remarkable speed around the turn of the ramp, making no answer to Ken’s query as to whether Drai were in the observatory.

Ken stared after him for seconds after he had disappeared. Feth had always been taciturn, but he had seemed friendly enough. Now it almost seemed as though he were angry at Ken’s presence.

With a sigh, the pro tem detective turned back up the ramp. It wouldn’t hurt to knock at the door, anyway. The only reason he hadn’t the first time was probably a subconscious hope that he would find Drai somewhere else, and feel free to investigate. Since his common sense told him he couldn’t investigate anyway, he knocked.

It was just as well he hadn’t made any amateur efforts at lock-picking, he decided as the door opened. Drai was there, apparently waiting for him. His face bore no recognizable expression; either whatever bothered Feth had not affected him, or he was a much better actor than the mechanic. Ken, feeling he knew Feth, inclined to the former view.

“I’m afraid I’m not convinced of the usability of any Sarrian soil,” Drai opened the conversation. “I agree that most of the substances present in it, as far as I know, could also be present at Planet Three’s temperature; but I’m not so sure the reverse is true. Mightn’t there be substances that would be solid or liquid at that temperature and gaseous at ours, so that they would be missing from any we brought from home?”

“I hadn’t thought of that,” Ken admitted. “The fact that I can’t think of any such substances doesn’t mean they don’t exist, either. I can skim through the handbook and see if there are any inorganic compounds that would behave that way, but even that might miss some — and if their life is at all analogous to ours, there are probably a couple of million organic compounds — for which we don’t have any catalogue. No, blast it, I guess you’re right; we’ll have to take the stuff from the planet itself.” He lapsed into silent thought, from which Drai finally aroused him.

“Do you really think you’re going to be able to get to the surface of that world?”

“I still can’t see why we shouldn’t,” replied Ken. “It seems to me that people have visited worse ones before, bad as that is. Feth is pessimistic about it, though, and I suppose he has more practical knowledge of the problem than I. We can make more definite plans in that direction when the suit comes back, which shouldn’t be long now. According to the instruments it started back a couple of hours ago.”

“That means nearly three days before you’re sure. There must be something else — say! You claim it’s the presence of a conducting atmosphere that makes the heat loss on Planet Three so great, don’t you?”

“Sure. You know as well as I that you can go out in an ordinary space suit light years from the nearest sun; radiation loss is easy to replace. Why?”

“I just thought — there are other planets in this system. If we could find an airless one roughly the same temperature as Three, we might get soil from that.”

“That’s an idea.” Ken was promptly lost in enthusiasm again. “As long as it’s cold enough, which is easy in this system — and Three has a satellite — you showed it to me. We can go there in no time in the Karella —and we could pick up that suit in space while we’re at it. Collect Feth, and let’s go!”

“I fear Feth will not be available for a while,” replied Drai. “Also,” he grimaced, “I have been on that satellite, and its soil is mostly pumice dust; it might have come straight from the Polar Desert on Sarr. We’d better consider the other possibilities before we take off. The trouble is, all we’ve ever noted about the other planets of the system is their motions. We wanted to avoid them, not visit them. I do remember, I think, that Five and Six do have atmospheres, which I suppose writes them off the list. You might see where Four is just now, will you? I assume you can interpret an ephemeris.”

Ken decided later that courtesy was really a superfluous facet of character. Had it not been for the requirements of courtesy he would not have bothered to make an answer to this suggestion, and had not most of his attention been concentrated on the answer he would never have made the serious error of walking over to the cabinet where the table in question was located, and reaching for it. He realized just as he touched the paper what he was doing, but with a stupendous effort of will he finished his assurance that he could read an ephemeris and completed the motion of obtaining the document. He felt, however, as though a laboratory vacuum pump had gone to work on his stomach as he turned back to his employer.

That individual was standing exactly where he had been, the expression on his face still inscrutable.

“I fear I must have done our friend Feth an injustice,” he remarked casually. “I was wondering how you had come to imply that a round trip to Sarr would take only a week. I realize of course that your discoveries were made quite accidentally, and that nothing was farther from your plans than vulgar spying; but the problem of what to do about your unfortunate knowledge remains. That will require a certain amount of thought. In the meantime, let us continue with the matter of Planet Four. Is it in a convenient position to visit, and could we as you suggested pick up the torpedo carrying your suit without going too far from course?”

Ken found himself completely at a loss. Drai’s apparently unperturbed blandness was the last attitude he expected under the circumstances. He could not believe that the other was really that indifferent; something unpleasant must be brewing between those steady eyes, but the face gave him no clue. As best he could he tried to match his employer’s attitude. With an effort he turned his attention to the ephemeris he was holding, found the proper terms, and indulged in some mental arithmetic.

“The planets are just about at right angles as seen from here,” he announced at length. “We’re just about between the sun and Three, as you know; Four is in the retrograde direction, roughly twice as far from us. Still, that shouldn’t mean anything to the Karella”

“True enough. Very well, we will take off in an hour. Get any equipment you think you will need on board before then — better use engineering armor for Planet Four, even if it doesn’t have air. You’ll have to point out where they are to whomever I get to help you.”

“How about Feth?” Ken had gotten the idea that the mechanic was in disgrace for betraying the secret of their location.

“He won’t be available for some time — he’s occupied. I’ll give you a man — you can be picking out what you want in the shop; I’ll send him there. One hour.” Laj Drai turned away, intimating that the interview was at an end.

The man he sent proved to be a fellow Ken had seen around, but had never spoken to. The present occasion did little to change that; he was almost as taciturn as Feth, and Ken never did learn his name. He did all he was asked in the way of moving material to the Karella, and then disappeared. The takeoff was on schedule.

Ordon Lee, who evidently had his orders, sent the vessel around the planet so rapidly that the acceleration needed to hug the curving surfaces exceeded that produced by the planet’s gravity; the world seemed to be above them, to the inhabitants of the ship. With the sun near the horizon behind and the glowing double spark of Earth rising ahead, however, he discontinued the radial acceleration and plunged straight away from the star. Under the terrific urge of the interstellar engines, the Earth-Luna system swelled into a pair of clearly marked discs in minutes. Lee applied his forces skillfully, bringing the vessel to a halt relative to’ the planet and half a million miles sunward of it. Drai gestured to Ken, indicating a control board similar to that in the shop.

“That’s tuned in to your torpedo; the screen at the right is a radar unit you can use to help find it. There’s a compass at the top of the panel, and this switch will cause the torpedo to emit a homing signal.” Ken silently placed himself at the controls, and got the feel of them in a few minutes. The compass gave rather indefinite readings at first because of the distance involved; but Lee was quickly able to reduce that, and in a quarter of an hour the still invisible projectile was only a dozen miles away. Ken had no difficulty in handling it from that point, and presently he and Drai left the control room and repaired to a cargo chamber in the Karella’s belly, where the torpedo was warming up.

This time it was the suit still clamped to the outside that took all their interest. The whole thing had been left at the bottom of the atmosphere for a full hour, and Ken felt that any serious faults should be apparent in that time. It was a little discouraging to note that air was condensing on the suit as well as the hull; if the heaters had been working properly, some sort of equilibrium should have been reached between the inner and outer layers of the armor during the few hours in space. More accurately, since an equilibrium had undoubtedly been reached, it should have been at a much higher temperature.

The trickling of liquid air did cease much sooner on the armor, however, and Ken still had some hope when he was finally able to unclamp the garment and take it in for closer examination.

The outer surface of the metal had changed color. That was the first and most obvious fact. Instead of the silvery sheen of polished steel, there was a definitely bluish tint on certain areas, mostly near the tips of the armlike handling extensions and the inner surfaces of the legs. Ken was willing to write off the color as a corrosion film caused by the oxygen, but could not account for its unequal distribution. With some trepidation he opened the body section of the massive suit, and reached inside.

It was cold. Too cold for comfort. The heating coils might have been able to overcome that, but they were not working. The recorder showed a few inches of tape — it had been started automatically by a circuit which ran from a pressure gauge in the torpedo through one of the suit radio jacks as soon as atmospheric pressure had been detectable — and that tape showed a clear story. Temperature and pressure had held steady for a few minutes; then, somewhere about the time the torpedo must have reached the planet’s surface, or shortly thereafter, they had both started erratically downward — very erratically, indeed; there was even a brief rise above normal temperature. The recorder had been stopped when the temperature reached the freezing point of sulfur, probably by air solidifying around its moving parts. It had not resumed operation. The planet was apparently a heat trap, pure and simple.

There was no direct evidence that the suit had leaked gas either way, but Ken rather suspected it had. The bluish tint on portions of the metal might conceivably be the result of flame — flaming oxygen, ignited by jets of high-pressure sulfur coming from minute leaks in the armor. Both sulfur and oxygen support combustion, as Ken well knew, and they do combine with each other— he made a mental note to look up the heats of formation of any sulfides of oxygen that might exist.

He turned away from the debacle at last.

“We’ll let Feth look this over when we get back,” he said. “He may have better ideas about just how and why the insulation failed. We may as well go on to Planet Four and see if it has anything that might pass for soil.”

“We’ve been orbiting around it for some time, I imagine,” Drai responded. “Lee was supposed to head that way as soon as we got your suit on board, but he was not to land until I returned to the control room.” The two promptly glided forward, pulling their weightless bodies along by means of the grips set into the walls, and shot within seconds through the control room door — even Ken was getting used to non-standard gravity and even to none at all.

Drai’s assumption proved to be correct; drive power was off, and Mars hung beyond the ports. To Sarrian eyes it was even more dimly lighted than Earth, and like it obviously possessed of an atmosphere. Here, however, the atmospheric envelope was apparently less dense. They were too close to make out the so-called canals, which become river valleys when observation facilities are adequate, but even rivers were something new to the Sarrians. They were also too close to see the polar caps from their current latitude, but as the Karella drifted southward a broad expanse of white came into view. The cap was nowhere near the size it had been two months before, but again it was a completely strange phenomenon to the gazing aliens.

Or, more accurately, almost completely strange. Ken tightened a tentacle about one of Drai’s.

“There was a white patch like that on Planet Three! I remember it distinctly! There’s some resemblance between them, anyway.”

“There are two, as a matter of fact,” replied Drai. “Do you want to get your soil from there? We have no assurance that it is there that the tofacco grows on Planet Three.”

“I suppose not; but I’d like to know what the stuff is anyway. We can land at the edge of it, and get samples of everything we find. Lee?”

The pilot looked a little doubtful, but finally agreed to edge down carefully into atmosphere. He refused to commit himself to an actual landing until he had found how rapidly the air could pull heat from his hull. Neither Drai nor Ken objected to this stipulation, and presently the white, brown and greenish expanse below them began to assume the appearance of a landscape instead of a painted disc hanging in darkness.

The atmosphere turned out to be something of a delusion. With the ship hanging a hundred feet above the surface, the outside pressure gauges seemed very reluctant to move far from zero. Pressure was abut one fiftieth of Sarr normal. Ken pointed this out to the pilot, but Ordon Lee refused to permit his hull to touch ground until he had watched his outside pyrometers for fully fifteen minutes. Finally satisfied that heat was not being lost any faster than it could be replaced, he settled down on a patch of dark-colored sand, and listened for long seconds to the creak of his hull as it adapted itself to the changed load and localized heat loss. At last, apparently satisfied, he left his controls and turned to Ken.

“If you’re going out to look this place over, go ahead. I don’t think your armor will suffer any worse than our hull. If you have trouble anywhere, it will be with your feet — loss through the air is nothing to speak of. If your feet get cold, though, don’t waste time — get back inside!”

Ken cast a mischievous glance at Drai. “Too bad we didn’t bring two suits,” he said. “I’m sure you’d have liked to come with me.”

“Not in a hundred lifetimes!” Drai said emphatically. Ken laughed outright. Curiously enough, his own original horror of the fearful chill of these Solar planets seemed to have evaporated; he actually felt eager to make the test. With the help of Drai and Lee he climbed into the armor they had brought from Mercury, sealed it, and tested its various working parts. Then he entered the air lock of the Karella, and observed his instruments carefully while it was pumped out. Still nothing appeared to be wrong, and he closed the switch actuating the motor of the outer door.

For some reason, as the Martian landscape was unveiled before him, his mind was dwelling on the curious discoloration of the suit that had been exposed to Planet Three’s atmosphere, and wondering if anything of the sort was likely to happen here.

Curiously enough, one hundred sixty million miles away, a thirteen year old boy was trying to account for a fire which seemed to have burned over a small patch of brush, isolated by bare rock, on a hillside five miles west of his home.