by Hal Clement
"Well, why not in that range? Anyone can travel over six miles an hour on the moon—we found that out for ourselves."
"A person can, yes; but would he travel eighty miles practically nonstop, with no food, even on the moon? Tumble might have been in quite a hurry, but I doubt if it was that big. Besides, we've just found that he didn't stick to the course the mathematicians thought he would; he went farther to the right, if we're where we think we are. If he kept bending like this, he'd never hit that range at all—he'd wind up at the rim of this walled plain that holds the north pole. He'd know that that wasn't the place he was looking for; Tumble has watched this part of the moon too often and too closely to mistake even a forty-mile crater for the Mountains of Light, hard as it is to tell the difference from Earth. Remember, he got better looks at it than anyone on Earth ever did when he was using the telescope in the station.
"I think that somewhere along his route, probably not too much farther along it than we are right now, he found that he was heading the wrong way and managed to correct course."
"But how could he have known it here?"
"I don't know, but I haven't seen as much of the neighborhood as he must have. He's no mathematician, but maybe the motion of the sun gave him a clue; maybe he suddenly realized that there was no reason to expect the regular North Star to work here, and headed for the first mountain range he saw after that. He could see the Mountains of Light from here, too; at any rate, we can!"
"Hmph. Then what do we do? That spreads out the field of search an awful lot."
"What I'd like to do is travel on foot along the side of this ridge toward the mountains, to see whether Tumble left it at any point to go in that direction. If he didn't, then he must have kept along the ridge the way he started."
"We don't really know that the tracks down here were made by him coming toward the ridge," Dart pointed out. "He might have been going away, instead. Those grooves in the dust don't tell a thing about which way a person is going."
"That's true," admitted Peter, "but it seems a little queer that he should be heading away from the sun."
"Maybe he was trying to go back to his ship."
"He should have known it would be in darkness by now."
"We don't know when he passed this way; maybe it was before sunset at that point."
"Then why didn't he use his radio? We were at, and over, the site of the landing until awfully close to sunset time."
"I suppose that's so. I'd kind of like to check up on the Tumblesauce just now, though; we'd feel pretty silly if he was back there all the time."
"If you can think of a way to find it in the dark, go ahead. Just the same,. I'd like to make the walk I just mentioned; and I think one or both of you should fly along to the far end of this ridge, to check whether he left it there. If he didn't, maybe one of you could walk back along each side; then we'd cover the whole thing, and know where he left it—or if he's still on it."
"I think that's the best plan," Bowen cut in from his distant listening point. "Just one thing, first. Peter is several hours' walk from his ship. One of you should fly him back to it, so that he can bring it closer to the area where he is searching. Then go ahead as you've outlined."
This seemed a sensible point, and the boys wasted no time following it. Dart returned to the Jabberwock and took off along the ridge, while Bart, directed by Peter, went in search of the Jon. It was easily found— for one reason, the sun was so low that even Peter's set of footprints cast a shadow which could be seen from overhead as a straight, black line running across the face of the moon, as easy to follow as a railroad. Two or three minutes' flight brought them to rest beside the Ion, and Peter gladly went back to his own ship. He had no objection to the way Bart flew, but he was happier in a rocket which he himself was handling. He took off at once, returning along the line of footprints they had just followed, while Bart used his radio compass to home toward his brother's rocket.
Peter tried to plan out his time as he flew. If he landed where he had found Tumble's prints and started walking as he had planned, he could count on perhaps five miles an hour. He could get the distance to the other end of the ridge from the other boys, who must be there already—at least, Dart must be, unless it was remarkably long. The map did not show it; it had been lined up so nearly with the direction of the sun when the original map photos were taken that its shadow did not appear on them.
There might, of course, be delays; in several directions he could see long lines of black on the surface which might be fairly deep cracks, though he had been lucky so far in his walking and had never come across a crevasse deep or wide enough to stop him. Perhaps he had better drift along over the route of his planned walk first, though; if there were any very wide ones, he could plan to leave the rocket near enough to them—but no; none of them was likely to run far enough to prevent his getting around them by a short climb. The few he had met in his first walk along the ridge had always stopped before the ground rose very far. He decided to let things come without too much planning, and settled toward the place where the trail of the missing boy met the end of the rise.
There were cracks, at that; one of them was in a rather annoying position, leading away from a point near the end of the high ground, perhaps half a mile from where Tumble's tracks showed and angling off toward the' distant Mountains of Light. That meant that if Peter were to cover all the possible places where Tumble could have left the ridge there would be a delay almost at the beginning, for he would have to start at the trail and go only half a mile before having to climb around the head of the crevasse. He was tempted to skip that half mile; after all, what were the chances that Tumble would have left the ridge so soon? Besides, he should be able to see any trail going toward the Mountains of Light; it would be heading across the sunlight, and should cast as sharp a shadow as his own........
Peter almost let the rocket drop the remaining two hundred yards to the ridge as he suddenly realized where his thoughts were leading. He did make the hardest surface landing the Jon had experienced so far; it was lucky that the boys had been leaving their landing "legs" extended during all their short flights near the moon, for he would almost certainly have forgotten to put them out, and in consequence been marooned just as Tumble had been.
He broke all records for getting out of the ship, though even in his excitement he did not forget to check the airtightness of his suit. He did not examine the half mile of ground between the trail and the crevasse; he headed straight for the latter as fast as he could travel. That, going downhill and in a gravity where he weighed less than forty pounds complete with space suit, was quite fast.
As he approached, the fine black line grew more distinct but less regular. Even before the real details were visible, he knew what he was going to find; but he didn't dare make a report until he was at the foot of the ridge, where the dust started again. There he saw clearly before him, stretching toward the horizon and the Mountains of Light, the line of shallow grooves in the dust which were Tumble's footprints. The mountains themselves were not visible from this level; the redhead must have seen the peaks from the top of the ridge, and somehow guessed what they were. At any rate, he had certainly gone toward them.
Peter was leaping back up the ridge toward the Ion as he called the other boys. There was no answer from them; they must have landed, and the radio waves were cut off by the horizon. It did not matter; the people in the station must be hearing him, and he could get in touch with the boys as soon as he had taken off.
He went inside as rapidly as the tiny air lock would let him, and fed power to his main drive almost before the inner door had closed behind him. Three seconds later he was following the thin line of black toward the mountains, giving most of his attention to keeping it in sight while he made a detailed report into his ship radio. Bowen acknowledged at once, Bart and Dart a few moments later. They had just been getting out of their ships, and had not heard him at first. They hastily got back in, and took off toward the mo
untains.
Peter followed the trail as far as he could and as well as he could. Twice there were breaks; apparently low ridges, bare of dust, had crossed the boy's path, but he had not followed them. The trail went on in a straight line after each interruption, toward the mountains.
But not to them. Tumble had been heading that way, that was certain. Maybe he had made it; but at the lowest slopes of the mountains the sun had practically set, only a tiny rim of its bright disc remaining above the horizon. Every tiny irregularity in the ground cast a shadow far longer than itself, breaking the landscape up into a pattern of dead-black streaks interrupted by narrow areas that looked bright by contrast in spite of the low sun and the actually dark color of the rock. The higher parts of the range looked blinding for the same reason, where they thrust upward into full sunlight.
For scores of miles that line of bright saw-teeth extended, points of light jutting from almost invisible bases. If Tumble were here, he must be well up one of the mountains by now—or trying to get up. He would know that only on the peaks would he get the steady sunlight his air purifier needed. But which peak would he have tried for? If he still did not answer to radio, how could they all be searched? Bart's voice came through the receiver, summing up the situation.
"I guess we get our first mountain-climbing practice in the dark!"
22
NO EXIT
"ALL of you! Hold your ships where they are, as nearly as you can manage!" Bowen's voice snapped from all three radios. The boys wasted no time in questions; Uncle Jim seldom used that tone. Each of them brought his rocket into a tail-down attitude and adjusted his power to offset the moon's gravity; then they checked drift, and tipped far enough to reduce any speed they might still have to zero. Peter, who was going fastest when the order came, was the last to report that he was stopped.
"All right," came the answer. "Now, I suppose Bart and Dart started from one place and Peter from another, and all headed for those mountains; is that right?" The boys admitted that it was. "I thought so. You were a good many miles apart, and couldn't see each other. You still can't, I suppose." Again he was right. "Then do some thinking—all of you. I know you're used to the idea of shooting around at fifty miles a second or more, at least on long trips; but please remember that if one of those machines hits another at a relative speed of even fifty miles an hour, there'll be nothing but a ball of tinfoil somewhere on the moon. Now get together where you can see each other's ships before you do anything more about searching. Peter, you should be closest to where you all want to go; turn up your transmission so that they can home on you. Dart, you go first while Bart stays put; then report when you see Peter's ship, so Bart can start."
"Yes, Uncle Jim." The boys were a trifle sobered by Bowen's words; Peter spent some time figuring out how long there would be for the pilots to dodge if two rockets approached each other at a mile a second, were not noticeable to each other at more than half a mile, and the pilots each had a reaction time of a tenth of a second. The answer made him uncomfortable.
Several minutes passed before the three rockets hung side by side perhaps five miles above the moon's surface; then the question arose of just what should be done next. Tumble's trail had been hopelessly lost, as far as being spotted from above was concerned, in the pattern of shadows at the foot of the range. It might be followed by a person on foot, even in the darkness where the sun did not reach; but there was the nea/ certainty that the moment the boy had started to climb he would have been on bare rock, and leave no trail anyway. There was no point in trying to bring a rocket low enough to check that point; aside from the danger of flying among the peaks, the jet stream would, as Peter had said, blow away the dust which held the footprints.
"It looks," Peter remarked, "as though you were right, Bart. We do some mountain climbing. I suppose we'll cover the place fastest if we take a mountain apiece............"
"I hope I didn't hear that correctly," came Bowen's voice. "I don't much like your climbing mountains in space suits as it is, but you're there and I'm not; if you think it's the only way, I suppose it is. However, one of you stays in his ship so that messages can get from me to you—I know I can hear you all right, but that's not enough. Also, you will climb only when the station is above the local horizon; the rest of the time, you come back here to eat and rest. I know that will cut over fifty percent off your search time, but that's the way it will be. Now, who stays with his ship?"
All three names sounded at once, though they were not spoken by their respective owners.
"All right, you all want someone else to stay. I'll settle it to save time. Peter goes, because he knows Tumble best and is most likely to get ideas about what he'd do on a given spot. Bart goes, because he had to stay with his ship last time. Dart, it would be best if you took your ship up ten or fifteen miles, so that you'll be above them and there won't be so much chance of a spur of rock cutting off radio contact."
"But Uncle Jim........"
"Save it! You agreed that I was the commander, and you were my eyes. You're sharp youngsters, but you still let things interfere with your judgement. As long as that happens, we'll use mine. You're wasting time, Dart."
"Yes, Uncle Jim." Dart added power enough to send his rocket drifting upward without further argument, while the others let down toward a more or less level spot fairly close to the foot of the range. It was not level enough, as it turned out, except in very small areas; Peter had to hold a few feet off the ground while he directed Bart in to a landing. With his power off, Bart then returned the favor. It would have helped a great deal if the pilot were able to see directly below his ship while it was in landing position.
Both boys got out and looked around. Only a tiny sliver of the sun was visible; most of the ground could be seen only in the relatively faint light reflected from the peaks. Walking would be treacherous; it would not be easy to tell whether a dark patch was a shadow across a two-inch-deep hollow or a fifty-foot blowhole. The ground was definitely volcanic, or what would have been called volcanic on Earth; irregular masses of rock not only contributed to the shadows but suggested unpleasant things about what might lie in a shadow. A spur of sharp lava, unseen until one walked into it, might puncture a space suit. Flashlights were a necessity, and travel would be slow.
"Might as well start," remarked Bart after a few moments' examination of the surroundings. "Any preference on mountains?"
"Yes. I'll take this on my side because it's the tallest in this part of the range, and it and the one beside it are closest to the line Tumble was taking when we last saw his trail. I think he'd take the high one to be surer of sunlight, but we'd better cover them both to play safe. You take the other one. We have a few hours before the station sets; we'll cover what we can of these hills. Keep using your radio; if Tumble's silent just because he's cut off, you never know when we'll be in position for him to hear us."
"Right." They started without further discussion.
The climb was even harder than they had expected. There was no possibility of standing on a high point and looking over a large area at once; any black spot one could see might be deep enough to hide a space-suited boy, particularly one Tumble's size. Every square yard must be covered. Peter did not let himself figure out the number of square yards; he didn't want to get discouraged any earlier than he could help.
Sometimes there were patches of dust, caught on level places or in hollows on the slopes; but there was never a trace of Tumble's passage in any of them.
The only thing which made the task possible at all was the lack of erosion on the moon. The mountain was still much as it had been when it was first formed; only spalling by the fierce solar heat had softened its outlines a' trifle. There were no gullies, such as a stream would cut in a mountain on Earth; no potholes such as a glacier might leave; no dunes such as wind might pile.
There were occasional crevasses, and deep holes which looked as though they had been blown by gases escaping from still plastic lava; Peter se
nt his light beam probing into each of these that he found, but all were empty save for the dust, which seemed to be everywhere on the moon where it could settle. He felt a little uncomfortable when he reflected that the light of his flash was probably the first thing to disturb these holes, or some of them at least, for millions of years. Even some of the dust clung to their walls instead of working its way to the lowest level, as it had done out on the surface.
The sunward half of the mountain had been covered better than Peter had expected by the time Dart relayed the call to return to the station, but there was still a lot to be done. The searchers obeyed the order; back at the hunt some twenty hours later, they admitted to themselves that they were better for the food and rest, even though the wait had been long.
Dart had suggested putting the station into an orbit which would not take so long to get it back into sight of the Mountains of Light, but before Bowen's marrow had had time to chill at the thought of more maneuvering, Peter had pointed out that any such orbit would mean staying in sight of them for a much shorter time, as well. Right now the station, more by accident than design, was in a path which did keep it in sight of the north polar regions more than half the time, which was a pretty good compromise—to do that, its path had to take it a scant two hundred miles above the south pole of the moon, while it rose some eighteen hundred above the north.
But even twenty-odd hours above the horizon was not enough, in one way. The boys, naturally, could not search that whole time; they had to return to their ships to rest and eat, resenting every minute so spent. Tumble had been away from his ship for something like four days; the longer it took to find him, the less were the chances of finding him alive. None of the boys had ever been really hungry, but they were able to guess vaguely how Tumble must be feeling by this time.
As the search period wore on, and the sun drifted farther and farther around the horizon without getting lower, Peter in particular began to feel the hopelessness of the situation. He had never been a quitter, but at the rate they were covering the range he could see all too clearly the length of time it would take to finish the job; by no stretch of his imagination could he see how Tumble could live that long. It seemed likely that the boy would have climbed the first really high peak he found after reaching the range; but had he?
