Complete Short Fiction, page 250
Nothing offered the slightest clue, to his eyes, as to the whereabouts of the radiation source. Nothing suggested, even remotely, anything artificial. No works of intelligence could be expected to have survived a billion years even of ordinary planetary environment, of course, far less what must have happened while Anu was turning up his output nearly three hundred times. It would be fun to try to work out in detail what had gone on as atmosphere and oceans were stripped away, tectonic forces readjusted to the changed restraints on the crust, and rising temperature altered the rocks themselves; but that would have to be faced later. Any normal person could get years of recreation out of Tammuz. Some of the Ishtar colonists already had, and Cunningham expected to; but the planet would wait. This radiation problem might not.
A radar scan showed no sign of metal, but did bring response in the form of a similarly patterned beam of much lower power. The imitator was still at work. Cunningham located the source as precisely as he could in terms of the visual images. From his present distance, the uncertainty was ten kilometers or so. A survey specialist ship would have been able to locate it within a meter; retirement-hobby craft didn’t carry such equipment unless the hobbyist made it, and Cunningham’s interest lay more in the direction of personal communication with nonhuman intelligences.
What he did manage was a set of good photographic images, the equivalent of a map for practical purposes, for ten kilometers or so around the most probable location of the emission. He could have done better from a lower altitude, and if he had been sure that this was a matter of communication he would have; but he was still inclined to suspect that some natural, and hence basically unsympathetic, phenomenon was behind the whole affair. He remained cautious.
There is, of course, a perfectly good technique for determining whether a response to a question is a simple echo or not. Cunningham knew it perfectly well—he had even used it more than once—and was extremely annoyed with himself afterward for not thinking of it at the very beginning. He had, he decided, attached too much weight to the reaction time.
He was just finishing the picture mosaic when it occurred to him, and with an exclamation of irritation he snapped off the viewing projector and took the few steps which brought him back to the controls—nothing inside Nimepotea was more than a few steps from anything else; the ship was no place for a claustrophobe, especially after Cunningham had been exploring and collecting for a few years without visiting home.
He turned the radar beam back on, aiming it at the area which had now become quite familiar to him from the photographic work, and waited briefly for the response.
And waited longer for the response.
And longer still.
There was no echo, other than normal radar ones. For a moment the man was even more annoyed; then he brightened. Maybe this was intelligence, and they were tossing him the ball—expecting something new. He was rational, more or less, but human.
He turned the beam off. Then he turned it on once, briefly, and once again. He waited a few seconds, then turned it on twice, paused briefly, and four times. Another wait, three flashes, then nine.
Then he waited.
Nothing happened. X was asleep, or out to lunch, or had lost interest in playing with strange signals, or couldn’t see in this direction.
The last idea could conceivably be checked. Cunningham reached for the photomosaic, then firmed his lips and turned back to the control console. Risks or no risks—and he didn’t really believe there were any—the time had come for a close, personal look at that area. Nimepotea plunged downward, and within minutes was hanging a kilometer above the center of what seemed to be the important section of Tammuz’ landscape while its pilot’s fingers played over direction and field controls of the view screen and his eyes rapidly scanned the screen itself. Almost by reflex he oriented his image with respect to the planet’s rotation axis; being able to apply terms like “north” and “east” helped the memory a lot.
The eastern edge of the imaginary square which seemed so important was cut by the rim of a ten-kilometer impact crater which had clearly formed later than most of the rest of the landscape. Its nearly perfect circle was unaffected by hills, plateaus, and an ancient graben which postdated the first two. The plateaus were the most significant features; except for one detail they resembled the mesas of the North American southwest, and covered fully half the local landscape.
The exception was their edges, which were angle-of-repose slopes rather than steep cliffs. The rock was light-colored, as close to white as anything Cunningham had seen on Tammuz even from a distance which permitted a view of most of a hemisphere. It might conceivably be limestone, and the area represent the erosion remnant of a region of horizontal sediment—except, of course, for graben and crater.
The question was whether any caves or overhangs, which could easily have formed in such country during the early stages of weathering as they had on Earth, would still be present when the destruction had reached a general stage of sand slope. This was especially true since the weathering had presumably occurred while Tammuz still had an atmosphere, while the nearby impact feature might not have—and its arrival would probably have shaken down anything with room underneath for a hundred kilometers around. He could look for holes, or he could fly a search grid over the area while broadcasting signals and listening for possible response from X.
He was going, of course, to have to get out and do some foot exploring sooner or later, and one part of his feeling suggested that it might as well be sooner; but native caution had not faded out completely. If nothing else, he should certainly not step outside until he had a good map of the general area firmly in his head.
He could memorize the map while flying the search, so he started the latter. He dropped the ship to five hundred meters above the general plateau tops, which in turn was about seven hundred above the level ground separating the mesas and perhaps a thousand above the bottom of the crater. Starting at the northwest corner of the key area, he headed east at a low speed, about fifty meters a second; he wanted to give himself time for a good look at everything. At the eastern edge of the area, north of the crater, he turned south for two hundred meters and then made the westward cast of his grid. Patiently, back and forth, keenly watching for any detail which might suggest the presence of X, with the ship automatically broadcasting the sequence he had set up earlier and which any intelligent being should reasonably answer with “four-sixteen.” Presumably.
The three-hour flight produced no response to the signals, but left Cunningham ready to spend time out on the planet’s surface if he could only find something worth checking closely. Nothing seemed to offer the slightest danger to a reasonably equipped explorer. Landslides could no longer occur, since all slopes seemed to have reached angle of repose in the mesa area. It was furiously hot, naturally, but his armor could handle that. There was no air, unless a few hundred molecules of carbon dioxide per liter deserved the name, but again that was what space armor was for.
After sleeping, he would go outside and get mineral samples; the makeup of the local rocks should be checked, if only to confirm the guess about their silicate nature—or, in this area, limestone, he reminded himself. Maybe there would be fragments large enough to show fossils, though none of the Ishtar colonists who had visited Tammuz had found any so far.
After a moment’s thought, he grounded the little ship in a valley between two of the mesas, where there would be some shade when Anu sank lower in the sky; there was no point in making Neem’s refrigerators work harder than they had to. Gravity was not merely adequate but really comfortable, and after setting his controls to arouse him if X did any broadcasting, he was able to sleep long and deeply.
When he woke up, Anu had set. The brightest object in the sky was the red dwarf of the system, Ea, which was at a distance which made it totally inadequate as a sun though uncomfortably bright as a star. Cunningham considered going out to get his samples by artificial light, but decided against it. He could spend plenty of time thinking; there was certainly enough he did not at the moment understand. He should spend more time thinking. He suddenly realized that he was almost taking for granted that X was intelligent. While this was certainly possible, it was also a little too close to the demon hypothesis for comfort; normally educated human beings usually had a strong tendency to hunt for natural explanations for anything they didn’t understand. It was probably backlash from the heavily mystical stage the species had gone through a few centuries before, Cunningham suspected; but he had the conditioning, and felt the need to come up with some explanation for what had been happening which did not include conscious intent of persons unknown.
Hours of thought, punctuated by minutes of eating and other hours of sleep, failed to produce any before Anu rose and provided daylight.
Even with no atmosphere, scattering of light from the upper valley walls made the ground quite bright enough for comfort as soon as the sun was up. Ea could still be seen, though it was not far from setting; no other celestial objects, stars or planets, showed against the glare of the sunlit rock.
Cunningham donned and checked his armor with the care that befitted his age—or at least, befitted the fact that he had reached his present age. Without bothering to move the ship from the middle of the valley, he emerged from the air lock and walked toward the mesa slope half a kilometer away.
The rock under his feet was plainly sedimentary, fine-grained stuff; shale, presumably. It could have contained fossils, though the surface was hardly a likely place for them to show—one topographic feature conspicuously lacking was stream cuts. If anything, the rock seemed to have been polished by dust or sand. Since this would have had to be blown by wind, it could hardly have taken place recently; there should be meteoritic gardening in the ages since the air had gone. The man kept alert for signs of this, but saw none before reaching the foot of the valley slope. He had walked across nothing but incredibly smooth rock, with no evidence that anything had happened to it since Tammuz’ atmosphere had vanished.
He could not, of course, expect to see any microscopic craters which might have been left by dust-grain impacts, and a few meters from the foot of the wall he cut a section out of the rock with his sampling beam, to take back to the ship for more detailed examination.
The sloping side of the valley was not merely sand or soil; it was finest dust. As he had judged, it was at its angle of repose and was utterly, impossible to climb; Cunningham made a cautious attempt, but the powdery, utterly dry stuff slid under him without offering the slightest support. He did not try too hard. The material was ferociously hot as well as fine and dry; if he were to get buried in it so that his heat pump could not radiate, he could expect to cook in less than a minute. Just being on a planet, with half the potential radiant heat sink of the universe blocked, instead of in relatively empty space made things difficult enough for the equipment. If he did find a cave or overhang, he would have to be extremely careful exploring, or even approaching, it by daylight.
There seemed to be nothing to do but collect some of the dust for analysis, and either return to Nimepotea or bring the ship to him. He hesitated briefly at the latter thought. Then he remembered that X had already displayed its ability to send out control signals to the ship without merely copying his own, and that he had unthinkingly turned on the remote control receivers when he picked up the spindle before leaving the vessel. Neem had been vulnerable to abduction for the last fifteen minutes, whether he used his own control or not. He muttered several self-derogatory remarks in German and Finnish—he had spent several years on Neu Schwarzwald before his time on Omituinen. He was not particularly bothered about the existence of the risk, but very annoyed at himself for not recognizing it sooner.
He wondered later whether the irritation was what caused him to elevate the ship higher than was strictly necessary merely to bring it the few hundred meters across the flat valley floor to a point beside him. Neither cameras nor any other kind of recorder was running; improving the chance of intercepting any of X’s output would do Cunningham no good, since he wouldn’t be there to see or hear it. Nevertheless, he sent Nimepotea almost up to plateau level before starting it toward his position.
He comforted himself later with the recollection that he did keep a close eye on the little craft as she moved, so he was able to say with some certainty that the foreign signal did not reach it until it was over a hundred meters above the ground. Then it must have been overpowering; Neem made not the slightest motion toward Cunningham’s position, but headed northeast along the valley on a long slant which he could see would bring it into collision with one of the slopes if the course were not changed.
He aimed the spindle and ordered the ship to come in his direction, using the highest power the controller could send. He thought he saw a slight hesitation in its motion, but wasn’t sure; it kept on toward the valley slope kilometers away. He shifted to a homing command and held the guide beam aimed as steadily as he could. Homing was supposed to override specific maneuver programming, but this one had no effect. It was as though Nimepotea were already homing on a stronger beam, which Cunningham decided was likely enough.
If that were true, he was being given some indication of the location of X, at least; Neem must be flying straight toward it. On the plateau? Under it? Beyond it? Would X try to fly the ship through the ground?
Not very far, certainly, since the control waves would penetrate only a short distance—just how far would depend on the nature of the material, but two meters seemed a generous maximum, especially if Neem were receiving a guide beam strong enough to override Cunningham’s own.
Keeping his eyes almost continuously on the ship, the man began to trudge along the hot rock after it. Would it disappear over the top of the mesa, or was it a little below that height? He could not be sure. It would be two or three minutes at its present speed before the matter was settled, and by then it would be pretty far away—not too far to see if it plowed into the dust, but too far to see how much damage resulted. In theory there should be none, of course; automatic controls would override the remotes if the hull met really firm resistance, but Cunningham would have been much happier to be at the console himself to take care of such matters.
He stopped when the ship did the same. It was below the hilltop—not very far below, perhaps eight or ten meters for the long axis of its ovoid hull. Unhesitatingly, though without much hope, he again beamed a homing signal at it. It moved at the same instant, as nearly as he could tell, but not toward him. First it shifted out from the slope for perhaps twenty meters; then it moved straight down until it touched the ground again, perhaps sinking in a short distance—this seemed likely under the circumstances, but the man could not tell at this range. Then it moved out again, and down again, repeating the process to outline a set of steps all the way down the slope until it was within a few meters of the level rock of the valley floor.
Cunningham could see that the hull must have penetrated the loose stuff at least a short distance, since the ground itself was moving downhill—not very much, just enough to fill the fresh dents made by Nimepotea, since the powdery stuff had already been at its angle of repose at least since the nearby crater had formed and probably for millions of years or so before that. He barely noted the motion; he was running as fast as he thought he could keep up in a space suit toward the point where his ship hung, possibly within reach. He did not send any more control signals; if Neem were going to stay put, he was glad to settle for that. The spindle was in his hand as he ran, however.
Twenty-five minutes of slogging over rock hot enough to melt lead could have been painful, but his suit refrigerators held up. He was not really worried about them; almost his entire attention was on the hull which he was approaching with such painful slowness, not sure when or whether Neem on its own, or X, would decide to put it somewhere else. In spite of his relative success in predicting some of the things X had done, he felt no real confidence in his analysis of that character—or even any real certainty that it was a character. If it were, its motivation had to be curiosity—it was trying to find out things about the control impulses. What it could observe of the results of its experiments could only be guessed, so far; perhaps the recent maneuver implied that it couldn’t see the ship and sensed, or detected somehow, only the microwave output Nimepotea used for the control feedback. If the homing system had been in use just now, that would account for its allowing the ship to fly into the valley wall; now it might be trying to figure out why Neem had ceased to obey orders.
Maybe.
And maybe it would start another test at any moment. Cunningham, sweat soaking his clothing far beyond the environment armor’s ability to handle, drove himself even harder at the thought. There was plenty of light—Anu’s monstrous disc was almost entirely in sight now above the eastern valley wall—but there was no way to wipe sweat out of his eyes, and seeing was getting difficult.
Half a kilometer to go. Three hundred meters. One hundred. Twenty. On the little satellite, he could have made the remaining distance in a single leap, but on Tammuz his weight was fairly normal.
Now he was standing under the ship, the open air lock ten meters out of reach, the lowest climbing rung five. It was not straight above him, but a little way over the slope of glaring white dust which formed the valley wall. His mind knew what would happen, but his feelings made him try anyway; he started up the slope, slowly and cautiously.
