The Logical Life "Excuse me, Laird." T'Nekku put the helm hard over, and his boat swung about so that her bow was into the wind, the boom trailing aft just above the giant's head. The human passenger swung the infrared flash in his hand to see what his friend, pilot and guide was up to. The Tuinainen was partly hidden by the mast and rigging—Cunningham was riding as far up in the bow as he could get, in the interest of comfort and safety for both of them—but the beam showed fairly clearly the bulky pyramid that was his body. It looked whitish, but color of course was meaningless through the converter goggles. The native had stood up without disturbing the boat's trim—it was merely a matter of straightening the four blocky legs which supported him—and seized a harpoon. Judging by the weapon's position, his attention was directed off to port; Cunningham swung the flash in that direction, but could see only ocean. He pushed up his goggles for a moment, but unaided human eyes did no better. The Orion Nebula covered a quarter of the sky behind him, and several O-type stars lay within a parsec of Omituinen; but starlight is still only starlight and no nebula is much help to Earthly optics. "What's the trouble, Nek?" he asked. "Anything I can do?" "Nothing," came the rumbling voice of the native. "It's a kind of fish you haven't seen, or at least we don't have a common word for it. He's hungry too, I judge; just a moment while I settle who eats whom." The harpoon suddenly vanished; the arm holding it had swung too fast for Cunningham's eye to follow. The missile plunged into a wave with a barely audible schloop twenty yards away, and the ocean surface erupted into a cloud of spray. The man was not sure whether to be frightened or not. T'Nekku seemed to be taking the whole matter calmly, but the only emotion Cunningham had ever seen him show was humor. The giant took the serious things of life with a calmness few human beings could even emulate, much less feel. The man wondered whether the fish represented a real menace or not. He could tell from the splashing that it must be quite large, but the boat was over thirty feet long and, in spite of its bone frame and skin covering, solidly built. The 'Tuinainen was playing the harpoon line, hauling in when he could, letting out when he had to. Evidently the fish was trying to escape rather than attack, which was some relief. Judging by the sound, it was leaping out of the water repeatedly. Cunningham wished he could see it. Several times the boat heeled several degrees toward the scene of the struggle, but presently the splashing became less violent, the hull righted itself and T'Nekku began to haul in steadily, coiling the line beside him as he had not had time to do before. At last his quarry was alongside. With the aid of a noose that he slung outboard and maneuvered briefly, the native hauled into view something which might have come straight from a Gulf Stream marlin contest. Cunningham was not too surprised. Omituinen had some weird-looking land life, his guide being far from the least remarkable; but there is such a thing as parallel evolution, and a fish does have the engineering requirements of a fish. T'Nekku did something, Cunningham could not see just what, and the creature stopped struggling. The rumbling voice came again. "Do you want to examine this before I eat it?" The words were in well-enunciated Lingua Terra. The man hesitated a moment before answering. "Not unless the ocean is a lot warmer here than around your islands," he finally said. "Have you felt it, or should I check by instrument?" "It is a little warmer than at home, but still comfortable. With your strong feeling for numbers, you should probably use your thermometer. I can wait a few minutes even though the fish is here, but please waste no time." Cunningham knew better than to waste time. Like men, the 'Tuinainen had two kinds of appetite—the habit-and-memory-controlled intellectual one and the more emotional one triggered by the actual presence of food. However, they had less control than an adult human being over the latter, and Cunningham was acutely aware that T'Nekku outweighed him five to one and was correspondingly strong. His instruments were small and light, since he was planning to carry the kit for long distances on foot under Omituinen's fifty-percent-over gravity. He whipped out a thermometer, made sure his airsuit glove was tight at the wrist, and reached overside into the ammonia ocean. Waiting a second or two for the instrument to equilibrate, he pressed the lock button and brought it up to his flash to read. "Six degrees up. Maybe you'd better let me have a small slice. Be sure it includes some skin, please." The 'Tuinainen made some more obscure motions and boomed, "Ready to catch? Or should I toss it on the deck beside you?" "On the deck, please. I can't see well enough to trust myself for a catch, even if I were sure of my reflexes in your gravity. Good eating." There was a thud beside him, and he picked up the sliver of tissue and slipped it into the freezer installed in the bow. Detailed examination would have to come later, under much more suitable conditions. T'Nekku in the meantime was using a couple of hands to devour his catch and the others to bring his vessel once more onto course. The first operation took longer, but even that was completed in a very few minutes. He left nothing of the fish, though the man knew it had bones—he heard them crunch as the native ate. The wind, dead astern, was the only way Cunningham could tell they were on course, though keeping the nebula to his left also meant something. The island the man wanted to visit was a heat source according to the long-wave maps from space—that was why he wanted to go there. Omituinen was a sunless planet. It had condensed from cosmic dust, just as the solar system had, but lacked the mass or the hydrogen content to be a star. Its parent cloud, in the Orion area, had been rich—by astronomical standards—in heavy elements; there was enough K-40 and uranium-series matter to have warmed the planet hundreds of degrees over the billions of years it had existed. It seemed that the radioactives had concentrated, presumably through zone-melting phenomena, so that some restricted areas of the world were actually volcanic. Indeed, Omituinen must have been much hotter at some time in the past, though radioactivity might not have been responsible—somehow it had gotten rid of most of its hydrogen, which was hardly more common than on Earth. To a human explorer, the main problem was the planet's lack of light. Cunningham would have been much happier if a spotlight or even a hand flash had not been a death ray to Omituinan life. He trusted his native friend, but still wished he could see where he was going. It was a frightening ride. Of course, clouds could be seen, silhouetted against the nebula or glimmering faintly in the starlight. Perhaps, like Columbus or Maui, he could use a thunderhead to find his goal, but the chances were poor. Sauvala, at the trading post on Uhittelava, had claimed he was crazy, the trader being well below retirement age and quite satisfied with ordinary dangers. The explorer had made no effort to explain to him what a few decades without meaningful work would do to a normal human mind—that a man has to do something. Competitive sports seem futile after a while, win or lose. The gratifying of physical appetites palls even sooner and is never a full-time satisfaction anyway. Aside from artistic expression, which is not open to all minds, only active research—any bit of which may suddenly turn out to be of life-and-death importance to mankind or even to all intelligence—can provide both the satisfaction of accomplishment and the necessary feeling of usefulness. So, at least, Cunningham felt. Sauvala was far too young to think so. He had helped, though. He had found the Terran-speaking T'Nekku, had supplied the maps Cunningham needed and had argued the pros and cons of the explorer's driving theory. The trader was a fairly good biologist himself, since Omituinen's principal export was enzymes, produced by its hydrazine-and-nitrate-using animal life. All the youngster had asked in return for his help was specimens to check for commercial value. This fitted nicely with Cunningham's own goal, which was to find something analogous to plant life, not yet known on Omituinen. The animals got their nitrates, hydrazine and, of course, ammonia from the sea; logically, since the planet was at least half as old as Earth, something must be replacing these compounds just as something was constantly replacing Earth's oxygen. Presumably, something anabolic was fixing the planet's atmospheric nitrogen, but no one had found the organism yet. So Laird Cunningham, driven by curiosity and by the human urge to accomplish something—and supported by confidence in a perfectly logical theory of his own—was sailing blindly across an almost unmapped ocean in a thirty-foot sailboat piloted by a being he had known for less than two Earthly months. T'Nekku understood the situation completely and had spent much of the trip discussing the matter with his passenger. Now, once more running steadily before the wind, he resumed the talk. "Laird, if your idea is right, we should be finding more and more fish as we approach the island and the sea becomes richer in food chemicals. So far I have seen no real change." "Are you sure? What I really expect is a larger quantity of the very small animals, to which you don't usually pay much attention. Actually I don't expect a really great change until we come fairly close to land—perhaps close enough to see the cloud which I expect will be above it." "I suppose the little net you cast from time to time is to check for these small creatures. I am surprised, with your strong feeling for numbers, that you don't measure in some way how much sea the net has traversed each time you use it." "I do time each cast." "But we are not always sailing at the same speed." "Surely it doesn't change very much. I hadn't been worrying about that at all. Can you tell how fast we are going at any given time?" "Not in numbers. I know whether we are going fast or slow." "Hmph. I should have brought some sort of log." The 'Tuinainen asked for an explanation and agreed with the man when he had received it. "I have nothing of the sort, I fear. I know where we are, well enough to find my way home, but I could not tell you in numbers anything about it. I judge that this would not help you with this net measurement." "I guess not," sighed Cunningham through his breathing mask. "I'll just have to do my best. Anyway, if we do start netting a lot of plankton it will suggest that I'm not too far wrong." "That seems sensible," agreed T'Nekku. "Your idea is that these things you call plants make the chemicals that fishes, and therefore people, need for food; that they live in hot places, so the nearer we get to a hot place, the more of these chemicals there should be in the sea. It seems logical enough. I know the world is big, but these things would have been used up long ago if there were not some way of making more." "Precisely. And making them takes energy, as I explained to you long ago." "If all this is of such great interest to you and your people, why has not one of them tried to find out about it sooner? The traders have been here for over ten days, and it did not take them even one to learn that there were things here they wanted." Cunningham smiled, not really cynically. "I doubt that I could tell you enough about star-traveling people to make clear the difference between those who have useful jobs and those who don't, since your people are still in the state where you do useful work or starve. Actually, the principal answer to your question is that there are many, many more unsolved problems in the Universe than there are beings interested in solving them—I am thankful to be able to say. It might easily have been a hundred or more of your days before anyone happened to hear about this particular one and get interested in it. It might not have been one of my species, for that matter." The debate went on until Cunningham had to sleep. The native was familiar with this human peculiarity and fell silent, while he guided the boat on under the glow of the nebula. He was quite willing to think silently, without disturbing his passenger. It was T'Nekku's voice, however, that wakened the man. "Laird! Look ahead! You said there might be a cloud shaped like that over your island, but you did not warn me of the light!" The human being stretched, straightened up and looked over the bow. It took only a moment for him to grasp what he saw. "Sorry, Nek. My fault. I should have foreseen it, though I must say this is a livelier thunderhead than I ever ran into on my own world or on any other." Actually, the view was still impressive only to someone who could fill in from reason or experience the portion still below the horizon—or to someone as vulnerable to high-energy quanta as the 'Tuinainen. The top of what was obviously a very large cumulonimbus cloud could be seen, partly silhouetted against wisps of nebula, partly showing dimly in the starlight and mostly illuminated by a continuous flicker of its own lightning.:. Continuous. For minutes they watched, and there was never a split second when the cloud went dark. It was obvious enough. The hot spot—presumably an island—was heated steadily by the radioactives that made Omituinen habitable, concentrated as usual by zone-melting phenomena. The convection currant had violent up (and no doubt down) drafts, intense rain, maybe hail—Cunningham wasn't sure about ammonia hail, but it seemed likely—and finally, predictably even though he hadn't predicted it, lightning. But that created a problem. So far, the cloud was little brighter than the nebula and was causing T'Nekku no real inconvenience; but how much closer could they get? Cunningham had expected the limit to be set by the native's heat tolerance, which was surprisingly high considering the ammonia in his body. How much closer could they get? Maybe he should have used his ship—no, the arguments against that were still sound. Divided attention, since completely automatic operation on a world so little known would be suicidal, was the worst but not the only one. However, if T'Nekku could get no closer than this, the whole expedition would have to be reconsidered. But that was not ascertained yet. Surely he could take more light than this. But that was up to him, especially since it was his boat. "Nek, I feel silly for not foreseeing this. I've seen lots of thunderheads before, and should have. I'll start taking water samples for later analysis—excuse me, I mean ammonia samples—and can only ask that you bring us as close to that place as you can. It's up to you when we back off." "All right, Laird. I can get much closer than this, though. If we approach with the cloud over the port bow instead of straight in, the sail will shield me from the light." "But what will happen when we start to tack out again?" There was silence for a moment—just long enough to let Cunningham wonder whether the native had actually forgotten that point or was merely testing his passenger. Then, the rumbling voice came back: "I could shelter myself with the spare sail—make a tent or just drape it over me." "Are you willing to take the chance?" "Sure. I am as interested as you are in finding out where our food comes from in the beginning." "All right, I won't fight it. You work us on in as best you can, doing everything you can think of to protect yourself, and I'll get to it with bucket and thermometer. Thanks." Conversation ceased, but not activity. The boat shifted heading a point to starboard and held it there. The man in the bow reached overside with instruments, tossed things into the sea with lines attached, examined items with his infrared flash, made copious notes and froze occasional specimens. The cloud rose higher ahead of them as the minutes passed, and the flicker of lightning grew ever brighter. The sea grew noticeably warmer, though it was still well below boiling; but the net brought up nothing very different from the creatures the man had already seen. The man listened for thunder but heard nothing but liquid rushing along the skin sides of the vessel. Once more T'Nekku spotted a large fish and with the aid of his harpoon indulged in what he insisted on translating as a snack. The native seemed to be taking everything with his usual perfect calm—of course, nothing had happened so far which either being could consider funny. His unconcern was infectious, but finally Cunningham began to wonder why their approach to the base of the cloud was so slow. He had formed an idea of their distance and the speed of the boat. Finally he mentioned the matter. "I was noticing that too," the native replied. "It seems a current is setting against us. This will be helpful in getting away, if we need it; I could lower all sail and cover up completely, then let it carry us out of reach of the light." "Of course. I should have expected this," replied Cunningham. "The heat wouldn't be coming up in just one spot. Thousands of square miles of ocean bottom must be hotter than the rest of the crust—the whole slope of this mountain whose top must be the island. Ammonia would be rising along its whole surface and spreading out in all directions—there would be this current fighting us no matter which direction we came from. Do you see?" "Of course. It is quite logical," boomed T'Nekku. For just a moment, the man wondered whether a quaver of humor were in his voice, but he did not pursue the thought. He might have done so, but the cloud ahead suddenly distracted him. For the hour or two since they had first seen it, the lightning—or at least, the flickering illumination which the man was attributing to lightning—had been incessant. Now, abruptly, the cloud went dark. Cunningham had been facing the stem as he spoke to T'Nekku, but the drop in light showed plainly on the sea which was in his field of view. He whirled about to see what was happening. There was little to see; the cloud remained, silhouetted against the stars, but after a few dying flickers its own light was gone. "I thought you said that would be a permanent display—that it had been going on for millions of days and would go on for millions more," remarked T'Nekku. "You implied that the death-light coming from it was the energy source for our food." "So I said. So I thought. I seem to have been at least partly wrong. Are you willing to sail straight in toward the cloud, now that the light is gone, to make sure whether there really is an island? I admit I can't even guess, now, when or whether the light is apt to start up again; and there is no doubt that it will get hotter as we approach." "Your life is here with mine," replied the giant calmly. "If I die, you could not get back to the trading post—you could neither handle the rigging nor find the place. If you want to take the risk, I am ready." "All right, then. Straight in toward the cloud. I am wondering whether it will dissipate, now that the lightning has ended." "I should think not. The heat is still there, as I can feel and as your thermometer has reported," the other pointed out. "There should still be vapor rising, even though whatever made the light has failed." "Hmph. Maybe. I'm beginning to doubt all my reasoning. There's obviously something I'm not allowing for." T'Nekku's cultural background included a recognizable form of courtesy, so he did not make the obvious answer to this. He changed the subject. "I have seen numbers of small swimming things near us in the past few minutes. Shouldn't you cast your net again?" "I should." He did so. Unfortunately, the small swimmers had no difficulty in avoiding the net. T'Nekku, mounting it on a harpoon shaft and using it as a dip net, was a little more successful; but mere gross inspection of the resulting specimens did nothing either way for Cunningham's theory. They seemed to be as much animals as T'Nekku himself, equipped to catch and eat other animals. They were not, as far as the man could tell, even plankton feeders. And there was still no visible plankton in the net. About this time, though, Cunningham managed to restore T'Nekku's sagging faith in human logic by making a prediction before the event. "With a warm water—excuse me, ammonia—current flowing out, and cold wind coming in, I should think we'd hit surface fog before long," the man remarked thoughtfully. "I hope you'll still be able to see. I wish I knew what wave lengths your eyes, if they are eyes, use." "If those waves pierced the fog you fear, would I be able to see that cloud we have been watching?" asked T'Nekku. Cunningham frowned thoughtfully and raised his converter goggles for a moment. He was then able to answer. "It would seem that you can. The fog is here. My flash goes through it all right, and you didn't even know it was there, but the cloud scatters light you can see. I wonder what's up there—maybe snowflakes? Or full-sized raindrops? I'll have to make a pass through it later with my own ship. Maybe I should have done that first." He shrugged and made another temperature check. "Warmer than ever. I'm surprised you can stand it." The native dipped a hand overside and hastily snatched it back. "I can't. The wind is what's keeping me comfortable now, I guess, unless you have a more logical explanation." "Do you think we should go any farther in?" T'Nekku rose suddenly to his feet. Cunningham tried to see where his harpoon was pointing, then realized that the giant was not holding his weapon. There was no way to tell where he was looking, and the man swung his flash around wildly in hopes of seeing for himself whatever had caught the pilot's attention. He saw nothing, of course—the beam lacked any real range—but T'Nekku spoke. "It won't be possible to go farther. I can see wave, breaking on each side of us; we're practically aground now!" The rumbling voice was calm, but its owner was active. The sail came down; the helm went over. "I don't want to get farther in, and tacking out would take us too near those breakers. We'll use the current." Cunningham stared but could still see nothing—even the nebula and stars were hidden by the fog now. The cloud had been distant when he last saw it; the island must be big. At least, it was now established that there was an island; he had been starting to doubt even that. Would there be any way for T'Nekku to set him ashore, in accordance with the original plan and agreement? The native had started to sheer off without any consultation. Had he seen something he was really afraid of? "If there are no waves ahead, Nek, maybe we can land. Couldn't you show just a little sail and just creep in here?" asked the man. 'We are going in anyway," was the rumbling reply. "The current has changed, and it has carried us through the gap in the breakers. Do you have a reasonable explanation?" "A river mouth—no, that would take us out. Rivers don't flow inland on small islands, and there's no tide on this planet. A deep bay, I suppose, but why the current—maybe it will get us closer to the center; the stuff must be going somewhere, and then—oh, blast, can you—" Cunningham didn't finish organizing his thoughts. He heard the grating sound as the keel struck bottom, but even if he had interpreted it correctly he could not have reacted in time. Inertia swept him gently but firmly over the bow. He made a snatch at the sprit and felt his glove touch some part of the rigging, but he got no grip. Bone-chilling liquid closed over his head. He wondered as he sank why he had never even thought of wearing flotation gear on this trip. No one could swim in liquid ammonia—even if he were protected from the temperature; its density was too low—one might as well try to swim in gasoline. At Omituinen's surface pressure, ammonia boils at about ten below zero, and the sea at this point was almost boiling, fortunately for Laird Cunningham. As it was, even through his airsuit's insulation he was shocked by the sudden chill. There was no breathing problem, of course, but— He struck bottom. Even counting the keel, the draft of T'Nekku's sailboat was small, and the water was shallow. The man got his feet under him and sprang upward as hard as he could, almost stunning himself on the bottom of the boat. He was helpless for a second or two; then he rose more carefully, hands above his head. He touched the hull before his knees were straight, this time; it must be sliding forward, so he was under the midship section rather than the bow—no, it was pressing down on him! It must be sinking! He had dropped his flash and could see nothing, but he could feel. With frantic haste he groped his way, following the sharpest upward curve he could find. It took perhaps half a minute to get out from underneath, but it seemed much longer. He stood up and found his head above the surface. It had been deeper than that where he fell—or had it? He had fallen in an awkward, crumpled position—but he had not struck his head on the hull until his feet were of the bottom, on that leap—what was happening, anyway? He heard T'Nekku's voice thundering his name and tried to answer, but the speaking diaphragms of his face mask were not clear yet, and only an inarticulate sputtering emerged. The liquid was down to his shoulders. To his armpits His chest. He reached around, found the hull, and felt it move slowly away from him—it was tipping. That oriented him. The keel had struck bottom, hurling him overboard, because the ocean had started to withdraw. The boat was right where it had struck but was heeling over as the supporting ammonia disappeared from under it. Thoughts of tsunamis flashed across Cunningham's mind—they were too close to land to survive the high side of such a wave. It would break over them—would T'Nekku know what to do? Could he do anything? Or was this something other than a tsunami—something strictly native to Omituinen, beyond the man's experience? He was only waist-deep now. His speakers should have drained. "Nek! Are you all right?" he called. "Somewhat upset, but not hurt," was the calm answer. "How is it that you are alive? I saw you go overboard and assumed you would die at once." "Your ocean isn't all that different from your air, as far as my suit and I are concerned," Cunningham pointed out. "The real worry is how long either of us can stay alive. The water—excuse me, ammonia—is draining away somewhere, and even you won't last long around here with your boat high and dry." "True. We must think. At least, this draining away explains the onshore current that caught us." "I suppose so, but I'd like to know what explains the draining. Even if there's some sort of crater in the island that isn't full, which is hard to believe, why isn't ocean still coming in after us?" The man was only knee-deep in ammonia by this time, and he began to splash his way around to the low side of the hull. As he passed the bow his foot struck something he recognized, and with great relief he picked up his flash, sweeping its beam along the tilted vessel to see what had happened. T'Nekku was just stepping out over the submerged port gunwale. The boat had, of course, filled the moment this side had gone under. As far as the man could tell neither T'Nekku's personal supplies nor his own equipment had shifted seriously, but the fact remained that the vessel was not only solidly aground but also, for the moment at least, an unknown distance inland. Its owner remained calm, of course, and Cunningham tried to imitate him. He had always known, naturally, that his retirement would in some drastic fashion come sooner or later; everyone's did. He was not, however, prepared to resign himself to the notion that this must be the time. "We'd better find out how far away the ocean is now, if you want to take the chance," he suggested. "What chance?" asked the native. "I see no risk in walking back toward the ocean." "What has just happened reminds me of a huge wave I have known of on other worlds, whose low side comes first. If that is what is happening here, the high side will be along shortly, and you might be caught away from the boat." "What good would the boat do me now?" asked T'Nekku practically. "Hmph. That's a point. Well, if we could get it righted and emptied, there's a chance it would float when the wave comes in." The giant pondered this for a moment. "Righting it should not take long," he said at length. "This sand feels firm but should dig easily." One of his broad feet demonstrated briefly. "If we dig it away under the keel, which is all that is holding the hull tipped, she should settle back on her bottom easily enough." "All right; but maybe we'd better do that before you go exploring." "Frankly, I am very curious. Also, the walk may show that digging would be a waste of time—that something else would be more advisable. I suggest that I go to find the sea while you start the digging. I should be back quickly." It never occurred to Cunningham to suspect his companion of laziness, so he took the suggestion at face value. "All right, I guess. What do you have that I can use for digging?" "Why, your hand—but you have only two, of course. I hadn't thought of that. How about one of my spare harpoons?" Cunningham sighed again. "If that's what you have, it will have to do. Let's have it—and please find that ocean as soon as you can." Work in even the most flexible and pressure-balanced airsuits, under extra gravity, would not be easy. Cunningham knew this before he started. But he did hope it would be possible. With the native out of sight, he made his way back around to the starboard side with the uncomfortably heavy harpoon, set his light on the ground so that it would illuminate the work area and began scraping sand from under the keel. It was not too difficult, at that. Within a few minutes the keel settled half an inch into the groove he had made under it. Of course, as he went deeper there would be more sand to move—the third-power law was against him. However, T'Nekku should be back before long. Also, as he recalled from similar beach-digging experience during his childhood, he would probably reach the liquid table quickly, and the saturated sand should practically flow out from under the pressure of the keel. It was hardly possible for a granular surface which had been submerged only minutes before to be anything but saturated at any real distance below its surface. But this idea did not work out. Another inch, and yet another, the keel settled. Each inch brought the hull a little closer to upright, but the firm dampness of the sand did not change. As an experiment, Cunningham left the job long enough to dig a cylindrical hole straight down for about two feet. The sand was firm enough to permit vertical sides to the little well, but its bottom showed no signs of filling. Curious now, he shuffled around to the other side of the hull and scooped a specimen-bucket of the ammonia it contained out onto the sand. It disappeared with surprising speed. He carried another bucketful around to his hole and poured it in; here, too, it soaked in instantly. He was really puzzled now, but worked and thought simultaneously. Once he stopped as an idea struck him; he returned to his equipment supply, found a length of flexible tubing and rigged a siphon to start emptying the hull. Unfortunately, the hose was not long enough to let him use the stream as a digging tool where it was needed. He continued to dig and puzzle. This sand was firmly packed, and he had never heard that ammonia was very much less viscous than water; how did the liquid soak in so fast? And where did it go? He did not hear T'Nekku approach, but the giant was suddenly looming beside him. "It is not one of your waves," the native boomed. "The bottom seems to have risen just enough to cut the sea off from this bay—just barely enough—some waves are splashing over, but they sink in before getting this far. If it had only happened a few minutes earlier, we would be safe outside." "I hate to sound paranoid," said Cunningham thoughtfully, "but usually in the past when the timing has been that good it has been deliberate. I've seen no other sign of life here, though." "Could it be something that happens at regular intervals, rather than just once, or randomly? I would find the whole matter less surprising." "I don't know. With neither a sun nor a moon, you don't have tides here. Wait, though, maybe it could. I've just remembered something—let's see. Heat from below, which we're taking for granted; regular water—ammonia—supply; liquid flows down, very rapidly in this case, gets heated but can't boil at first because of pressure due to depth—yes. It could be. This would be the biggest geyser I've ever seen or heard of, but that doesn't make it impossible. I don't see why the shore should rise, though—maybe gas pressure as heat accumulates—I don't know. It's a good idea, and we can work out details later. The real question, if it's basically right, is what period we can expect? Also, if the dam behind us does go down again, what will keep us from being washed downstream toward whatever reservoir this geyser uses? We'd have to claw your boat out against quite a current and against the wind." "We could leave and build another, supposing there are animals on this island big enough to provide bone and skin. Or we could take this one apart, get the pieces to safety and rebuild it at our leisure." "Would that be possible? What if the river came in while we had it too far apart to float but not carried to safety?" He paused in thought for a moment. "How about getting it upright and floatable and then waiting through a cycle of this thing—or at least long enough to suggest the cycle will be too long for us. If the river comes in, we can't fight it, but I should think you could guide us to one side and ground there, or anchor. Then we'd know we were close to a safe spot, and we'd know about how long we'd have to do the dismantling and rebuilding. Can you stand the heat here, just waiting?" "As long as the wind blows, yes. The sand is uncomfortable. but once the boat is level I can stay in that. I can't say your plan really satisfies me, but I can think of nothing better. Let's get on with the digging. What's this hole you made, with liquid in the bottom? Wasn't there enough in the boat already?" Cunningham was slow to react. "I noticed how quickly the liquid soaked into the sand and was trying to find how far down the table was. I still don't see how it disappears so fast. I wish I knew the viscosity of ammonia—but even if it's ten or a hundred times that of water, where did—What? Did you say there is liquid in the hole?" "Yes. Look." Cunningham shone his flash downward. The well had mushroomed at the bottom, like the holes he had dug in an Earthly beach so long ago, as sand from the walls settled into the liquid to form a loose slurry. As he watched, another lump fell and lost its identity. He reached down with his gloved hand and scooped up some of the sand-and-liquid mixture, bringing it and his face both toward the light. "It's warm, even for me!" he exclaimed. T'Nekku extended a hand toward it, then withdrew the member in startled haste, ejaculating an indescribable sound. "What a stink! That's not sea-ammonia! What do you have there, anyway?" The man looked up, frowning. "It's not? You're sure?" "I never dipped a finger into a smell like that in my life, and I will never willingly do it again!" Cunningham thought for half a minute. Then he got to his feet as quickly as the gravity permitted and shuffled hastily around the bow toward his specimen containers, still cupping the offensive stuff in his hand. He called back over his shoulder, "Dig like mad! Get this boat upright! And when we've managed that, keep on digging—I want to see what's under this sand!" Two hours later and a mile offshore, with the beginning flickers of lightning playing on the looming cloud, Cunningham spoke more calmly. "It all makes perfectly good sense, though I wish we'd had more time to dig. I'm sure I know what we would have found. I was just being trapped by my own prejudices, as usual. I was looking for microscopic life which could fix Omituinen's atmospheric nitrogen and produce the basic food compounds which you find so distasteful in concentrated form. I'd be surprised at that if I hadn't had to live on straight amino acids for a while, once. When I saw the lightning, I was sure its high-energy quanta must be the key. But I didn't stop to think how little of the total available energy was going into that lightning, and what a big advantage would be possessed by a life form able to use the heat directly, for anabolism. I just never thought of the possibility of a single huge plant underlying—practically forming—the island. I had to be slammed on the nose—and underfoot—by it. The geyser idea was good but left out some facts that needed explaining." "I suppose you know what you're talking about, and that awful-smelling stuff is what I basically live on," rumbled 'T'Nekku, "but I'll keep taking it in meat, I think. I still don't see, though, what led you to think of a single big creature, even when the food appeared in that well. "I can see now how it must have got there. The creature must be only a little way down, to take in ammonia from the river so fast and get the waste products back so quickly—but why a single creature? Why not millions of the little things you expected, living among the sand grains?" The man smiled. "It wasn't the stuff in the hole. Then is a process carried out by many organisms—though not, in my experience, by plants—which you would have no way of knowing about. You get all your food chemically by eating and drinking. It was the changing height of the ground, alternately raising and lowering the sandbar which shut us off from the sea, which was the real clue. I'm afraid I never explained breathing to you." He did. "It does make sense," the 'Tuinainen admitted. "This would mean, then, that every hot place in the world is surrounded by a creature of this sort, living on the heat and putting out chemicals which are food for real people." "Possibly." Cunningham was hesitant as a new thought struck him. "I can't tell, or more than guess, whether the others would be just like this one. Maybe—hmmm. It's hard to say whether the word species would mean anything in this connection. Maybe each one developed individually—or from cells shed by others—but modified as it developed. Plants differ in individual characteristics more than animals, at least on worlds I know ..." His voice trailed off, and he thought silently for a minute or two. "Nek, are you willing to go back to your island, lay in a really huge supply for me and then go on a long journey? Would more of your people get in on the act, if I told what I've found and some other off-worlder came to investigate?" "I will be quite willing to listen to reason," the giant assured him.