At the same moment that resourceful individual was taking stock of the situation, which might very well have been worse. He had reached the hills in three jumps and felt less naked than he had out in the open plain. The food and equipment he had taken from the ship he had hidden where he hoped he could find it again, but since his suit could keep him alive for over a day that was the least of his worries. The small packet that was the cause of all the trouble was still with him, in one of those numerous hiding places a well-designed space suit affords.

  There was an exhilarating loneliness about his mountain eyrie, even though he was not quite as lonely as he would have wished. Forever fixed in his sky, Mars was waning almost visibly as Phobos swept above the night side of the planet. He could just make out the lights of some of the Martian cities, gleaming pin points marking the junctions of the invisible canals. All else was stars and silence and a line of jagged peaks so close it seemed he could almost touch them. Of the Doradus there was still no sign. She was presumably carrying out a careful telescopic examination of the sunlighted side of Phobos.

  Mars was a very useful clock: when it was half full the sun would rise and, very probably, so would the Doradus. But she might approach from some quite unexpected quarter: she might even—and this was the one real danger—she might even have landed a search party.

  This was the first possibility that had occurred to Com-

  mander Smith when he saw just what he was up against. Then he realized that the surface area of Phobos was over a thousand square kilometers and that he could not spare more than ten men from his crew to make a search of that jumbled wilderness. Also, K.15 would certainly be armed.

  Considering the weapons which the Doradus carried, this last objection might seem singularly pointless. It was very far from being so. In the ordinary course of business, side arms and other portable weapons are as much use to a space-cruiser as are cutlasses and crossbows. The Doradus happened, quite by chance—and against regulations at that—to carry one automatic pistol and a hundred rounds of ammunition. Any search party would therefore consist of a group of unarmed men looking for a well-concealed and very desperate individual who could pick them off at his leisure. K.15 was breaking the rules again.

  The terminator of Mars was now a perfectly straight line, and at almost the same moment the sun came up, not so much like thunder as like a salvo of atomic bombs. K.15 adjusted the filters of his visor and decided to move. It was safer to stay out of the sunlight, not only because here he was less likely to be detected in the shadow but also because his eyes would be much more sensitive there. He had only a pair of binoculars to help him, whereas the Doradus would carry an electronic telescope of twenty-centimeter aperture at least.

  It would be best, K.15 decided, to locate the cruiser if he could. It might be a rash thing to do, but he would feel much happier when he knew exactly where she was and could watch her movements. He could then keep just below the horizon, and the glare of the rockets would give him ample warning of any impending move. Cautiously launching himself along an almost horizontal trajectory, he began the circumnavigation of his world.

  The narrowing crescent of Mars sank below the horizon until only one vast horn reared itself enigmatically against the stars. K.15 began to feel worried: there was still no sign of the Doradus. But this was hardly surprising, for she was

  painted black as night and might be a good hundred kilometers away in space. He stopped, wondering if he had done the right thing after all. Then he noticed that something quite large was eclipsing the stars almost vertically overhead, and was moving swiftly even as he watched. His heart stopped for a moment: then he was himself again, analyzing the situation and trying to discover how he had made so disastrous a mistake.

  It was some time before he realized that the black shadow slipping across the sky was not the cruiser at all, but something almost equally deadly. It was far smaller, and far nearer, than he had at first thought. The Doradus had sent her television-homing guided missiles to look for him.

  This was the second danger he had feared, and there was nothing he could do about it except to remain as inconspicuous as possible. The Doradus now had many eyes searching for him, but these auxiliaries had very severe limitations. They had been built to look for sunlit spaceships against a background of stars, not to search for a man hiding in a dark jungle of rock. The definition of their television systems was low, and they could only see in the forward direction.

  There were rather more men on the chessboard now, and the game was a little deadlier, but his was still the advantage.

  The torpedo vanished into the night sky. As it was traveling on a nearly straight course in this low-gravitational field, it would soon be leaving Phobos behind, and K.15 waited for what he knew must happen. A few minutes later, he saw a brief stabbing of rocket exhausts and guessed that the projectile was swinging slowly back on its course. At almost the same moment he saw another flare far away in the opposite quarter of the sky, and wondered just how many of these infernal machines were in action. From what he knew of Z-class cruisers—which was a good deal more than he should—there were four missile-control channels, and they were probably all in use.

  He was suddenly struck by an idea so brilliant that he was quite sure it couldn't possibly work. The radio on his suit was

  a tunable one, covering an unusually wide band, and somewhere not far away the Doradus was pumping out power on everything from, a thousand megacycles upward. He switched on the receiver and began to explore.

  It came in quickly—the raucous whine of a pulse transmitter not far away. He was probably only picking up a sub-harmonic, but that was quite good enough. It D/F'ed sharply, and for the first time K.15 allowed himself to make long-range plans about the future. The Doradus had betrayed herself: as long as she operated her missiles, he would know exactly where she was.

  He moved cautiously forward toward the transmitter. To his surprise the signal faded, then increased sharply again. This puzzled him until he realized that he must be moving through a diffraction zone. Its width might have told him something useful if he had been a good-enough physicist, but he couldn't imagine what.

  The Doradus was hanging about five kilometers above the surface, in full sunlight. Her "nonreflecting" paint was overdue for renewal, and K.15 could see her clearly. Since he was still in darkness, and the shadow line was moving away from him, he decided that he was as safe here as anywhere. He settled down comfortably so that he could just see the cruiser and waited, feeling fairly certain that none of the guided projectiles would come so near the ship. By now, he calculated, the commander of the Doradus must be getting pretty mad. He was perfectly correct.

  After an hour, the cruiser began to heave herself round with all the grace of a bogged hippopotamus. K.15 guessed what was happening. Commander Smith was going to have a look at the antipodes, and was preparing for the perilous fifty-kilometer journey. He watched very carefully to see the orientation the ship was adopting, and when she came to rest again was relieved to see that she was almost broadside to him. Then, with a series of jerks that could not have been very enjoyable aboard, the cruiser began to move down to the horizon. K.15 followed her at a comfortable walking pace—

  if one could use the phrase—reflecting that this was a feat very few people had ever performed. He was particularly careful not to overtake her on one of his kilometer-long glides, and kept a close watch for any missiles that might be coming up astern.

  It took the Doradus nearly an hour to cover the fifty kilometers. This, as K.15 amused himself by calculating, represented considerably less than a thousandth of her normal speed. Once she found herself going off into space at a tangent, and rather than waste time turning end over end again fired off a salvo of shells to reduce speed. But she made it at last, and K.15 settled down for another vigil, wedged between two rocks where he could just see the cruiser and he was quite sure she couldn't see him. It occurred to him that by this time Commander Smith might have g
rave doubts as to whether he really was on Phobos at all, and he felt like firing off a signal flare to reassure him. However, he resisted the temptation.

  There would be little point in describing the events of the next ten hours, since they differed in no important detail from those that had gone before. The Doradus made three other moves, and K.15 stalked her with the care of a big-game hunter following the spoor of some elephantine beast. Once, when she would have led him out into full sunlight, he let her fall below the horizon until he could only just pick up her signals. But most of the time he kept her just visible, usually low down behind some convenient hill.

  Once a torpedo exploded some kilometers away, and K.15 guessed that some exasperated operator had seen a shadow he didn't like—or else that a technician had forgotten to switch off a proximity fuse. Otherwise nothing happened to enliven the proceedings: in fact, the whole affair was becoming rather boring. He almost welcomed the sight of an occasional guided missile drifting inquisitively overhead, for he did not believe that they could see him if he remained motionless and in reasonable cover. If he could have stayed on the part of Phobos exactly opposite the cruiser he would have been safe even from these, he realized, since the ship would

  have no control there in the moon's radio-shadow. But he could think of no reliable way in which he could be sure of staying in the safety zone if the cruiser moved again.

  The end came very abruptly. There was a sudden blast of steering jets, and the cruiser's main drive burst forth in all its power and splendor. In seconds the Doradus was shrinking sunward, free at last, thankful to leave, even in defeat, this miserable lump of rock that had so annoyingly balked her of her legitimate prey. K.15 knew what had happened, and a great sense of peace and relaxation swept over him. In the radar room of the cruiser, someone had seen an echo of disconcerting amplitude approaching with altogether excessive speed. K.15 now had only to switch on his suit beacon and to wait. He could even afford the luxury of a cigarette.

  "Quite an interesting story," I said, "and I see now how it ties up with that squirrel. But it does raise one or two queries in my mind."

  "Indeed?" said Rupert Kingman politely.

  I always like to get to the bottom of things, and I knew that my host had played a part in the Jovian War about which he very seldom spoke. I decided to risk a long shot in the dark.

  "May I ask how you happen to know so much about this unorthodox military engagement? It isn't possible, is it, that you were K.15?"

  There was an odd sort of strangling noise from Carson. Then Kingman said, quite calmly: "No, I wasn't."

  He got to his feet and went off toward the gun room.

  "If you'll excuse me a moment, I'm going to have another shot at that tree-rat. Maybe I'll get him this time." Then he was gone.

  Carson looked at me as if to say: "This is another house you'll never be invited to again." When our host was out of earshot he remarked in a coldly cynical voice:

  "You've done it. What did you have to say that for?"

  "Well, it seemed a safe guess. How else could he have known all that?"

  "As a matter of fact, I believe he met K.15 after the War: they must have had an interesting conversation together. But I thought you knew that Rupert was retired from the service with only the rank of lieutenant commander. The Court of Inquiry could never see his point of view. After all, it just wasn't reasonable that the commander of the fastest ship in the Fleet couldn't catch a man in a space suit."

  London August 1948

  Out of the Sun

  If you have only lived on Earth, you have never seen the sun. Of course, we could not look at it directly, but only through dense filters that cut its rays down to endurable brilliance. It hung there forever above the low, jagged hills to the west of the Observatory, neither rising nor setting, yet moving around a small circle in the sky during the eighty-eight-day year of our little world. For it is not quite true to say that Mercury keeps the same face always turned toward the sun; it wobbles slightly on its axis, and there is a narrow twilight belt which knows such terrestrial commonplaces as dawn and sunset.

  We were on the edge of the twilight zone, so that we could take advantage of the cool shadows yet could keep the sun under continuous surveillance as it hovered there above the hills. It was a full-time job for fifty astronomers and other assorted scientists; when we've kept it up for a hundred years or so, we may know something about the small star that brought life to Earth.

  There wasn't a single band of solar radiation that someone at the Observatory had not made a life's study and was watching like a hawk. From the far X rays to the longest of radio waves, we had set our traps and snares; as soon as the

  sun thought of something new, we were ready for it. So we imagined. . . .

  The sun's flaming heart beats in a slow, eleven-year rhythm, and we were near the peak of the cycle. Two of the greatest spots ever recorded—each of them large enough to swallow a hundred Earths—had drifted across the disk like great black funnels piercing deeply into the turbulent outer layers of the sun. They were black, of course, only by contrast with the brilliance all around them; even their dark, cool cores were hotter and brighter than an electric arc. We had just watched the second of them disappear around the edge of the disk, wondering if it would survive to reappear two weeks later, when something blew up on the equator.

  It was not too spectacular at first, partly because it was almost exactly beneath us—at the precise center of the sun's disk—and so was merged into all the activity around it. If it had been near the edge of the sun, and thus projected against the background of space, it would have been truly awe-inspiring.

  Imagine the simultaneous explosion of a million H bombs. You can't? Nor can anyone else—but that was the sort of thing we were watching climb up toward us at hundreds of miles a second, straight out of the sun's spinning equator. At first it formed a narrow jet, but it was quickly frayed around the edges by the magnetic and gravitational forces that were fighting against it. The central core kept right on, and it was soon obvious that it had escaped from the sun completely and was headed out into space—with us as its first target.

  Though this had happened half a dozen times before, it was always exciting. It meant that we could capture some of the very substance of the sun as it went hurtling past in a great cloud of electrified gas. There was no danger; by the time it reached us it would be far too tenuous to do any damage, and, indeed, it would take sensitive instruments to detect it at all.

  One of those instruments was the Observatory's radar,

  which was in continual use to map the invisible ionized layers that surround the sun for millions of miles. This was my department; as soon as there was any hope of picking up the oncoming cloud against the solar background, I aimed my giant radio mirror toward it.

  It came in sharp and clear on the long-range screen—a vast, luminous island still moving outward from the sun at hundreds of miles a second. At this distance it was impossible to see its finer details, for my radar waves were taking minutes to make the round trip and to bring me back the information they were presenting on the screen. Even at its speed of not far short of a million miles an hour, it would be almost two days before the escaping prominence reached the orbit of Mercury and swept past us toward the outer planets. But neither Venus nor Earth would record its passing, for they were nowhere near its line of flight.

  The hours drifted by; the sun had settled down after the immense convulsion that had shot so many millions of tons of its substance into space, never to return. The aftermath of that eruption was now a slowly twisting and turning cloud a hundred times the size of Earth, and soon it would be close enough for the short-range radar to reveal its finer structure.

  Despite all the years I have been in the business, it still gives me a thrill to watch that line of light paint its picture on the screen as it spins in synchronism with the narrow beam of radio waves from the transmitter. I sometimes think of myself as a blind man exploring
the space around him with a stick that may be a hundred million miles in length. For Man is truly blind to the things I study; these great clouds of ionized gas moving far out from the sun are completely invisible to the eye and even to the most sensitive of photographic plates. They are ghosts that briefly haunt the Solar System during the few hours of their existence; if they did not reflect our radar waves or disturb our magnetometers, we should never know that they were there.

  The picture on the screen looked not unlike a photograph of a spiral nebula, for as the cloud slowly rotated it trailed

  ragged arms of gas for ten thousand miles around it. Or it might have been a terrestrial hurricane that I was watching from above as it spun through the atmosphere of Earth. The internal structure was extremely complicated, and was changing minute by minute beneath the action of forces which we have never fully understood. Rivers of fire were flowing in curious paths under what could only be the influence of electric fields; but why were they appearing from nowhere and disappearing again as if matter was being created and destroyed? And what were those gleaming nodules, larger than the Moon, that were being swept along like boulders before a flood?

  Now it was less than a million miles away; it would be upon us in little more than an hour. The automatic cameras were recording every complete sweep of the radar scan, storing up evidence which was to keep us arguing for years. The magnetic disturbance riding ahead of the cloud had already reached us; indeed, there was hardly an instrument in the Observatory that was not reacting in some way to the onrushing apparition.

  I switched to the short-range scanner, and the image of the cloud expanded so enormously that only its central portion was on the screen. At the same time I began to change frequency, tuning across the spectrum to differentiate among the various levels. The shorter the wave length, the farther you can penetrate into a layer of ionized gas; by this technique I hoped to get a kind of X-ray picture of the cloud's interior.