The Space Trilogy

by Arthur C. Clarke

  Merton smiled as he read the message.

  "Just like Maclaurin. Instruments first, staff second. I'm not too worried. I'll do my damnedest to miss him. A hundred kilometres isn't a bad safety margin, when you come to think of it. Unless there's a direct hit with a stray, they've nothing to worry about. They're pretty well dug in, you know."

  The relentless hand of the chronometer was scything away the last minutes. Still confident that his ship, encased in its cocoon of night, had not yet been detected, Commodore Brennan watched the three sparks of his fleet creep along their appointed tracks in the plotting sphere. This was not a destiny he had ever imagined would be his—to hold the fate of worlds within his hands.

  But he was not thinking of the powers that slumbered in the reactor banks, waiting for his command. He was not concerned with the place he would take in history, when men looked back upon this day. He only wondered, as had all who had ever faced battle for the first time, where he would be this same time tomorrow.

  Less than a million kilometres away, Carl Steffanson sat at a control desk and watched the image of the sun, picked up by one of the many cameras that were the eyes of Project Thor. The group of tired technicians standing around him had almost completed the equipment before his arrival; now the discriminating units he had brought from Earth in such desperate haste had been wired into the circuit.

  Steffanson turned a knob, and the sun went out. He flicked from one camera position to another, but all the eyes of the fortress were equally blind. The coverage was complete.

  Too weary to feel any exhilaration, he leaned back in his seat and gestured toward the controls.

  "It's up to you now. Set it to pass enough light for vision, but to give total rejection from the ultra-violet upward. We're sure none of their beams carry any effective power much beyond a thousand Angstroms. They'll be very surprised when all their stuff bounces off. I only wish we could send it back the way it came."

  "Wonder what we look like from outside when the screen's on?" said one of the engineers.

  "Just like a perfectly reflecting mirror. As long as it keeps reflecting, we're safe against pure radiation. That's all I can promise you."

  Steffanson looked at his watch.

  "If Intelligence is correct, we have about twenty minutes to spare. But I shouldn't count on it."

  "At least Maclaurin knows where we are now," said Jamieson as he switched off the radio. "But I can't blame him for not sending someone to pull us out."

  "Then what do we do now?"

  "Get some food," Jamieson answered, walking back to the tiny galley. "I think we've earned it, and there may be a long walk ahead of us."

  Wheeler looked nervously across the plain, to the distant but all too clearly visible dome of Project Thor. Then his jaw dropped and it was some seconds before he could believe that his eyes were not playing tricks on him.

  "Sid!" he called. "Come and look at this!"

  Jamieson joined him at a rush, and together they stared out toward the horizon. The partly shadowed hemisphere of the dome had changed its appearance completely. Instead of a thin crescent of light, it now showed a single dazzling star, as though the image of the sun was being reflected from a perfectly spherical mirror surface.

  The telescope confirmed this impression. The dome itself was no longer visible; its place seemed to have been taken by this fantastic silver apparition. To Wheeler it looked exactly like a great blob of mercury sitting on the skyline.

  "I'd like to know how they've done that," was Jamieson's un-excited comment. "Some kind of interference effect, I suppose. It must be part of their defence system."

  "We'd better get moving," said Wheeler anxiously. "I don't like the look of this. It feels horribly exposed up here."

  Jamieson had started throwing open cupboards and pulling out stores. He tossed some bars of chocolate and packets of compressed meat over to Wheeler.

  "Start chewing some of this," he said. "We won't have time for a proper meal now. Better have a drink as well, if you're thirsty. But don't take too much—you'll be in that suit for hours, and these aren't luxury models."

  Wheeler was doing some mental arithmetic. They must be about eighty kilometres from base, with the entire rampart of Plato between them and the Observatory. Yes, it would be a long walk home, and they might after all be safer here. The tractor, which had already served them so well, could protect them from a good deal of trouble.

  Jamieson toyed with the idea, but then rejected it. "Remember what Steffanson said," he reminded Wheeler. "He told us to get underground as soon as we could. And he must know what he's talking about."

  They found a crevasse within fifty meters of the tractor, on the slope of the ridge away from the fortress. It was just deep enough to see out of when they stood upright, and the floor was sufficiently level to lie down. As a slit trench, it might almost have been made to order, and Jamieson felt much happier when he had located it.

  "The only thing that worries me now," he said, "is how long we may have to wait. It's still possible that nothing will happen at all. On the other hand, if we start walking we may be caught in the open away from shelter."

  After some discussion, they decided on a compromise. They would keep their suits on, but would go back and sit in Ferdinand where at least they would be comfortable. It would take them only a few seconds to get to the trench.

  There was no warning of any kind. Suddenly the gray, dusty rocks of the Sea of Rains were scorched by a light they had never known before in all their history. Wheeler's first impression was that someone had turned a giant searchlight full upon the tractor; then he realized that this sun-eclipsing explosion was many kilometres away. High above the horizon was a ball of violet flame, perfectly spherical, and rapidly losing brilliance as it expanded. Within seconds, it had faded to a great cloud of luminous gas. It was dropping down toward the edge of the Moon, and almost at once had sunk below the skyline like some fantastic sun.

  "We were fools," said Jamieson gravely. "That was an atomic warhead—we may be dead men already."

  "Nonsense," retorted Wheeler, though without much confidence. "That was fifty kilometres away. The gammas would be pretty weak by the time they reached us—and these walls aren't bad shielding."

  Jamieson did not answer; he was already on his way to the airlock. Wheeler started to follow him, then remembered that there was a radiation detector aboard and went back to collect it. Was there anything else that might be useful while he was here? On a sudden impulse, he jerked down the curtain-rod above the little alcove that concealed the lavatory, then ripped away the wall mirror over the sink.

  When he joined Jamieson, who was waiting impatiently for him in the airlock, he handed over the detector, but did not bother to explain the rest of his equipment. Not until they had settled down in their trench, which they reached without further incident, did he make its purpose clear.

  "If there's one thing I hate," he said petulantly, "it's not being able to see what's going on." He started to fix the mirror to the curtain rod, using some wire from one of the pouches round his suit. After a couple of minutes' work, he was able to hoist a crude periscope out of the hole.

  "I can just see the dome," he said with some satisfaction. "It's quite unchanged, as far as I can tell."

  "It would be," Jamieson replied. "They must have managed to explode that bomb somehow while it was miles away."

  "Perhaps it was only a warning shot."

  "Not likely! No one wastes plutonium for firework displays. That meant business. I wonder when the next move is going to be?"

  It did not come for another five minutes. Then, almost simultaneously, three more of the dazzling atomic suns burst against the sky. They were all moving on trajectories that took them toward the dome, but long before they reached it they had dispersed into tenuous clouds of vapour.

  "Rounds one and two to Earth," muttered Wheeler. "I wonder where these missiles are coming from?"

  "If any of them burst directl
y overhead," said Jamieson, "we will be done for. Don't forget that there's no atmosphere to absorb the gammas here."

  "What does the radiation meter say?"

  "Nothing much yet, but I'm worried about that first blast, when we were still in the tractor."

  Wheeler was too busily searching the sky to answer. Somewhere up there among the stars, which he could see now that he was out of the direct glare of the sun, must be the ships of the Federation, preparing for the next attack. It was not likely that the ships themselves would be visible, but he might be able to see their weapons in action.

  From somewhere beyond Pico, six sheaves of flame shot up into the sky at an enormous acceleration. The dome was launching its first missiles, straight into the face of the sun. The Lethe and the Eridanus were using a trick as old as warfare itself: they were approaching from a direction in which their opponent would be partly blinded. Even radar could be distracted by the background of solar interference, and Commodore Brennan had enlisted two large sunspots as minor allies.

  Within seconds, the rockets were lost in the glare. Minutes seemed to pass; then the sunlight abruptly multiplied itself a hundredfold. The folks up on Earth, thought Wheeler as he readjusted the filters of his visor, will be having a grandstand view tonight. And the atmosphere which is such a nuisance to astronomers will protect them from anything that these warheads can radiate.

  There was no way to tell if the missiles had done any damage. That enormous and soundless explosion might have dissipated itself harmlessly into space. This would be a strange battle, he realized. He might never even see the Federation ships, which would almost certainly be painted as black as night to make them undetectable.

  Then he saw that something was happening to the dome. It was no longer a gleaming spherical mirror reflecting only the single image of the sun. Light was splashing from it in all directions, and its brilliance was increasing second by second. From somewhere out in space, power was being poured into the fortress. That could only mean that the ships of the Federation were floating up there against the stars, beaming countless millions of kilowatts down upon the Moon. But there was still no sign of them, for there was nothing to reveal the track of the river of energy pouring invisibly through space.

  The dome was now far too bright to look upon directly, and Wheeler readjusted his filters. He wondered when it was going to reply to the attack, or indeed if it could do so while it was under this bombardment. Then he saw that the hemisphere was surrounded by a wavering corona, like some kind of brush discharge. Almost at the same moment, Jamieson's voice rang in his ears.

  "Look, Con—right overhead!"

  He glanced away from the mirror and looked directly into the sky. For the first time, he saw one of the Federation ships. Though he did not know it, he was seeing the Acheron, the only spaceship ever to be built specifically for war. It was clearly visible, and seemed remarkably close. Between it and the fortress, like an impalpable shield, flared a disk of light which as he watched turned cherry-red, then blue-white, then the deadly searing violet seen only in the hottest of the stars. The shield wavered back and forth, giving the impression of being balanced by tremendous and opposing energies. As Wheeler stared, oblivious to his peril, he saw that the whole ship was surrounded by a faint halo of light, brought to incandescence only where the weapons of the fortress tore against it.

  It was some time before he realized that there were two other ships in the sky, each shielded by its own flaming nimbus. Now the battle was beginning to take shape; each side had cautiously tested its defences and its weapons, and only now had the real trial of strength begun.

  The two astronomers stared in wonder at the moving fireballs of the ships. Here was something totally new—something far more important than any mere weapon. These vessels possessed a means of propulsion which must make the rocket obsolete. They could hover motionless at will, then move off in any direction at a high acceleration. They needed this mobility; the fortress, with all its fixed equipment, far out-powered them and much of their defence lay in their speed.

  In utter silence, the battle was rising to its climax. Millions of years ago the molten rock had frozen to form the Sea of Rains, and now the weapons of the ships were turning it once more to lava. Out by the fortress, clouds of incandescent vapour were being blasted into the sky as the beams of the attackers spent their fury against the unprotected rocks. It was impossible to tell which side was inflicting the greater damage. Now and again a screen would flare up, as a 'flicker of heat passes over white-hot steel. When that happened to one of the battleships, it would move away with that incredible acceleration, and it would be several seconds before the focusing devices of the fort had located it again.

  Both Wheeler and Jamieson were surprised that the battle was being fought at such short ranges. There was probably never more than a hundred kilometres between the antagonists, and usually it was much less than this. When one fought with weapons that travelled at the speed of light—indeed, when one fought with light itself—such distances were trivial.

  The explanation did not occur to them until the end of the engagement. All radiation weapons have one limitation: they must obey the law of inverse squares. Only explosive missiles are equally effective from whatever range they have been projected: if one is hit by an atomic bomb, it makes no difference whether it has travelled ten kilometres or a thousand.

  But double the distance of any kind of radiation weapon, and you divide its power by four owing to the spreading of the beam. No wonder, therefore, that the Federal commander was coming as close to his objective as he dared.

  The fort, lacking mobility, had to accept any punishment the ships could give it. After the battle had been on for a few minutes, it was impossible for the unshielded eye to look anywhere toward the south. Ever and again the clouds of rock vapour would go sailing up into the sky, falling back on the ground like luminous steam. And presently, as he peered through his darkened goggles and manoeuvred his clumsy periscope, Wheeler saw something he could scarcely believe. Around the base of the fortress was a slowly spreading circle of lava, melting down ridges and even small hillocks like lumps of wax.

  That awe-inspiring sight brought home to him, as nothing else had done, the frightful power of the weapons that were being wielded only a few kilometres away. If even the merest stray reflection of those energies reached them here, they would be snuffed out of existence as swiftly as moths in an oxy-hydrogen flame.

  The three ships appeared to be moving in some complex tactical pattern, so that they could maintain the maximum bombardment of the fort while reducing its opportunity of striking back. Several times one of the ships passed vertically overhead, and Wheeler retreated as far into the crack as he could in case any of the radiation scattered from the screens splashed down upon them. Jamieson, who had given up trying to persuade his colleague to take fewer risks, had now crawled some distance along the crevasse, looking for a deeper part, preferably with a good overhang. He was not so far away, however, that the rock was shielding the suit-radios, and Wheeler gave him a continuous commentary on the battle.

  It was hard to believe that the entire engagement had not yet lasted ten minutes. As Wheeler cautiously surveyed the inferno to the south, he noticed that the hemisphere seemed to have lost some of its symmetry. At first he thought that one of the generators might have failed, so that the protective field could no longer be maintained. Then he saw that the lake of lava was at least a kilometre across, and he guessed that the whole fort had floated off its foundations. Probably the defenders were not even aware of the fact. Their insulation must be taking care of solar heats, and would hardly notice the modest warmth of molten rock.

  And now a strange thing was beginning to happen. The rays with which the battle was being fought were no longer quite invisible, for the fortress was no longer in a vacuum. Around it the boiling rock was releasing enormous volumes of gas, through which the paths of the rays were as clearly visible as searchlights in a misty nig
ht on Earth. At the same time Wheeler began to notice a continual hail of tiny particles around him. For a moment he was puzzled; then he realized that the rock vapour was condensing after it had been blasted up into the sky. It seemed too light to be dangerous, and he did not mention it to Jamieson—it would only give him something else to worry about. As long as the dust fall was not too heavy, the normal insulation of the suits could deal with it. In any case, it would probably be quite cold by the time it got back to the surface.

  The tenuous and temporary atmosphere round the dome was producing another unexpected effect. Occasional flashes of lightning darted between ground and sky, draining off the enormous static charges that must be accumulating around the fort. Some of those flashes would have been spectacular by themselves—but they were scarcely visible against the incandescent clouds that generated them.

  Accustomed though he was to the eternal silences of the Moon, Wheeler still felt a sense of unreality at the sight of these tremendous forces striving together without the least whisper of sound. Sometimes a gentle vibration would reach him, perhaps the rock-borne concussion of falling lava. But much of the time, he had the feeling that he was watching a television program when the sound had failed.

  Afterward, he could hardly believe he had been such a fool as to expose himself to the risks he was running now. At the moment, he felt no fear—only an immense curiosity and excitement. He had been caught, though he did not know it, by the deadly glamour of war. There is a fatal strain in men that, whatever reason may say, makes their hearts beat faster when they watch the colours flying and hear the ancient music of the drums.

  Curiously enough, Wheeler did not feel any sense of identification with either side. It seemed to him, in his present abnormally overwrought mood, that all this was a vast, impersonal display arranged for his special benefit. He felt something approaching contempt for Jamieson, who was missing everything by seeking safety.

  Perhaps the real truth of the matter was that having just escaped from one peril, Wheeler was in the exalted state, akin to drunkenness, in which the idea of personal danger seems absurd. He had managed to get out of the dust bowl—nothing else could harm him now.