He continued to talk, trying to sound as if he was completely sincere, instead of skirting the edge of truth.

  “This is Frank Poole aboard the shuttle Falcon, descending towards Europa. I assume that some outside force has taken charge of my spacecraft, and will be landing it safely.”

  “Dave – this is your old shipmate Frank. Are you the entity that is controlling me? I have reason to think that you are on Europa.

  “If so – I look forward to meeting you – wherever or whatever you are.”

  Not for a moment did he imagine there would be any reply: even Ganymede Control appeared to be shocked into silence.

  And yet, in a way, he had an answer. Falcon was still being permitted to descend towards the Sea of Galilee.

  Europa was only fifty kilometers below; with his naked eyes Poole could now see the narrow black bar where the greatest of the Monoliths stood guard – if indeed it was doing that – on the outskirts of Tsienville.

  No human being had been allowed to come so close for a thousand years.

  25. Fire in the Deep

  For millions of years it had been an ocean world, its hidden waters protected from the vacuum of space by a crust of ice. In most places the ice was kilometers thick, but there were lines of weakness where it had cracked open and torn apart. Then there had been a brief battle between two implacably hostile elements that came into direct contact on no other world in the Solar System, The war between Sea and Space always ended in the same stalemate; the exposed water simultaneously boiled and froze, repairing the armor of ice.

  The seas of Europa would have frozen completely solid long ago without the influence of nearby Jupiter. Its gravity continually kneaded the core of the little world; the forces that convulsed Io were also working there, though with much less ferocity. Everywhere in the deep was evidence of that tug-of-war between planet and satellite, in the continual roar and thunder of submarine earthquakes, the shriek of gases escaping from the interior, the infrasonic pressure waves of avalanches sweeping over the abyssal plains. By comparison with the tumultuous ocean that covered Europa, even the noisy seas of Earth were muted.

  Here and there, scattered over the deserts of the deep, were oases that would have amazed and delighted any terrestrial biologist. They extended for several kilometers around tangled masses of pipes and chimneys deposited by mineral brines gushing from the interior. Often they created natural parodies of Gothic castles, from which black, scalding liquids pulsed in a slow rhythm, as if driven by the beating of some mighty heart. And like blood, they were the authentic sign of life itself.

  The boiling fluids drove back the deadly cold leaking down from above, and formed islands of warmth on the sea-bed. Equally important, they brought from Europa's interior all the chemicals of life. Such fertile oases, offering food and energy in abundance, had been discovered by the twentieth-century explorers of Earth's oceans. Here they were present on an immensely larger scale, and in far greater variety.

  Delicate, spidery structures that seemed to be the analogue of plants flourished in the “tropical” zones closest to the sources of heat. Crawling among these were bizarre slugs and worms, some feeding on the plants, others obtaining their food directly from the mineral-laden waters around them. At greater distances from the submarine fires around which all these creatures warmed themselves lived sturdier, more robust organisms, not unlike crabs or spiders.

  Armies of biologists could have spent lifetimes studying one small oasis. Unlike the Palaeozoic terrestrial seas, the Europan abyss was not a stable environment, so evolution had progressed with astonishing speed, producing multitudes of fantastic forms. And all were under the same indefinite stay of execution; sooner or later, each fountain of life would weaken and die, as the forces that powered it moved their focus elsewhere. All across the Europan sea-bed was evidence of such tragedies; countless circular areas were littered with the skeletons and mineral-encrusted remains of dead creatures, where entire chapters of evolution had been deleted from the book of life. Some had left as their only memorial huge, empty shells like convoluted trumpets, larger than a man. And there were clams of many shapes – bivalves, and even trivalves, as well as spiral stone patterns, many meters across – exactly like the beautiful ammonites that disappeared so mysteriously from Earth's oceans at the end of the Cretaceous Period.

  Among the greatest wonders of the Europan abyss were rivers of incandescent lava, pouring from the calderas of submarine volcanoes. The pressure at these depths was so great that the water in contact with the red-hot magma could not flash into steam, so the two liquids co-existed in an uneasy truce.

  There, on another world and with alien actors, something like the story of Egypt had been played out long before the coming of Man. As the Nile had brought life to a narrow ribbon of desert, so this river of warmth had vivified the Europan deep. Along its banks, in a band never more than a few kilometers wide, species after species had evolved and flourished and passed away. And some had left permanent monuments.

  Often, they were not easy to distinguish from the natural formations around the thermal vents, and even when they were clearly not due to pure chemistry, one would be hard put to decide whether they were the product of instinct or intelligence. On Earth, the termites reared condominiums almost as impressive as any found in the single vast ocean that enveloped this frozen world.

  Along the narrow band of fertility in the deserts of the deep, whole cultures and even civilizations might have risen and fallen, armies might have marched – or swum – under the command of Europan Tamberlanes or Napoleons. And the rest of their world would never have known, for all their oases were as isolated from one another as the planets themselves, The creatures who basked in the glow of the lava rivers, and fed around the hot vents, could not cross the hostile wilderness between their lonely islands. If they had ever produced historians and philosophers, each culture would have been convinced that it was alone in the Universe.

  Yet even the space between the oases was not altogether empty of life; there were hardier creatures who had dared its rigours. Some were the Europan analogues of fish – streamlined torpedoes, propelled by vertical tails, steered by fins along their bodies. The resemblance to the most successful dwellers in Earth's oceans was inevitable; given the same engineering problems, evolution must produce very similar answers. Witness the dolphin and the shark – superficially almost identical, yet from far distant branches of the tree of life.

  There was, however, one very obvious difference between the fish of the Europan seas and those in terrestrial oceans; they had no gills, for there was hardly a trace of oxygen to be extracted from the waters in which they swam. Like the creatures around Earth's own geothermal vents, their metabolism was based on sulfur compounds, present in abundance in this volcanic environment.

  And very few had eyes. Apart from the flickering glow of lava outpourings, and occasional bursts of bioluminescence from creatures seeking mates, or hunters questing prey, it was a lightless world.

  It was also a doomed one. Not only were its energy sources sporadic and constantly shifting, but the tidal forces that drove them were steadily weakening. Even if they developed true intelligence, the Europans were trapped between fire and ice.

  Barring a miracle, they would perish with the final freezing of their little world.

  Lucifer had wrought that miracle.

  26. Tsienville

  In the final moments, as he came in over the coast at a sedate hundred kilometers an hour, Poole wondered if there might be some last-minute intervention. But nothing untoward happened, even when he moved slowly along the black, forbidding face of the Great Wall.

  It was the inevitable name for the Europa Monolith as, unlike its little brothers on Earth and Moon, it was lying horizontally, and was more than twenty kilometers long. Although it was literally billions of times greater in volume than TMA ZERO and TMA ONE, its proportions were exactly the same – that intriguing ratio 1:4:9, inspirer of so much numerolo
gical nonsense over the centuries.

  As the vertical face was almost ten kilometers high, one plausible theory maintained that among its other functions the Great Wall served as a wind-break, protecting Tsienville from the ferocious gales that occasionally roared in from the Sea of Galilee. They were much less frequent now that the climate had stabilized, but a thousand years earlier they would have been a severe discouragement to any life-forms emerging from the ocean.

  Though he had fully intended to do so, Poole had never found time to visit the Tycho Monolith – still Top Secret when he had left for Jupiter – and Earth's gravity made its twin at Olduvai inaccessible to him. But he had seen their images so often that they were much more familiar than the proverbial back of the hand (and how many people, he had often wondered, would recognize the backs of their hands?). Apart from the enormous difference in scale, there was absolutely no way of distinguishing the Great Wall from TMA ONE and TMA ZERO – or, for that matter, the “Big Brother” Monolith that Discovery and the Leonov had encountered orbiting Jupiter.

  According to some theories, perhaps crazy enough to be true, there was only one archetypal Monolith, and all the others – whatever their size – were merely projections or images of it. Poole recalled these ideas when he noticed the spotless, unsullied smoothness of the Great Wall's towering ebon face. Surely, after so many centuries in such a hostile environment, it should have collected a few patches of grime! Yet it looked as immaculate as if an army of window-cleaners had just polished every square centimeter.

  Then he recalled that although everyone who had ever come to view TMA ONE and TMA ZERO felt an irresistible urge to touch their apparently pristine surfaces, no one had ever succeeded. Fingers – diamond drills – laser knives – all skittered across the Monoliths as if they were coated by an impenetrable film. Or as if – and this was another popular theory – they were not quite in this universe, but somehow separated from it by an utterly impassable fraction of a millimeter.

  He made one complete, leisurely circuit of the Great Wall, which remained totally indifferent to his progress. Then he brought the shuttle – still on manual, in case Ganymede Control made any further attempts to “rescue” him – to the outer limits of Tsienville, and hovered there looking for the best place to land.

  The scene through Falcon's small panoramic window was wholly familiar to him; he had examined it so often in Ganymede recordings, never imagining that one day he would be observing it in reality. The Europs, it seemed, had no idea of town planning; hundreds of hemispherical structures were scattered apparently at random over an area about a kilometer across. Some were so small that even human children would feel cramped in them; though others were big enough to hold a large family, none was more than five meters high.

  And they were all made from the same material, which gleamed a ghostly white in the double daylight. On Earth, the Esquimaux had found the identical answer to the challenge of their own frigid, materials-poor environment; Tsienville's igloos were also made of ice.

  In lieu of streets, there were canals – as best suited creatures who were still amphibious, and apparently returned to the water to sleep. Also, it was believed, to feed and to mate, though neither hypothesis had been proved.

  Tsienville had been called “Venice, made of ice”, and Poole had to agree that it was an apt description. However, there were no Venetians in sight; the place looked as if it had been deserted for years.

  And here was another mystery; despite the fact that Lucifer was fifty times brighter than the distant Sun, and was a permanent fixture in the sky, the Europs still seemed locked to an ancient rhythm of night and day. They returned to the ocean at sunset, and emerged with the rising of the Sun – despite the fact that the level of illumination had changed by only a few per cent. Perhaps there was a parallel on Earth, where the life cycles of many creatures were controlled as much by the feeble Moon as the far more brilliant Sun.

  It would be sunrise in another hour, and then the inhabitants of Tsienville would return to land and go about their leisurely affairs – as by human standards, they certainly were. The sulfur-based biochemistry that powered the Europs was not as efficient as the oxygen-driven one that energized the vast majority of terrestrial animals. Even a sloth could outrun a Europ, so it was difficult to regard them as potentially dangerous. That was the Good News; the Bad News was that even with the best intentions on both sides, attempts at communication would be extremely slow – perhaps intolerably tedious.

  It was about time, Poole decided, that he reported back to Ganymede Control. They must be getting very anxious, and he wondered how his co-conspirator, Captain Chandler, was dealing with the situation.

  “Falcon calling Ganymede. As you can doubtless see, I have – er – been brought to rest just above Tsienville. There is no sign of hostility, and as it's still solar night here all the Europs are underwater. Will call you again as soon as I'm on the ground.”

  Dim would have been proud of him, Poole thought, as he brought Falcon down gently as a snowflake on a smooth patch of ice. He was taking no chances with its stability, and set the inertial drive to cancel all but a fraction of the shuttle's weight – just enough, he hoped, to prevent it being blown away by any wind.

  He was on Europa – the first human in a thousand years. Had Armstrong and Aldrin felt this sense of elation, when Eagle touched down on the Moon? Probably they were too busy checking their Lunar Module's primitive and totally unintelligent systems.

  Falcon, of course, was doing all this automatically. The little cabin was now very quiet, apart from the inevitable – and reassuring – murmur of well-tempered electronics. It gave Poole a considerable shock when Chandler's voice, obviously pre-recorded, interrupted his thoughts.

  “So you made it! Congratulations! As you know, we're scheduled to return to the Belt week after next, but that should give you plenty of time.”

  “After five days, Falcon knows what to do. She'll find her way home, with or without you. So good luck!”

  MISS PRINGLE

  ACTIVATE CRYPTO PROGRAM

  STORE

  Hello, Dim – thanks for that cheerful message! I feel rather silly using this program – as if I'm a secret agent in one of the spy melodramas that used to be so popular before I was born. Still, it will allow some privacy, which may be useful. Hope Miss Pringle has downloaded it properly... of course, Miss P, I'm only joking!

  By the way, I'm getting a barrage of requests from all the news media in the Solar System. Please try to hold them off – or divert them to Dr Ted. He'll enjoy handling them...

  Since Ganymede has me on camera all the time, I won't waste breath telling you what I'm seeing. If all goes well, we should have some action in a few minutes – and we'll know if it really was a good idea to let the Europs find me already sitting here peacefully, waiting to greet them when they come to the surface...

  Whatever happens, it won't be as big a surprise to me as it was to Dr Chang and his colleagues, when they landed here a thousand years ago! I played his famous last message again, just before leaving Ganymede. I must confess it gave me an eerie feeling – couldn't help wondering if something like that could possibly happen again... wouldn't like to immortalize myself the way poor Chang did...

  Of course, I can always lift off if something starts going wrong... and here's an interesting thought that's just occurred to me... I wonder if the Europs have any history – any kind of records... any memory of what happened just a few kilometers from here, a thousand years ago?

  27. Ice and Vacuum

  “...This is Dr Chang, calling from Europa. I hope you can hear me, especially Dr Floyd – I know you're aboard Leonov... I may not have much time... aiming my suit antenna where I think you are... please relay this information to Earth.

  “Tsien was destroyed three hours ago. I'm the only survivor. Using my suit radio – no idea if it has enough range, but it's the only chance. Please listen carefully...

  “THERE IS LIFE ON EUROPA.
I repeat: THERE IS LIFE ON EUROPA...

  “We landed safely, checked all the systems, and ran out the hoses so we could start pumping water into our propellant tanks immediately... just in case we had to leave in a hurry.

  “Everything was going according to plan... it seemed almost too good to be true. The tanks were half full when Dr Lee and I went out to check the pipe insulation. Tsien stands – stood – about thirty meters from the edge of the Grand Canal. Pipes went directly from it and down through the ice. Very thin – not safe to walk on.

  “Jupiter was quarter full, and we had five kilowatts of lighting strung up on the ship. She looked like a Christmas tree – beautiful, reflected on the ice...

  “Lee saw it first – a huge dark mass rising up from the depths. At first we thought it was a school of fish – too large for a single organism – then it started to break through the ice, and began moving towards us.

  “It looked rather like huge strands of wet seaweed, crawling along the ground. Lee ran back to the ship to get a camera – I stayed to watch, reporting over the radio. The thing moved so slowly I could easily outrun it. I was much more excited than alarmed. Thought I knew what kind of creature it was – I've seen pictures of the kelp forests off California – but I was quite wrong.

  “...I could tell it was in trouble. It couldn't possibly survive at a temperature a hundred and fifty below its normal environment. It was freezing solid as it moved forward – bits were breaking off like glass – but it was still advancing towards the ship, a black tidal wave, slowing down all the time.

  “I was still so surprised that I couldn't think straight and I couldn't imagine what it was trying to do. Even though it was heading towards Tsien it still seemed completely harmless, like – well, a small forest on the move. I remember smiling – it reminded me of Macbeth's Birnam Wood...