3001 The Final Odyssey

chapter 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 kilometres 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 armour 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 kilometres 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 metres 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 kilometres 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 sulphur 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.