This is just the beginning, Malenfant whispered.

Sheena 5:

Drifting between worlds, the spacecraft was itself a miniature

planet, a bubble of ocean just yards across.

The water was sufficient to protect its occupants from cosmic and solar radiation. And the water sustained concentric shells of life: a mist of diatoms feeding off the raw sunlight, and within them, in the deeper blue water, a shell of krill and crustaceans and small fish schools, hunting and browsing.

And, at the center of it all, a single enhanced cephalopod.

Here was Sheena, swimming through space.

Space. Yes, she understood what that meant, that she was no longer in the wide oceans of Earth but in a small, self-contained ocean of her own that drifted through emptiness, a folded-over ocean she shared only with the darting fish and the smaller, mindless animals and plants on which they browsed.

She glided at the heart of the Nautilus, where the water that passed through her mantle, over her gills, was warmest, richest. The core machinery, the assemblage of devices that maintained life here, was a black mass before her, suspended in dark water, lights winking over its surface, weeds and grasses clinging to it. Sheena saw no colors; she swam through a world of black, white, and gray. But she could discern polarized light; and so now she saw that the light that gleamed from the polished surfaces of the machinery was subtly twisted, this way and that, giving her a sense of the solidity and extent of the machinery.

When the ship’s roll took her into shadow, she hunted and browsed.

She would rest on the sand patches that had been stuck to the metal, changing her mantle color so as to be almost invisible. When the fish or the krill came by, all unawares, she would dart out and snatch them, crushing them instantly in her hard beak, ignoring their tiny cries.

Such simple ambushes were sufficient to feed her, so confused did the fish and krill appear in this new world that lacked up and down and gravity. But sometimes she would hunt more ambitiously, luring and stalking and pursuing, as if she were still among the rich Caribbean reefs.

But all too soon the ship’s languid roll brought her into the light, and brief night gave way to false day.

Rippling her fins, she swam away from the machinery cluster, away from the heart of the ship, where she lived with her shoals offish. As she rose the water flowing through her mantle cooled, the rich oxygen thinning. She was swimming out through layers of life, and she sensed the subtle sounds of living things washing through the sphere: the smooth rush of the fish as they swam in their tight schools, the bubbling murmur of the krill on which they browsed, the hiss of the diatoms and algae that fed them, and the deep infrasonic rumble of the water itself, compression waves pulsing through its bulk.

And just as each successive sphere of water was larger than the one it contained, so Sheena knew there was a hierarchy of life. To sustain her, there had to be ten times her weight in krill, and a hundred times in diatoms.

And if there had been other squid, of course, those numbers would increase. But there was no other squid here but herself.

For now.

She could see, through misty, life-laden water, the ship’s hull, a membrane above her like an ocean surface. Except that it wasn ‘t above her, as it would be in a true ocean. And there was no sandy ocean floor below. Instead the membrane was all around her, closed on itself, shimmering in great slow waves that curled around the sphere’s belly.

This was self-evidently a complex world, a curved world, a world without the simple top and bottom of the ocean; and the light was correspondingly complex, its polarization planes random, or else spiraling down around her.

But Sheena hunted in three dimensions. She could come to terms with all this strangeness. She knew she must, in fact.

She reached the wall of the ship.

The membrane was a firm, if flexible, wall. If she pushed at it, it pushed back.

Human eyes could see that the wall was tinted gold. Dan had told her how beautiful this great golden egg had been in the skies of Earth, as it receded to the stars. Sheena ship good pretty, he said. Like Earth. Ship people see, gold bubble, ship of water.

Grass algae grew on the wall, their long filaments dangling and wafting in the currents. Crabs and shellfish grazed on the grass algae. The benthic grazers helped feed her, and in the process kept the walls clean.

Every creature in this small ocean had a part to play. Here, for instance, she drifted past a floating bank of seaweed. The seaweed cleaned the water and used up drifting food that the algae and diatoms could not consume. And the seaweed was useful in itself. One of Sheena’s jobs was to gather the weed, when it grew too thick, and deliver it to a hopper in the machinery cluster. There it could be spun into fibers that Dan called sea silk. The sea silk would be used when she got to her destination, to make and repair the equipment she would use there.

Now the ship’s slow rotation carried Sheena into the light of a milky, blurred disc. It was the sun — dimmed by the membrane so it did not hurt her eyes — with, near it, a smaller crescent. That, she knew, was the Earth, all its great oceans reduced to a droplet. The craft scooted around the sun after Earth like a fish swimming after its school, seeking the rock that was the target for this mission.

Once, swimming under the arching membrane like this, she had been startled by a starburst of light, only a few moments’ swim from her. It had disappeared as soon as it had occurred, but it had seemed to her that there was a flaw in the membrane — a small patch that had lost its lustrous glow. She had been able to see from the muddled polarization how the composition of the water had been disturbed beneath the flaw.

Then she had seen something moving, outside the membrane. She cowered, flashing signals of false threat and concealment, thinking it was some deep-space predator.

It was no predator. It was just a box that squirted back and forth, emitting gentle little farts of glittering crystals. It was pulling a patch over the hole.

Dan told her it was a firefly robot, a smart little box with its own power supply and fuel and miniaturized machinery and cameras and machine intelligence. The ship carried a shoal of these small craft for external inspection and repairs like this.

But the little craft’s life was limited, intended for a single use only, and it could achieve only one thing, which was to fix the membrane — unlike Sheena, who could do many different things. When its job was done, its fuel expended, the craft neatly folded away its tool-bearing arms and used the last breath of its fuel to push itself away from the ship. Sheena had watched as the little craft, discarded, dwindled to a sunlit point.

She had learned that her ship leaked all the time anyway, from tiny flaws and miniature punctures. And every few days the throwaway robots would scuttle over the membrane, tracking the vapor clouds, fixing the worst of the leaks before sacrificing themselves.

She let the lazy, whale-like roll of the ship carry her away from the glare of the sun, and she peered into the darkness, where she could see the stars.