To fuel this increased luminosity, immense convection cycles had started — cells which spanned millions of miles, and which would persist for hundreds of days. The convection cycles dug deep into the mantle to haul energy out of the core regions to be pumped out to space — and along with the energy dredging, Lieserl saw, the convection was changing the composition of the Sun, polluting the outer regions with nucleosynthesis products like nitrogen-14, dug out of the core regions.

Coherent maser radiation flashed along the flanks of the convection cells, startling her with its intensity.

As she traveled through the thin gas she felt a faint buffeting, a rocking of the exotic-matter framework of her Interface.

There was turbulence here. The convection process wasn’t perfectly efficient, and energy, struggling to escape from the inner regions, was forced to dissipate itself in a complex, space-filling array of turbulent cells. The Sun’s magnetic field was affected by this turbulence. She saw how the flux was pushed out of the interior of the cells, to form fine sheets across the cells’ surfaces — but the sheets were unstable, and they burst like sheets of soap film, leaving ropes of flux at the intersections of the turbulence cells. Lieserl swam through a million-mile mesh of the magnetic flux ropes.

It was bizarre to think that — if she wished — she could travel out as far as the old orbital radius of Earth, without ever leaving the substance of the Sun.

Lieserl knew — with remote, abstract sadness — that the inner planets, out as far as Earth, must have been consumed in the Sun’s cooling, red-tinged mantle. She remembered her brief, golden childhood: the sparkling beaches of the Aegean, the sharp, enticing scent of the sea, the feel of sand between her babyish toes. Perhaps humans, somewhere, were still enjoying such experiences.

But Earth, the only world she had known, was gone forever.

“Arrow Maker, tell me what you see. Can you see the stars?”

Arrow Maker looked down, through the pod hull. “I don’t understand.”

Uvarov’s voice, disembodied, became ragged; Arrow Maker imagined the old man thrashing feebly beneath his blanket. “Can you see Sol? You should be able to, by now. Arrow Maker — is Earth there? Is — ”

“No.”

“Maker — ”

“No.”

Arrow Maker shouted the last word, and Uvarov subsided.

The illuminated lip of the port had passed right over the pod now; it was visible to Maker as a frame of light above his head. The outer darkness had enclosed the pod… No, he was thinking about this in the wrong way. The darkness was the Universe; as if in some obscene, mechanical birth, the pod had been expelled from the lifedome into the dark.

The base of the lifedome hung over him like a huge belly of glass and metal, receding slowly, its curvature becoming apparent. And through it — distorted, rendered misty by the base material — he made out the light-filled interior of the dome. He could see bits of detail: elevator shafts from the decks above, control consoles like the one at which he’d left Spinner, Morrow and Uvarov — why, if he had eyes sharp enough, he could probably look up now and see the soles of his daughter’s feet.

Suddenly the reality of it hit him. He had traveled outside the lifedome. He was beyond its protective hull — perhaps the first human to have ventured outside in half a millennium — and now he was suspended in the emptiness which made up most of the forbidding, lifeless Universe.

“Arrow Maker. Talk to us.”

Arrow Maker laughed, his voice shrill in his own ears. “I’m suspended in a glass bubble, surrounded by emptiness. I can see the lifedome. It’s like — ”

“Like what?” Morrow’s voice, sounding intrigued.

“Like a box of light. Quite — beautiful. But very fragile-looking…”

Uvarov cut in, “Oh, give me strength. What else, Arrow Maker?”

Arrow Maker twisted his head, to left and right.

To the right of the pod, an immense pillar of sculpted metal swept through space. It was huge, quite dwarfing the pod, like the trunk of some bizarre artificial tree. It merged seamlessly with the lifedome, and it was encrusted with cups, ribs and flowers of shaped metal.

Maker described this.

“The spine,” Uvarov said impatiently. “You’re traveling parallel to the spine of the GUTship. Yes, yes; just as I told you. Arrow Maker, can you see the Interface? The wormhole — ”

Arrow Maker leaned forward and peered down, past the seats and stanchions, through the pod’s base. This spine descended for a great distance, its encrustation of parasitic forms dwindling with perspective, until the spine narrowed to a mere irregular line. The whole form was no less than three miles long, Uvarov had told him.

Beyond the spine’s end was a sheet of light which hid half the sky. The light was eggshell-blue and softly textured; it was like a vast, inverted flower petal, ribbed with lines of stronger, paler hue. As Arrow Maker watched he could see a slow evolution in the patterns of light, with the paler lines waving softly, coalescing and splitting, like hair in a breeze. The light cast blue highlights, rich and varying, from the structures along the spine.

He was looking at the GUTdrive: the light came from the primeval energies, Uvarov had told him, which had hurled the ship and all its cargo through space and time for a thousand years.

Silhouetted against the sheet of creation light, just below the base of the spine, was a dark, irregular mass, too distant for Arrow Maker to resolve: that was the tethered ice asteroid, which still — after all these years — patiently gave up its flesh to serve as reaction mass for the great craft. And -

“Uvarov. The Interface. I see it.”

There, halfway down the spine’s gleaming length, was a tetrahedral structure: edged in glowing blue, tethered to the spine by what looked like hoops of gold.

“Good.” He heard a tremulous relief in Uvarov’s voice. “Good. Now, Arrow Maker — look around the sky, and describe the stars you see.”

Arrow Maker stared, beyond the ship. The spine, the Interface, were suspended in darkness.

Uvarov’s speech became rushed, almost slurred. “Why, we might be able to place our position — and the date — by the constellations. If I can find the old catalogs; those damn survivalists in the Decks must have retained them. And — ”

“Uvarov.” Arrow Maker tried to inject strength into his voice. “Listen to me. There’s something wrong.”

“There can’t be. I — ”

“There are no constellations. There are no stars.” Beyond the ship there was only emptiness; it was as if the great ship, with its flaring drive and teeming lifedome, was the only object in the Universe…

No, that wasn’t quite true. He stared to left and right, scanning the equator of the gray-black sky around him; there seemed to be something there — a ribbon of light, too faint to make out color.

He described this to Uvarov.

“The starbow.” Uvarov’s voice sounded much weaker, now. “But that’s impossible. If there’s a starbow we must be traveling, still, at relativistic velocities. But we can’t be.” The old, dead voice cracked. “Maker, you’ve seen the stars yourself.”

“No.” Arrow Maker tried to make his voice gentle. “Uvarov, all I’ve ever seen were points of light in a sky-dome… Maybe they weren’t stars at all.”

If, he thought ruefully, the stars ever existed at all.

He stared at the mass of the spine as it slid upwards past him, suddenly relishing its immensity, its detail. He was glad there were no stars. If this ship was all that existed, anywhere in the Universe, then it would be enough for him. He could spend a lifetime exploring the worlds contained within its lifedome, and there would always be the forest to return to. And -