Michael Poole’s invisible ghost-touch evaporated. Spinner-of-Rope lifted her hands from the waldoes.

Her job was done, then. She pulled her fingers inside the body of her gloves and balled her stiff hands into fists, digging her nails into the palms of her hands. She felt herself shudder, from fear and exhaustion. There was a stabbing in the small of her back, and across her shoulder blades, just below her neck; she twisted in her couch and flexed her spine, trying to work out the stiffness.

Then she looked out, beyond the construction-material cage, for the first time.

“Dr. Uvarov. Dr. Garry Uvarov.”

The voice, flat and mechanical, roused him from a broken sleep.

He opened his mouth to reply, and ropy saliva looped across his lips. “What is it now?”

“Is there anything you require?” The voice, generated by the pod’s limited processors, didn’t even bear a semblance of humanity, and it came — maddeningly! — from all around him.

“Yes,” he said. He felt himself shivering, distantly; he felt cold. Was the power in here failing already?

How long had it been, since his abrupt abandonment by Lieserl and Mark Wu?

“Yes,” he told the pod again. “Yes, there is something I require. Take me back to the Northern.”

The pod paused, for long seconds.

Uvarov felt the cold settle over his bones. Was this how he was to die, suspended in the thoughts of an idiot mechanical? Was he to suffer a final betrayal at the hands of technology, just as the AS nanobots had been slowly killing him for years?

Well, if he was to die, he would take with him one deep and intense regret: that he had not lived to see the conclusion of his grand design, his experiment at extending the natural longevity of his race. He knew how others had seen him: as obsessed with his eugenics objectives, as a monomaniac perhaps. But — ah! What an achievement it would have been! What a monument…

Ambition burned within him still, intense, almost all consuming, betrayed by the failure of his body.

His thoughts softened, and he felt himself grow more diffuse, his awareness drifting off into the warm, comfortable caverns of his memory.

The pod spoke again. “I’m unable to comply with your request, Doctor. I can’t obtain a fix on the Northern. I’m sorry. Would you like me to — ”

“Then kill me.” He twisted his head from side to side, relishing the stabs of pain in his neck. “I’m stranded here. I’m going to die, as soon as my supplies run out. Kill me now. Turn off the damn power.”

“I can’t comply with that, either, Dr. Uvarov.”

But Uvarov was no longer listening. Once more he felt himself falling into a troubled — perhaps final — sleep, and his ruined lips moved slowly.

“Kill me, you damn mechanical…”

The torus of ragged, fragmented string loops was gone. Now, cosmic string crossed the cavity: great, wild, triumphant whorls of it, shining a false electric blue in the sky dome’s imager.

This one, tremendous, complex, multiple loop of string filled the cavity at the bottom of the gravity well. This was — astonishingly, unbearably — a single object, an artifact, at least ten million light-years across.

Louise Ye Armonk — with Mark, Lieserl and Morrow — hovered on zero-gee scooters, suspended beneath the crown of the skydome. Beneath Louise — she was distantly aware — the layers of forest were filled with the rich, comforting noises: the calls of birds and monkeys and the soft burps of frogs, sounds of busy life which persisted even here at the end of time…

Beyond the clear dome, string filled the Universe.

Here, a hundred thousand years into the past, the galaxies still fell, fragmenting and blue-shifted, into the deepest gravity well in the Universe. And the Northern had emerged from its jaunts through the string loop’s spacetime defects to find itself once more inside a star-walled cavity, at the bottom of this Universal well.

There the similarity ended, though, Louise thought. The cavity walls were much smoother than in the future, containing rather fewer of the ragged holes she’d noted… The walls looked almost artificially smooth here, she thought uneasily.

And, of course, there was the Ring, whole and magnificent.

The Ring was a hoop woven from a billion-light-year length of cosmic string. The Northern was positioned somewhere above the plane of the Ring. The near side of the artifact formed a tangled, impenetrable fence over the lifedome, twisted exuberantly into arcs and cusps, with shards of galaxy images glittering through the morass of spacetime defects. And the far side of the object was visible as a pale, hard band, remote across the blue-shifted sky.

The rough disc of space enclosed by the Ring — a disc no less than ten million light-years across, Louise reminded herself — seemed virtually empty. Perhaps, she mused, in this era the Xeelee were actively working to keep that central region clear.

…Clear, Louise saw as she looked more carefully, save for a single, glowing point of light, right at the geometric center of the Ring. She saw how Lieserl was staring into that point of light, her mouth half-open.

Spinner-of-Rope’s precipitate action had delivered them, back through time, to another snapshot-timeslice of this war in Heaven… and this was, it seemed, an era not far removed from the Ring’s final fall.

She was aware of their eyes — Mark’s, Lieserl’s, Morrow’s resting on her, expectantly. On her.

Remember what Lieserl said, she told herself. I’m a survival mechanism. That’s all. I have to keep functioning, for just a little while longer… She reached deep inside her.

She clapped her hands. “All right, people — Mark, Lieserl. Let’s do some work. I think it’s obvious we’ve delivered ourselves right into the middle of a war zone. We know that, at this moment, the photino birds must be hitting this Ring from all sides — because, within a hundred thousand years, we know that the Ring is going to be destroyed. That gives me the feeling that we don’t have much time, before one side or other notices we’re here…”

“I think you’re right, Louise,” Mark said. Both the Virtuals, on high-capacity data links to the central processors, were working on different aspects of the situation. “I don’t think we should be fooled by the fact that most of the action in this incredible war seems to be occurring at sublight velocities, so that — on this scale it has all the pace of an ant column crossing the Sahara. Let’s not forget the Xeelee have a hyperdrive — which we’ve stolen — and, for all we know, so do the photino birds. We could be discovered at any time.”

“So give me a summary of the environment.”

Mark nodded. “First of all, our position in time: Spinner-of-Rope constructed enough closed timelike paths for us to have traveled a hundred thousand years into the past, back from the era to which our first journey brought us.” He raised his face to the skydome and rose into the air by a few feet, absently forgetting to take his Virtual-scooter with him. “The Ring is complete in this era, as far as we can tell. Its mass is immense — in fact we’re suffering inertial drag from it. Kind of a lot of drag, in fact… We’re being hauled around, through space, by the Ring. Spinner-of-Rope seems to be compensating…”

“Lieserl. Tell me what you have.”

Lieserl seemed to have to tear her eyes away from that tantalizing point of light at the heart of the Ring. She looked down at Louise.

“I have the Ring, Louise. We have been restored to an era before its destruction. Bolder’s Ring is a single loop of cosmic string… but an immense one, no less than ten million light-years across and with the mass of tens of thousands of galaxies, united into one seamless whole. The string is twisted over on itself like wool wrapped around a skein; the Ring’s topography is made up of string arcs moving at close to lightspeed, and cusps which actually reach light speed. The motion is complex, but — as far as I can tell it’s non-intersecting. The Ring could persist forever.