Electric-blue light flared, and asteroid dirt was hurled up before them. Cohl twisted and fired into the blue-tinged fog of dust. She glimpsed Xeelee drones, pressing down on her trench. There was something above her; she felt it before she saw it. She rolled on her back, preparing to fire again.

But the ship was a flitter, small, unarmored. Its door was open and a ladder hung down.

“Cohl!” She recognized the voice; it was Enduring Hope. “Evac!”

“No. The cannon—”

“The Xeelee shot the heart out of it. The Rock is finished. There’s no point dying here.”

“I have to stay.” Of course she did; that was Doctrinal. You weren’t supposed to keep yourself alive, not while there were still enemy to shoot at. “A brief life burns brightly,” she said reflexively.

“Balls,” Hope said with feeling. “Come on, Cohl; I’ve risked my ass to come flying around this Rock looking for you.”

She made a quick decision. Reluctantly she turned to Blayle. “Sergeant…”

He didn’t respond. There was a small scar on Blayle’s faceplate, a puncture almost too small to see. A thousand years of history ends here, she thought. She wished she could close his eyes.

In the end only two of Cohl’s platoon were lifted out with her, two out of the nine she had led out of the trench.

As the flitter lifted, she saw the landscape of the Rock open up. Its whole surface crawled with light as Xeelee drones and human fighters hurled energy at each other, all in utter silence. It was an extraordinary sight. But already the nightfighters were closing in to end this millennial drama for good.

The flitter squirted away. Cohl, still locked in her skinsuit, closed her eyes and tried to control her trembling.

Pirius tried not to watch the chronometer. And he tried not to think about his own fatigue.

He felt as if he had been walking a high-wire for six hours. He tried to concentrate on the moment, to get through the next jump, and the next, and the next. If you didn’t survive the present, after all, future and past didn’t matter; that old earthworm Hama Druz had been right about that much. For all their training and sims, however, they hadn’t realized how exhausting this was going to be, this tightrope walk through the center of the Galaxy. He hoped he would have the physical and mental strength to actually fight at the end of it.

He shut the passage of time out of his mind. So he was surprised when a gentle chime sounded on the comm loops, but he understood its significance immediately.

Ahead, the grav shield was dissolving, and in the sky around him the stars and gas masses of this shining, complex place were swimming back to where they should be.

“No sign of our escort,” Bilson said.

“We got through,” Pirius murmured.

“Yes, sir.” Even Jees’s steady voice betrayed an edge of fatigue now. She should have been spelled by Darc, and Pirius knew that for the last hour she had been nursing one failing system after another.

Still, she had delivered them here, just as the operational plan had dictated, and with no more losses: seven ships had survived, out of ten that had started.

Somebody called, “What’s that?”

It was a star, a hot, bright, blue star, a young one — not part of the IRS 16 cluster, though; they were far from that now. And there seemed to be a cloud around it, a flattened disc, like the shields of rock from which planets formed.

“That,” said Bilson, “is SO-2. We’re exactly where we are supposed to be, sir.”

Engineer Cabel was less clued in. “And SO-2 is—”

“The innermost star in orbit.”

“In orbit around what?”

“Chandra,” said Bilson simply.

Pirius, for all his fatigue, felt a thrill of anticipation.

Blue called, “And what is that cloud around the star? Dust, rock—”

“Wreckage,” Bilson said. “The hulks of human ships — greenships, Spline. Some other designs I can’t recognize. Older ones, perhaps.”

Burden said grimly, “Even here the Galaxy is littered with corpses.”

“Xeelee in the scopes,” Bilson said softly. “They know we’re here. Pilot, we don’t have much time.”

“So we’re not the first to come this way,” Pirius said crisply. “Let’s make sure we’re the last. Defensive formation, seven-fold — come on, you know the drill.”

The greenships slid into place around him and the squadron edged forward. Pirius scanned the sky, looking for Xeelee fighters, and for Chandra, the strange black hole that was his final destination.

Chapter 55

In this age of matter the proto-Xeelee found new ways to survive. Indeed, they prospered. They formed new levels of symbiosis with baryonic-matter forms. The new form — a composite of three ages of the universe — was the kind eventually encountered by humans, who would come to call them by a distorted anthropomorphic version of a name in an alien tongue: they were, at last, Xeelee.

But soon the new Xeelee faced an epochal catastrophe of their own.

They still relied on the primordial black holes, formed in the earliest ages after the singularity; they used the holes’ twisted knots of spacetime to peel off their spacetime-defect “wings,” for instance. But now the primordial holes were becoming rare: leaking mass-energy through Hawking radiation, they were evaporating. By the time humanity arose, the smallest remaining holes were the mass of the Moon.

It was devastating for the Xeelee, as if for humans the planet Earth had evaporated from under their feet.

But a new possibility offered itself. New black holes were formed from the collapse of giant stars, and at the hearts of galaxies, mergers were spawning monsters with the mass of a million Sols. Here the Xeelee migrated. The transition wasn’t easy; a wave of extinction followed among their diverse kind. But they survived, and their story continued.

And it was the succor of the galaxy-center black holes that first drew the Xeelee into contact with dark matter.

There was life in dark matter, as well as light.

Across the universe, dark matter outweighed the baryonic, the “light,” by a factor of six. It gathered in immense reefs hundreds of thousands of light-years across. Unable to shed heat through quirks of its physics, the dark material was resistant to collapse into smaller structures, the scale of stars or planets, as baryonic stuff could.

Dark and light matter passed like ghosts, touching each other only with gravity. But the pinprick gravity wells of the new baryonic stars were useful. Drawn into these wells, subject to greater concentrations and densities than before, new kinds of interactions between components of dark matter became possible.

In this universe, the emergence of life in dark matter was inevitable. In their earliest stages, these “photino birds” swooped happily through the hearts of the stars, immune to such irrelevances as the fusion fire of a sun’s core.

What did disturb them was the first stellar explosions — and with them the dissipation of the stars’ precious gravity wells, without which there would be no more photino birds.

Almost as soon as the first stars began to shine, therefore, the photino birds began to alter stellar structures and evolution. If they clustered in the heart of a star they could damp the fusion processes there. By this means the birds hoped to hurry a majority of stars through the inconvenience of explosions and other instabilities and on to a dwarf stage, when an aging star would burn quietly and coldly for aeons, providing a perfect arena for the obscure dramas of photino life. A little later the photino birds tinkered with the structures of galaxies themselves, to produce more dwarfs in the first place.