He wondered what she was feeling. This strange, cold woman from Earth had been on her own journey, he supposed. He said, “I couldn’t have done it without you, Pila. I won’t forget that.” He turned to Nilis and said formally, “Commissary — I was glad to have taken part in the final experiment that proved your theories.”

That took Nilis by surprise. “Oh, my boy, my boy. Thank you! And you validated my faith in you, in spades. You have come a long way from that mixed-up child on Port Sol and Venus, my boy, a long, long way. You are a man — you poor wretch!

“And of course it has been a great technical achievement.” He smiled, his rheumy eyes wet. “Who would have thought, when we were limping around in Sol system, that we could have brought it off? Well, I always had faith in you, Pirius; I knew you could do it, if anybody could.”

“And we made history today.”

“Oh, yes, there’s that too. How remarkable to think that of all the galaxies we see in the sky, only ours is clear of the Xeelee — and all thanks to human endeavor! And it is a historic moment in other ways. It’s a fallacy, you know, that communication is always possible between alien cultures. The dismal records of the Assimilation prove that. Sometimes perceptions of our common universe simply diverge too much. In an awful lot of first contacts, ’communication’ is primal: only to be ignored, eaten, or attacked. And there is no record of the Xeelee attempting any form of communication with any lesser species, save extreme violence. But in this incident they did respond. We threatened Chandra, they withdrew, we did not attack; information, of a sort, passed between us, and a kind of agreement was reached.” He sighed. “If only it were possible to build on this breakthrough! Perhaps the perpetual war could be ended. But I fear that may be Utopian.”

Pirius knew how important this sort of philosophical stuff was to the Commissary. “A triumph in many ways, then.”

“Yes.” But Nilis’s face crumpled. “But too many people were lost — too many young lives rubbed out because of me and my dreams. Those moments when the first two runs failed, and I thought that despite the sacrifices I had demanded, I had failed, were almost more than I could bear.”

Pirius tried to find words about the proportionality of the losses compared to what had been gained. But Nilis, he saw, was inconsolable for now. After a time he left him to his work.

In their barracks, Torec was already asleep. She hadn’t even taken off the coverall given her by the medics after they peeled her out of her skinsuit. Pirius crawled in with her. She stirred, mumbled, and turned into his arms, a bundle of soft warm humanity.

He had thought he would be too agitated to sleep. Besides, he felt guilty about lying down to sleep when others had died, or were still out there. If he slept, this long day would finally end, and he would somehow lose it, lose them.

But sleep rose up like a black tide, regardless.

The next day, his first priority was his crews.

He toured the base. They were in their barracks, or the refectories, or the sick bays, or the gyms and training rooms where they had gone to work out the tension from their systems. A couple of them had gone back to the ships to help the ground crews with their own investigations and debriefing.

Some just accepted what had happened. It was a gamble worth taking, they said; you win some, you lose some. Others were bitter at the stupidity of the commanders, including Pirius himself, who had sent them into the Cavity with such poor intelligence. He absorbed their anger. And some just talked. They went over and over what they had done, telling and retelling their own small war stories as part of the whole. That was all right. It was part of the healing, and Pirius’s job now was to listen. And it wasn’t going to stop here, he knew. The shock of what they had gone through, and the guilt at having survived where others hadn’t, would never leave them.

Pirius had lost a temporal twin, a part of himself, and he wondered which way his own damage would work out — and how Torec, who had lost her lover and welcomed him home at the same time, would sort out her own complicated, guilt-ridden grief.

More than twenty-four hours after Pirius’s return, This Burden Must Pass brought his own battered ship home.

Pirius hurried to meet him, and walked with his crew to the sick bay. With his visor cracked open, Burden’s face was drawn, dried sweat was crusted under his shadowed eyes, and his hair was plastered to his head. Burden said that they had encountered no Xeelee harassment on the way back. “It looks as if it really is true,” he said. “They have abandoned the Galaxy to mankind. And because of us.”

“Quite a story to add to that end-of-time confluence of yours,” Pirius said.

“Yes, quite a story.” Burden said more slowly, “Pirius. About what happened out there—”

“Forget it,” Pirius snapped.

“I can’t do that,” Burden said. “If I’d gone into Chandra as you ordered, as was my duty, maybe Blue would have survived.”

“We’ll never know. We’ve all come home with regrets, Burden. Now we move on.”

Burden nodded, his eyes downcast. “We move on.”

Burden said he had found no traces of Jees’s lost ship. “It was smashed up. Two of the crew nacelles, more or less intact. But the systems had failed before the safety cut-ins could work.”

“They didn’t survive.”

“We sent the crew blisters into the black hole.” Burden smiled thinly, exhausted. “It seemed fitting.”

“That it does.” Pirius was thinking over what Burden had said. His thoughts were muddy; already the events of the flight seemed remote, as if they had happened a decade ago, or in another life. But there was something missing from Burden’s report. “You didn’t mention the third nacelle. Jees rode with the Silver Ghost.”

Burden grinned. “I wondered if you’d ask about that. I’ll have to report it, I suppose. Of the Ghost’s nacelle I found not a trace. Not only that, it looked to me as if it had been sheared off — I mean, deliberately.”

“The Ambassador escaped,” Pirius said, marveling. Once more there was a Silver Ghost loose in the Galaxy. “But what different can one Ghost make?”

“The Ghosts are remarkable creatures, and very resourceful. I don’t think we’ve heard the last of the Sink Ambassador. And you have to wonder if, from the Ghost’s point of view, this whole operation was set up — if we were set up — just to give the Ghost a chance to get free.”

“That’s impossible.”

Burden glanced around. “I’m not going to repeat this in the debrief. But I want to go back out there again.” He spread his gloved hands. “After all, the war is over, it seems. They don’t need me to fight any more. Not that I was much use at that in the first place. I want to go back to the center again, to look for the Ambassador.”

“Why?”

“Because we never finished our philosophical discussions. Things are different now. Perhaps we can learn from the Ghosts about how we’re going to live our lives from now on. Oh, Pirius — one more thing.” He dug out a data desk and showed him some complicated schematics. “Something the sensors picked up.”

Burden had observed structures of dark matter drifting through the center of the Galaxy. Invisible to human senses, passing through even the crowded matter around Chandra as if it was no more substantial than a Virtual, the shadowy forms had settled around the central black hole.

Burden said, “I remember what you said about Nilis, and Luru Parz, and their interpretation of history. The Xeelee cleaned these dark matter creatures, the ’photino birds,’ out of the Core. Now the Xeelee are gone — and in less than a day the birds are back.” He put away the data desk. “Silver Ghosts loose, dark matter creatures swarming through the Core — we have planted many seeds, as Nilis would say. Something tells me the future suddenly got a lot more complicated.”