“When we were Evoked,” I reminded him, “you said there was a rumor we’d just get taken off to a gas chamber.”

“Indeed,” he said, “but I was envisioning something much simpler—quicker—less expensive.”

It was the kind of joke that would only be ruined by my laughing out loud. I somewhat wished that Jesry and Lio could be in on it. But indeed, before too much longer, our conversation flagged. Arsibalt disconnected from me and began making the rounds, as if table-hopping in the Refectory.

He was connected to Jesry when Jesry applied power to the tether. This was a simple matter of pumping electrical current down the wire to its far end. Of course, in order to make an electrical circuit, there had to be some way for those electrons to get back up to the nuke. Normally that would have been provided by a second wire, parallel to the first—as in a lamp cord. Here, though, that would have defeated our purposes. Fortunately we were in the ionosphere—the extreme upper atmosphere, permanently ionized by the radiation of the sun, so that it conducted electricity. We got the return path for free. Current only flowed in one direction along that wire. Consequently, it interacted with Arbre’s magnetic field in such a way as to generate thrust. Not a lot of it—not like a rocket engine—but, unlike a rocket engine, we could run it continuously for days, and gradually spiral in to the desired orbit: still, all this time later, the orbit that Ala and I had watched the Daban Urnud settle into by following a trail of sparks across a page in the Præsidium.

As long as Arsibalt was hard-wired to Jesry, he acted as communicator to the rest of us, getting our attention with sweeping arms and pantomiming a suggestion that we all grab on to something. Then he counted down with his finger. At “five,” one of his skelehands became redundant and he used it to grasp a bracket on the control panel of the nuke. At “one” he grabbed the bracket with his other hand as Jesry flipped a switch. The result was not dramatic, but it was perfectly obvious: we saw the tether adopt a slight bow, just like a taut string being acted on by wind. As it did, the Cold Black Mirror yawed around slightly and settled into a new angle, no longer looking straight down at the surface of Arbre but now canted almost imperceptibly sideways. And that was the whole event. We were under thrust now, as surely as if Jesry had fired a rocket engine. It was, though, a thrust too subtle for our bodies to feel it, and it would have to act on us for days to have any effect.

Once that had been done, I had a few moments to think about what Arsibalt had been saying. Even taking into account Jules’s and Jad’s medical troubles and my nuke escapade, it had to be said that the launch and the assembly of the Cold Black Mirror, the firing of the decoy and the deployment of the tether had all gone better than we’d had any right to expect. No one had turned up dead, or mysteriously failed to turn up at all. There’d been no accidents—no one drifting helplessly away—we’d recovered as many of the payloads as we needed. Since that had seemed like the most obviously fatal part of the journey, it had put me in too sunny a mood. But ten seconds’ reflection sufficed to make it obvious that this was a suicide mission.

Social conventions evolved. I’d thought some might take it the wrong way if two or three of us jacked together for a private conversation. But I didn’t feel thus when I noticed Lio talking to Osa or Sammann to Jules Verne Durand, and soon it became clear that everyone in the cell was happy to afford others privacy. Sammann strung a network of wires through the frame that everyone could connect to when it was necessary to have an all-hands meeting, and we agreed that we’d do so every eight hours. The intervals between those meetings were free time. Each of us tried to devote one out of three to sleeping, but this wasn’t going so well. I thought I was the only one having trouble with it until Arsibalt drifted over during a rest period and connected himself to me.

“You sleeping, Raz?”

“Not any more.”

“Were you sleeping?”

“No. Not really. How about you?”

Up to this point it had been the same, word for word, as the conversations we used to have in the middle of the night back when we had been newly Collected fids, lying in unfamiliar cells, trying to sleep. Now, though, it took a new turn. “Hard to say,” Arsibalt said. “I don’t feel as if I am going through normal sleeping and waking cycles up here. Frankly, I can’t tell the difference between dreaming and waking any more.”

“Well, what are you dreaming about?”

“About all that could have gone wrong—”

“But didn’t?”

“Exactly, Raz.”

“I haven’t heard the whole story yet of how you rescued Jad.”

“I’m not even certain that I could relate it coherently,” he sighed. “It exists in my mind as a jumble of moments when I thought or did things—and every one of those moments, Raz, could have gone another way. And all of the other outcomes would have been bad ones. I’m certain of that. I replay it in my head over and over. And in every case, I happened to do the right thing.”

“Well, it’s kind of like the anthropic principle at work, isn’t it?” I pointed out. “If anything had been a little different, you’d be dead—and so you wouldn’t have a brain to remember it with.”

Arsibalt said nothing for a while, then sighed. “That is as unsatisfactory as anthropic arguments usually are. I’d prefer the alternate explanation.”

“Which is?”

“That I’m not only brilliant, but cool under pressure.”

I decided to let this go. “I’ve had dreams,” I admitted, “dreams in which everything is the same, except that you and Jad aren’t here because you croaked.”

“Yes, and I have had dreams in which I let Jad go because I couldn’t drag him back, and watched him burn up in the atmosphere below me. And other dreams in which you didn’t make it, Raz. We recovered the nuke, but you had simply vanished.”

“But then you wake up—” I began.

“I wake up and see you and Jad. But the boundary between waking and dreaming is so indistinct here that sometimes I can’t make out whether I’ve gone from dreaming to waking, or the other way round.”

“I think I see where this is going,” I said. “I might be dead. You might be dead. Jad might be dead—”

“We’ve become like Fraa Orolo’s wandering 10,000-year math,” Arsibalt proclaimed. “A causal domain cut off from the rest of the cosmos.”

“Whew!”

“But there is a side effect that Orolo never warned us of,” he continued, “which is that we’ve gone adrift. We don’t exist in one state or another. Anything’s possible, any history might have happened, until the gates swing open and we go into Apert.”

“Either that,” I said, “or we’re just sleepy and worried.”

“That is just another possibility that might be real,” Arsibalt said.

When we weren’t (according to most of us) dozing or (according to Arsibalt) drifting between distinct, but equally real, worldtracks, we were studying the Daban Urnud. A few paragraphs’ worth of description from Jules Verne Durand, disseminated over the Reticulum, had given the Antiswarm enough information to build a three-dimensional model of the alien ship that, according to the Laterran, was eerily faithful.

Blow a balloon out of steel, almost a mile wide, and fill it half full of water. Repeat three more times. Place these four orbs at the corners of a square, close to one another, but not quite touching.

Repeat with four more orbs. Stack the new set atop the old. But give it a forty-five-degree twist, so that the upper orbs nestle into the clefts between the ones below, like fruits stacked at a green-grocer’s.