“Is a time machine.” Every child learned that before she got out of her first cadre.

“I pulled away. Out of trouble, I watched the flare unfold, recorded it. I took my time to work out your optimal path—how you would have avoided destruction if you’d had the time to figure it out.”

Pirius said, “But it was academic. You got the answer after we were already dead.”

“And I had to watch you die,” said Dans wistfully. “When the action was over, the Xeelee out of the way, I used my sublight to ramp up to about a third lightspeed. Then I cut in the FTL.”

Cohl understood; “You jumped back into the past—to the moment just before we hit the flare. And you fed us the maneuver you had worked out at leisure. You used time travel to gain the time you needed to plot the trajectory.”

“And that’s the Brun maneuver,” Dans said with satisfaction.

“It’s some computing technique,” Cohl mused. “With the right vectors you could solve an arbitrarily difficult problem in a finite time—break it into components, feed it back to the source. . . .”

Pirius was still trying to think it through. “Time paradoxes make my head ache,” he said. “In the original draft of the timeline, Claw was destroyed by the flare, and you flew away. In the second draft, you flew back in time to deliver your guidance, and then you—that copy of you—flew into the neutron star.”

“Couldn’t be helped,” Dans said.

He could see she was waiting for him to figure it out. “But that means, in this new draft of the timeline, we survived. And so you don’t need to come back in time to save us. We’re already saved.” He was confused. “Did I get that right?”

Hope said, “But there would be a paradox. If she doesn’t go back in time, the information that future-Dans brought back would have come out of nowhere.”

Cohl said, “Yes, it’s a paradox. But that happens all the time. A ship comes limping back from a lost battle. We change our strategy, the battle never happens—but the ship and its crew and their memories linger on, stranded without a past. History is resilient. It can stand a little tinkering, a few paradoxical relics from vanished futures, bits of information popping out of nowhere.” Cohl evidently had a robust view of time-travel paradoxes. As an FTL navigator, she needed one.

But Pirius’s only concern was Dans. “So can you save yourself?”

“Ah,” Dans said gently. “Sadly not. More than one Xeelee chased us after all. If I hadn’t hung around to work out your course I might have got away. I’m all that’s left, I’m afraid. Little pixellated me . . .”

“Dans”—Pirius shook his head—“you gave your life for me. Twice.”

“Yeah, I did. So remember.”

“What?”

She glared at him. “When you get back to Arches, leave my stuff alone.” And she popped out of existence.