“What? How do you know that?”

“You’re not the only one who’s used a computer before, you know. I tracked Paul down at Cambridge.”

I look through the night at the harsh cityscape across the river, where the jagged dark outlines of skyscrapers dwarf the dome of the cathedral. Paul might be here already. How long would it take him to reach London?

Fiercely I remind myself that if Paul’s chasing me, it saves me the trouble of chasing him. The next time we meet, one of us is going to be sorry, and it won’t be me.

I must look murderous, because Theo says, “We have to remember one thing, okay? There’s a slim chance I calibrated wrong. We could have jumped into the wrong dimension. The Paul Markov in this dimension might not be our Paul. So we can’t overreact until we know the facts.”

What he’s really saying is, I can’t kill an innocent man. I’m not even sure I can kill the guilty one, though I mean to try. My limited skills with the Firebird mean I can’t tell the difference between our Paul and any other; it’s just one more reason I need Theo with me.

“How fast can you get here?” I ask.

Theo gives me that sly grin of his. “Already bought my ticket, Meg. Couldn’t take my pick of flights, traveling last minute—gotta go all the way to Germany and back again, so thanks, Lufthansa—but I should be there by midnight tomorrow. Fast enough for you?”

He’s already crossed a dimension to help me; now he’s going to cross half the globe, as fast as humanly possible, and the one thing Theo asks is whether he’s doing it all fast enough. I whisper, “Thank you.”

“We’re in this together,” Theo says, like it’s no big deal. “Listen, if I’ve figured these ring-phone things out, and I think I have, you can give me tracker access.”

“What is that?”

“Hold your ring up to the hologram, okay?” I do it. The ring glitters, and in the holographic screen, I can see his ring light up as well. Theo grins. “Good. Now I can find you any time you’ve got that ring on, or you can find me. Once you figure out the interface, that is. Okay, where are you headed?”

“Home, I guess. Once I figure out where it is.” I laugh. Suddenly Theo looks stricken. Why should he look like that?

“Marguerite—” His voice is very quiet, very serious, not like the usual Theo at all.

Fear flickers stronger within me, and quickly I search for HENRY CAINE AND SOPHIA KOVALENKA. Results pop up instantly: physics papers, a few faculty photos from when they were younger, and video clips.

Video of the hovership accident from years ago, the one that killed three dozen people, including two promising scientists and their older daughter.

I don’t have Dad back. He’s dead here too. The only difference is that Mom is gone too. And Josie.

My whole family is dead.

I suck in a breath, hard, as if I’d been struck. As though at a great distance, I hear Theo’s voice say, “Marguerite? Are you okay?”

I don’t answer. I can’t.

The holographic screen helpfully starts showing me the video of the wreck, which apparently was a big thing on the news. Right now it feels like that explosion is happening inside my head, white heat and blinding light and everything I love, everyone who really loved me—Dad and Mom and Josie—burning to cinders.

It happened above San Francisco. The news articles say bits and scraps of the wreckage turned up as far away as Las Vegas, drifting down to earth, sometimes washed down with the rain.

“Marguerite?” The shimmering of the hologram doesn’t hide the concern on Theo’s face. “Your folks—I’m sorry. I’m so sorry. When I came to in this dimension, I looked them up first thing—thought they could maybe help us, you know? I didn’t realize you hadn’t learned what happened to them yet.”

My heart has been crying out for Dad, over and over, since the moment the police called our house. I’d even cherished a small hope of seeing him again here, at least a version of him.

But he’s still gone, still dead, and now Mom and Josie are as lost as he is.

They’re fine! I try to tell myself. That happened in this dimension, but not yours. When you go back home, Mom and Josie will be there waiting for you—it’s not like here, you didn’t lose everything, not absolutely everything—it’s going to be okay—

But it’s not. Dad is still gone.

“Why does anybody want to travel through dimensions, anyway?” I choke out. My fingernails dig into the flesh of my forearms, which are crossed in front of me like a shield. The physical pain keeps me from crying; no matter what, I refuse to cry. “They haven’t thought enough about what they might find.”

“I’m sorry,” Theo repeats. He looks like he wants to step forward through the hologram to get to me. “I’m so sorry.”

I think, Is this what you wanted, Paul? Did you hate them so much that you ran to a world where they were already dead? So your work would be done for you?

Once again I remember Paul’s unsmiling face, his gray eyes that seemed to stare through me. I remember the day he watched me painting, his gaze following every stroke my brush made on the canvas. It sickens me now to think that for a little while I almost—

Theo speaks again, his voice firmer this time. “That accident was a long time ago, and a lifetime away. You’ve gotta think of it like that. All right?”

His words break through my melancholy, bring me back to the now. “All right. Yes. It was just a shock. I won’t let it get to me again.”