“These days there is biotechnology, and a science called epigenetics that has to do with how genes express themselves, but we don’t have anything like this . . . We’re not necessarily at the peak of all knowledge now, though, like people tend to think we are. Who knows what was possible then.”

   We looked out the front window again.

   “What if they can’t deactivate it?” I said, unable to hold it back anymore. “Now, if they capture us, they have everything they need. And the only way to destroy the cure . . .”

   “No,” he said. I’m sure we’d all thought it, even if no one would admit it. How much was one girl’s life really worth, when the alternative was this terrible?

   My own grubby hair clung damply to my neck. I pulled it back. “I’m not saying it should be Plan A, but if it’s me or half the world? Do the math.”

   “We’re going to figure something out,” he said firmly. I almost believed him.

   For a while we stared out the window, watching the miles go by and the headlights approach and zoom past. Driving in a musty van toward the unknown felt like half my childhood. Funny that that was comforting now, when I started off every one of those drives in tears over yet another last-second move. By a couple hours in, though, my mom would always make it better. She’d stop at a gas station, we’d buy whatever weird regional snack we could find, and we’d sit in the parking lot and speculate about our new home.

   I wasn’t used to these intrusive memories being nice ones. I felt Stellan looking at me. I told him what I’d just been thinking. “And she’d do what she always did when I was upset. She would . . . pet me. Just rub my back, or my hair, like I was a scared puppy. I always calmed down. Is that weird? I don’t know why I just told you that.”

   He shrugged and stretched his legs into the space between the driver’s and passenger’s seat. “I don’t know why I tell you a lot of things.”

   “I could have saved her,” I whispered. “The cure is my blood. I was right there.”

   “You didn’t know,” he said.

   “I loved her so much.”

   He pulled his feet back in. Headlights from an oncoming car slanted across his face. “I know.”

   “You don’t.” Outside was flat as far as I could see, dotted with shadows I knew were scrubby bushes, and lights in the distance. It was like voicing one of the concerns I’d had since the tomb, and then letting myself talk about my mom, had opened a floodgate. Or maybe it was Stellan. I had a definite tendency to overshare with him in a way I never did with anyone else. Maybe Jack was right and the two of us understood things no one else really could. “I had no other family. We weren’t anywhere long enough for me to find people I cared about, and if I did, we left them. She was all I had, and even though I loved her, I spent a lot of time resenting her for that.”

   Out of the corner of my eye, I saw Stellan turn in his seat to watch me.

   “I’m sorry. I know that sounds whiny and that all you guys had childhoods so much worse; this doesn’t even compare.” I had barely let myself think these things, but now I couldn’t stop. You could say things in the dark that weren’t okay in the daylight, I guess. Studying the broken headrest of the passenger’s seat in front of me, I went on. “When she got kidnapped, I felt so horribly guilty, and at the same time, I almost blamed her. I couldn’t help but wonder what would have happened if she’d told me the truth so I wouldn’t have stumbled into it blind like I did.”

   I squeezed my locket so hard, my fingers hurt. “When we got her back, I didn’t even take advantage of the time I had with her. I think I was still a little angry. And now she’s dead. My mom is dead. I should be able to just be sad like a normal person, but I can’t.” Jack saying it on the bus had made me realize it. If I was just sad, everything would be so much easier. “I feel guilty because it was my fault. And angry because it was partly hers. And then so guilty again, about being angry.”

   Stellan started to say something, but I wasn’t done. “And on top of it all, I feel so disgusted with myself over everything. Over how I feel about my mom. Over how I don’t even feel bad that Cole is dead. He’s my half brother, and he’s dead, and I’m glad, and that’s disgusting. I can’t believe I feel those things. I don’t even recognize myself.”

   Before I even realized I was shaking again, Stellan’s hand was gently cupping the back of my neck, his thumb running over my hair. “Like this?” he said quietly.

   I tensed. I should want him to stop. I didn’t. “Yeah.”

   “Is this weird?” he said after a second.

   “Yeah.”

   “Good weird?”

   I nodded.

   “You don’t have to keep making up ridiculous excuses like panic attacks to get me to touch you, you know.” One side of his mouth tugged up. “All you have to do is ask.”

   “Shut up,” I whispered, but he didn’t stop petting my head, and I didn’t tell him to. The shaking calmed. For some reason, I remembered that night on the train from Paris to Cannes. He’d had a head injury, I’d helped him take care of it. The next morning, we’d woken up accidentally wrapped together in my bed, with Jack sleeping next to us.

   I glanced to the back seat at Jack and Elodie’s slumbering forms. “So have you talked to your sister again?” I said, changing the subject abruptly.

   His fingers paused. “Before we went into the tunnels. They’re at the safe house. They’re fine.” He gave a wry smile. “The nanny told me to stop calling so much. I was making Anya nervous.”

   I pulled my knees up to my chest. “I’m glad she’s okay.”

   He nodded. His hand trailed off my back and he turned to stare out the window. I realized he’d never answered the question of how he knew what a panic attack looked like, and exactly what to do. I realized I’d been doing a whole lot of talking about myself.