Mom chimes in. “If you’re not going to be useful in the kitchen, come here and help me work out these formulae for a thirty-dimensional sphere.”

“You know what?” Theo claps his hands together. “Sounds like a good day to learn to cook.”

Dad peers around the corner, his face barely visible above Mom’s exuberant philodendron. “Have both of you gone mad simultaneously?”

“Yeah,” Theo says, “it saves time.” That makes Dad laugh; more important, it makes him turn back to what he was doing, so Theo and I have some privacy.

The two of us start layering noodles, sauce, and cheese in the glass baking dish. Everything goes smoothly. No curling pasta, no giggling, no Paul at my side. It’s less fun this way.

As we work, I tell Theo in a low voice what I learned during those last moments in London. “If Paul had done it, there’s no way he could have looked so surprised. He honestly didn’t know.”

“My response to that rhymes with shull-bit. Come on. You’re too smart to be fooled that easily.”

Stung, I whisper, “You didn’t see him. I did.”

“I don’t have to see Paul’s face to know what he’s done. You think you’re too smart to be lied to? He fooled your parents the geniuses, so I’m pretty sure he could fool you, too.”

I can’t accept that. I can’t. If I know anything about Paul Markov, I know he’s not evil enough to murder my dad. And if I owe the Paul from Russia anything for loving me, and saving my life, I owe his other selves the benefit of the doubt.

“He didn’t betray us,” I say. “And I won’t betray him again by doubting him.”

Theo sighs as he starts spooning on another layer of ricotta. “You’ve got a tender heart, Meg. You get angry quick, and you simmer down quick, too. I love that about you, but this is not the time to keep changing directions. The world keeps shifting around us; that means we have to hold on to what we know.”

“We don’t know anything. We didn’t even stick around for the funeral. They might have learned more once they were able to—” To examine the body. To perform an autopsy. I can’t even say those words aloud while thinking of my father. “Besides, in Russia, Paul died to save me. I don’t think he’s the villain here.”

I remember coming to in the dacha, lying in Paul’s arms. His whisper echoes inside my head: Golubka. Little dove.

Some flicker of what I’m feeling must show in my face, because Theo gets even more intense. “Okay. So Paul Markov isn’t a son of a bitch everywhere. Infinite dimensions equal infinite possibilities. There’s probably even a dimension where I’m not instantly desired by every woman I meet.” The joke doesn’t do much to lighten either of our moods. He continues, “Seriously. Anything can happen. Everything has to happen, in one dimension or another. So there has to have been a decent Paul somewhere. You met him. Congrats. But the Paul we’re dealing with on this trip? That Paul? He screwed us over, and he wants to do it again. Don’t let him. Don’t go soft on him now.”

It doesn’t feel like I’m going soft. It feels like I’m holding firm. “I just don’t believe he did it, Theo. He admitted wiping the data, and of course he stole the Firebird, but—”

“So he confessed to everything but the murder, and that’s all it takes to get back on your dance card?” Theo runs one hand through his unruly black hair, obviously trying to calm himself. “This is hard for me too, by the way. I loved Paul. I always thought—you know, we’d wind up on the same faculty at Cambridge or Caltech, be mad professors together.” His smile is wistful, and fleeting. “In some dimension, I guess we’ll get to do that.”

“Even you see it,” I say, ladling on the final layer of tomato sauce. “You know Paul’s not a bad guy. He must have had a good reason for everything he’s done.”

Theo sighs, and the look on his face is that of a man fighting a lost cause. “Take some time here, while we’re safe and things aren’t too weird. Think this over. Really think. And just remember, the man Paul could be doesn’t matter nearly as much as the man he actually is.”

I know Theo genuinely wants to protect me—but I know he’s also realized that Paul and I became close in Russia. He doesn’t know exactly how close, but he’s guessed enough of the truth to be upset.

To be jealous.

When Theo’s eyes meet mine, I see that he knows everything I’ve been thinking. One corner of his mouth curves upward, like he wants to smile but can’t quite manage it. “I never claimed to be objective about you, Meg.”

“I need you to be objective about Paul.”

“One of us is being objective about Paul already,” Theo answers. “Guess we have to figure out which one. But it’s a high-stakes game. Bet on Paul, get it wrong—and we both might pay with our lives.”

20

THE KITCHEN DOOR SWINGS OPEN, AND THEO AND I LOOK up to see Josie standing there wearing a Coronado Island T-shirt and a backpack slung over her shoulders.

She grins wickedly. “Am I interrupting something?”

We were having a serious conversation about a murder in another dimension, that’s all, but that’s not an explanation my big sister needs to hear. Besides, right now, I’m just too glad to see her.

“Hey, you.” I go to Josie and hug her as tightly as I can with the backpack in the way. “Welcome home.”