At first, neither of us knows what to say, and he can’t hold my gaze very long. I look at his T-shirt because it’s less awkward than looking at his face—and then I realize I know a couple of the members of The Gears. “Wait. That’s Paul McCartney and George Harrison, but—who are the other guys?”

“No freaking clue.” Theo holds his shirt out as he glances down. “Apparently they never met John Lennon, or even Ringo Starr, so the Beatles never quite happened. These guys seem to have been pretty famous on their own, though.”

No Beatles in this universe. It makes me sad, the nonexistence of a band that broke up decades before I was born. I know all their songs word for word, thanks to my father. Dad was the biggest Beatles fan ever. His favorite song was “In My Life,” and he’d hum the verses while he washed up after dinner.

The memory stings—and I hate that, I hate how all the good memories have turned into things that hurt—but I need the pain.

Aunt Susannah’s blow-drying her hair, so we’re able to escape from the apartment without any more vomit-worthy flirtation between her and Theo. As the elevator takes us back to ground level, I try to get our plans together. “All right. First we have to figure out whether or not Paul’s left Cambridge—”

“Forget it.” Theo slips on his jacket. “If he’s still in Cambridge, he’s not the Paul Markov we’re looking for. If Paul leaped into this dimension, if he’s in this version of Paul, then he’s on the move. Promise.”

That seems like a big assumption to make. “Do you know something I don’t?”

“I know Paul had been acting borderline paranoid about Triad Corporation the last couple of months,” Theo replies. “Like the guys who were funding us would’ve sabotaged the research they paid for. Makes no sense, right? But I guess now we know Paul wasn’t . . . thinking clearly. Let’s put it that way.”

Maybe that’s the secret: Paul spent the past few months slowly going crazy. We thought he was acting normally, but he was always so quiet, so introverted, that there was no telling what might be going on inside. “That makes sense. But how does it help us?”

“Triad Corporation may be one of the world’s biggest tech companies, but everybody knows it all boils down to one guy—Wyatt Conley.” Triumphant, Theo holds up his wrist and projects a holographic image of a news story in front of us. The newness of the technology fades as I read the headline: CONLEY TO SPEAK AT TECH CONFERENCE IN LONDON.

“He’s here,” I say as I read the date. “Wyatt Conley is in London today.”

“Which means we don’t have to find Paul. We find Conley—because if our Paul is here, he’s going after Conley first.”

Stands to reason Conley would be a tech genius here, too. He’s only thirty, but he’s considered one of the giants—mostly because he developed the core elements of the smartphone when he was only sixteen. Triad is probably the most prestigious corporation in the world, has a glitzy, ultramodern office under construction not far from my home in the Berkeley Hills, and makes the kind of gadgets and gear people stand in line for for two or three days before they’re released. Personally I think it’s kind of stupid to get that worked up over a phone that’s, like, two millimeters thinner than the last one, but I don’t knock it, because Triad’s R&D money made Mom’s work possible.

I guess Paul turned against everyone who ever helped him, all at once.

The elevator doors slide open, and we walk out through the chic mirrored lobby. I smile at the doorman as we go out, cool December air ruffling my hair and Theo’s jacket. The doorman seems surprised; I don’t think this Marguerite spends a lot of time being nice to people. Once we’re alone again, I ask, “How do you know Paul’s not coming after us first?”

Theo shrugs. “I don’t. But either way, we don’t have to waste time looking for him. The fight’s coming to us.”

The tech conference is being held at a super posh hotel in the center of the city. Theo and I head in on one of the shimmering monorails that slithers over the crowds below.

“How do we get in?” I ask as we sit on the plastic seats. Above our heads, holographic ads glitter and dangle like hallucinogenic Christmas ornaments. “Tech conferences like this don’t sell tickets at the door, do they?”

“Hell, no. If Wyatt Conley’s the keynote speaker, this thing probably costs a thousand bucks a head.”

My eyes widen. I have more money in this dimension, but that’s a lot—and anything that expensive probably sells tickets in advance, not in person. “What are we going to do?”

“We’re going to sneak in.” He gives me a sidelong look, and he smiles. “Since I’m the one with the criminal instincts on this team, leave that part to me, all right? Once we get past the main entry area, nobody’s going to look twice at either of us as long as we play it cool.”

The people at this conference are going to be corporate tycoons, millionaires, and so on, but Theo’s wearing beat-up jeans, a parka, and a T-shirt. “What about your clothes?”

“You’re the one who’s dressed wrong for a tech conference—not that you don’t look as sensational as ever.” He’s as cocky as he ever was, like I didn’t see him stoned and helpless on the bathroom floor an hour ago. Is that infuriating or a relief? Theo gestures to his beat-up jeans. “I’m probably slightly overdressed as it is, but I can get away with it. Just stick close to me, okay?”