Dad goes into professor mode. “Now, Marguerite, what do you know about information? What is the most peculiar thing about it?”

Maybe that sounds like a really broad question, but I understand what he’s driving at. “Information is the only thing we know of capable of moving faster than the speed of light. The universe knows things it shouldn’t know, before it should be able to know them. Like—like when a quark is destroyed, and another is created instantly to take its place.” Paul told me this, too, as we stood in the redwood forest, looking up into infinity.

“Exactly,” my mom says. “Transferring consciousness—as exciting as it would be, and as revolutionary as it would be even to identify and isolate consciousness—it’s not the best way of learning more about the other dimensions of the multiverse. We can structure ‘messages’ in the form of asymmetrical subatomic sequences and see how other quantum realities respond.”

“If we figure out how best to handle this, we might even be able to speak directly to other versions of ourselves—or, at least, to the other scientists doing our kind of work,” my father adds. “Much better than popping into someone else’s body unannounced.”

I think of the Grand Duchess Margarita, even now hiding out in a Danish country house until she gives birth to a baby—one I conceived for her. Of a Theo in New York City who’s still in the hospital, wondering if he’ll ever be able to walk again. Of Lieutenant Markov dead in my arms. I admit, “The ethics are a lot better.”

Mom nods, but I can tell to her this is only a theoretical consideration, one she’s never had to truly face. “We’ll have far better reach, as well. Instead of only visiting universes where we ourselves exist, we should be able to learn something about virtually any dimension in the multiverse— Henry. Stop giving noodles to the dog.”

“He likes noodles,” Dad says, as Ringo slobbers down his one strand of spaghetti.

My parents the illustrious scientists begin debating whether or not pasta gives the dog gas. It offers me a moment to consider what I’ve just learned, the possibilities expanding in my mind every moment.

The Home Office and the Triadverse must have dismissed this dimension as a threat because Mom and Dad abandoned the Firebird project. What Conley never realized was that they would instead turn their attention to another way of contacting other universes. If we got that power—my world, and the Warverse, and even the Paul and Theo from the Home Office—and we could communicate with each other constantly, without the risks of jumping dimensions . . . we could form an alliance much larger than Triad’s conspiracy. Much more powerful. We could prepare ourselves against any attack the Home Office could make.

This could be how we take them down.

As precious as the treatment for Theo is, as eager as I am to rescue my own Paul, I now know I’m bringing home a third treasure—or, at least, a chance. The coordinates to this dimension could save us all.

“How long?” I ask.

Mom huffs, “Until the dog begins stinking up every room he’s in? Two hours at most.”

“No. I mean—how long until you can communicate with other dimensions?”

“Sweetheart, you know we can’t pinpoint these things,” my father says, but with a smile. “Of course, if next month’s test goes as well as we hope . . . wait and see.”

It’s all I can do not to laugh out loud.

As I walk back to my room, I’m already strategizing. I’m not going to “de-cloak” yet; first I should talk with my parents back home about everything we’ve learned. But as soon as I do that, we can start planning my return to this dimension. Then we can tell the truth, the whole honest truth, and get these versions of ourselves to join forces with us. Exhilaration bubbles inside me until I want to spin around and do some stupid victory dance. Once I’m alone in my room, I might.

However, when I look at my email, every other thought fades, replaced only by the sight of Paul’s name in my in-box.

When I open his reply, it says only 8:30 p.m.

He’s not exactly Mr. Talkative in my dimension either. This is all the information I asked for, the only thing I need.

Still, when I remember Mom’s distrust of Paul, her fear for me, Paul’s terseness becomes . . . unnerving.

But it won’t stop me from going to him, and bringing my own Paul home.

Cambridge must be a relatively safe place, because when I tell them I want to go to the theoretical late show of whatever movie it was this world’s Marguerite wanted to see on campus, Mom doesn’t even look up from her reading as she nods. Dad says only, “Wouldn’t you rather take the car?”

Of course he lets me drive only in a universe where I’d have to stay on the left side of the road. “I’m good.”

“I’m glad you’re exploring your interest in film,” he says. “Definitely something to pursue.”

Mom chimes in, suddenly much more interested. “So many people talented in one art form prove to be talented in another.”

Maybe this world’s Marguerite is thinking of becoming a movie director. I can’t quite imagine it, but that’s kind of cool.

As I cycle through the streets of Cambridge, my phone chirpily tells me where to turn and how far to go. Not all of the city is as picturesque as the university; I cross a few busy roads lined with buildings more blandly modern. The chain store signs lit for nighttime bear unfamiliar names: BOOTS, COSTA, PIZZA EXPRESS. But my directions keep me near the university and finally steer me toward a group of small, basic apartments immediately recognizable as the kind of place where students live.

I lock my bike, walk straight to Paul’s door, and ring without hesitating.

Before my hand is back at my side, Paul opens the door.

He looks thinner in this dimension, and not in a good way; his clothes are the same shabby stuff he wears at home, but they hang on his frame, like he doesn’t even care enough to get stuff that fits. Still, he’s neat, and from the faint smell of shaving foam, I can tell Paul cleaned up for me. He’s trying.

“Hi,” he says. “Thanks for reaching out. It—it means a lot.”

“Can I come in?”

Paul seems astonished. Did he really think I’d stand here and question him from the doorstep?

But he stands back for me to walk into his apartment. It’s as small and plain as I would have thought, with worn, mismatched furniture bought at the Salvation Army or whatever the British equivalent is. Tidy, though—especially for a male college student. My Paul keeps things neater than virtually any other guy I’ve ever known; I wonder if the white-glove cleanliness of this room is something this world’s Paul shares with mine, or whether it’s the subconscious influence of my own Paul peeking through.

I ought to just press the Firebird against him now, get my Paul back, and get out of here. But something about this Paul’s quiet misery touches me. He’s hurting—terribly—and he seems to think talking with me would help.

I can give him that. His body has kept the last part of Paul’s soul safe; we owe him.

Instead of hi or how have you been, Paul says, “Will you let me explain?” When I blink, surprised, he continues, “I guess that’s why you’re here. If it’s not—”