Of that world’s Lieutenant Markov, who loved me so deeply, even when he knew I’d played him for a fool.

I don’t dare return to that dimension, which means I’ll never see any of those people again. But they deserve to lead their own lives and find their own fates. To have their chance to win the war, and survive.

And as much as it would hurt to learn that any of those people in the Warverse were dead, it would be infinitely worse to know that they had never been.

“You don’t even understand what you’re asking me to do.” My voice shakes. “Destroying a dimension—that would be worse than genocide.” They want me to destroy entire species, planets, stars, countless galaxies.

“Perhaps destroy is the wrong word,” Dad says, like a change in vocabulary would fix this. “Think of it as ‘unmaking’ the dimensions, and that’s really much closer to the mark.”

They’re so far gone they can’t even see it. I strike out with the first thing that comes to mind. “Josie would never accept this. Even if you succeeded, and you put her back together again, she would hate you for what you’d done.”

“I feel sure Josephine will see reason,” my father says, with the same tone of voice he used when he and Mom didn’t let Josie get her ears pierced a third time.

My mother adds, “Keep in mind that Josephine traveled far longer than you have. She’s seen how many versions there are of us, in all the worlds. One version more or less in the multiverse makes very little difference, mathematically speaking.”

“This is bigger than math! You can’t just swap one of us out for another!”

Mom seems almost irritated by my lack of comprehension. “All versions of us are the same person, on a very important level. Haven’t you seen that yet? Your Paul Markov—isn’t he the same one you love in every world, everywhere?”

Once I would have said yes. Now I know the truth is more complicated. As much as each version has in common with all the others, we’re still unique. Every single one of us, everywhere, is irreplaceable.

“Your universe is safe,” Mom says. That shouldn’t make me feel better on any level, but it does. I’m coward enough to be glad we’re not first on the chopping block. “Perfect travelers are a scarce resource. We can’t go unmaking them right and left.”

“You can see now why we need to keep the technology under wraps,” Dad chimes in. “If every dimension had this power, can you imagine the warfare that would result?”

I shake my head. “But if you’re the only dimension with this power, it’s not a war. It’s just a slaughter.”

“You make it sound so diabolical,” Dad says, as if it isn’t.

“Please, sweetheart, think this over after you’ve had a chance to calm down.” My mother is openly pleading with me, in a way she never has before. Despite everything, she’s enough like my real mom that seeing her this way makes my heart hurt. “We want to work with you. We want to make this the best it can be for everyone involved. And we can give you so much.”

“Like what?” The technology to turn our dimension into a hideous collage of Goya and Warhol, like theirs? That’s supposed to make up for turning me into a mass murderer?

She pauses; her eyes meet my dad’s. So Mom isn’t looking directly at me when she says, “We want to protect you, Marguerite. You’re our daughter too. But—if it came to it—Conley could travel to a new dimension and create another perfect traveler there.”

I know what she means the instant she says it. But it’s like my brain refuses that knowledge. Instead, I flush hot all over, and my stomach cramps, as if I drank poison that has to get out of me now, because if it stays inside it will destroy me.

My parents would kill my universe. They would kill me. All because one version is as good as another, because they think we’re all fungible, replaceable, disposable—

“You know that wouldn’t be easy for us,” Dad says, straightening. “We didn’t bring you to this dimension on a whim. You needed to learn the truth, though we’d hoped to break it to you more gently than this.”

I spit my reply back at him. “There’s no ‘gentle’ way to tell me to kill billions of people.”

He continues as if I hadn’t spoken. “Take your time. Think things over. Discuss it with us back at home! When you fully comprehend the difference between death and nonexistence—that none of those people would suffer the way Josephine suffered—”

Dad’s voice chokes on a sob. My mother grabs his hand as he closes his eyes tightly. Somehow this is the worst of all—seeing that they’re still my parents, still capable of love and compassion, and yet willing to order the death of worlds.

“I’m leaving,” I say, backing toward the door. “Don’t come after me.”

By this I mean, don’t follow me to the hallway, and definitely don’t follow me to my own world. But they don’t chase me. Mom and Dad simply stand there, looking sadder than I’ve ever seen them look in their lives.

They’re not only feeling sorry for themselves, though, or for the daughter who died. Mostly they feel sorry for me.

I could jump out of this universe where I stand; instead, I go out the door. That way I can slam it behind me and create the illusion that they can’t chase me, that I can leave everything I’ve learned here behind.

But they can follow me anywhere, and they will, until they get what they want. Or else they’ll destroy my entire world.

27

WITH SHAKING HANDS, I SET THE COORDINATES MY PARENTS gave me—the ones that are supposed to lead to the final splinter of my Paul’s soul. I close my eyes, press down—

—and slam into myself just in time to wobble out of control.

I’m riding a bike, I think, in the split second before I crash into a ditch.

Groaning, I scoot out from under my bicycle to see my knee red and raw, tiny droplets of blood beginning to bead up. Someone walking nearby says, in an English accent, “You all right, love?”

Honestly, at the moment, it’s almost a relief to have my biggest problem be a skinned knee. “I’m fine, thank you.”

That came out with an English accent too. Do I live in London in this world as well? Seems really green for that . . .

I look up and recognize where I am right away. Most people wouldn’t, but most people didn’t grow up surrounded by graduate students, who often carried brochures from the best physics departments in the world while they tried to figure out where to do their postdoc work.

When I see the Bridge of Sighs, I know I’m in Cambridge.

This makes sense. Both my mother and my father could easily have wound up teaching here; in this world, they did. Now I have to figure out what else has changed.

My first task on leaping into a new dimension is always to understand the essentials as best I can: where I am, who I am. In this case, I desperately want to find Paul right away. I need him more than I ever have before. But for a moment I can only sit there in the grass, shaking, thinking of the lunatic versions of my parents I just left behind and what they want from me.

Green trees. The beautiful old university. Faraway sounds of traffic. Students laughing as they run across the grass. Triad might destroy this universe too.