By follow, I mean possess.

I had just leaped back into my own body after a mad chase to save Paul Markov, who is—

—what can I call him? Throughout the multiverse, our fates are entwined in ways both beautiful and tragic. We have seen worlds where we rejected each other, hurt each other, hated each other—and the knowledge of how terrible our romance could turn devastated us both.

But I’ve got bigger problems than my love life.

The moment I returned to my own dimension, I opened my eyes to see Theo standing above me. He looked haggard and pale—proof of the terrible damage done to him by the drug Nightthief, the one that made it possible for another dimension’s Theo to possess him and spy on us for months. Paul had endangered himself to find a cure and save our friend’s life. “About time you got here,” Theo said with a wry smile.

“Good, you made it. How do you feel?”

“I’ve been better.” His faux-vintage Beatles T-shirt hung on his too-skinny frame. Dark circles shadowed his eyes. So his first question seemed natural. “But, hey, you got the juice, right? The data for the juice, I mean.” He meant the treatment for exposure to Nightthief.

“Right. You’ll be feeling better in no time.” I looked around for my parents, who needed to hear about Triad’s plans ASAP. We had believed only one other dimension was spying on us, trying to manipulate events, but I’d found out that the real threat was a third dimension, the powerful Home Office, which had plans so much darker than mere spying. “Where are Mom and Dad?”

“They were out when I got here. Probably at the university labs, trying to figure some other way out of this, or building another Firebird.”

I nodded absently. No point in calling them—my mom and dad, the illustrious scientists who created the most miraculous device in existence, rarely remembered to turn their cell phones on because that’s too much technology. But they weren’t the only ones I worried about. “Have you checked to see if Paul has come back yet?”

“You found him, huh?”

As I sat up, dizziness overtook me—nausea and vertigo both.

That was the sign. The warning. The moment I should’ve protected myself.

Instead, I only thought I’d moved too quickly. “Whoa. What was that?”

“You’ve been through a lot,” Theo said. In the moment I didn’t recognize the gleam of triumph in his eyes. “No wonder you’re tired.”

Still I felt strange. Uneasy. But I didn’t suspect what was coming.

“So, Paul was going to come back at the exact same time as you?” Theo asked.

“That’s what he said. Where did I leave my phone? I want to call him.”

 

“Don’t worry,” Theo began going through the constant mess of papers on the rainbow table; I thought he was looking for my tPhone. “Take it easy. You’ll find him, Meg.”

Meg.

Only one person ever called me that. Theo—but not my Theo.

Only the spy from the Triadverse.

I turned to him in horror, realizing he would attack, but it was already too late. Theo and I scrabbled and fought until he pinned me on the wooden floor and injected me with a syringe filled with emerald-green liquid—Nightthief.

At first I thought he was a fool. Nightthief helps interdimensional travelers take over their hosts and retain full consciousness and control. But I was home in my own body. Was he trying to poison me? Nightthief took months to kill—

—I shuddered, and then I couldn’t move. Not my head, not my hand. Yet my lungs breathed without me, and my voice spoke someone else’s words: “About time.”

Theo smiled as he rose to let me up. “Always a pleasure to meet anyone from the Home Office.”

I would’ve screamed if I could. The three dimensions in which Triad existed were my own; the Triadverse, a world very close to my own but only a few years ahead in technology; and the Home Office, a futuristic hellscape where ruthlessness ruled and profit was God.

During my adventures in different dimensions, I’ve lived within many of my other selves and learned who I would be if history had unfolded just a bit differently. I could dwell in a Russian palace or under the sea. Sometimes other versions of me made choices I didn’t understand; sometimes they dealt with depression and solitude. But none of them had horrified me more than my Home Office version.

She did Triad’s bidding. She wouldn’t hesitate to kill. She loved to cause pain, which she called her art.

And she had hijacked my body, leaving me powerless.

She seemed to be in charge, too, because Theo asked her, “So, what’s our first assignment?”

“Figure out what they’re up to.” She smiled. Feeling her smile, knowing that she enjoyed turning my body into a prison of flesh and bone—it revolted me more than anything else ever had. “My parents aren’t the kind of people to surrender even if it’s the smart thing to do, in any universe. But once the versions here have been outsmarted a few times, sabotaged a few times more . . . well, we might be able to bring them in line yet.”

Theo nodded and helped her to her feet. “And if we don’t get them to work for our cause?”

She laughed. “Then it’s time for this dimension to die.”

The Firebird only allows you to visit universes in which you exist, because your consciousness can only leap into another version of yourself. I prided myself on taking good care of the other Marguerites, on getting them out of any danger I got them into. But then I caused some problems I couldn’t solve. One version of Theo may never walk again because of me. Another Marguerite has been caught up in a multidimensional conspiracy she should never have had to be part of.

And a second me—one I inhabited for nearly a month, one in which I realized I was in love with Paul Markov and went to bed with him—is now expecting the baby I conceived for her.

So I’d come back to my own dimension humbled. Ashamed. Determined. There had to be more ethical ways of traveling through the worlds, ways that wouldn’t endanger or violate our other selves.

But I had no idea how profound the violation was until another Marguerite leaped into me.

“Look at this mess,” sneered the other Marguerite in my body, the one I’d already begun to think of as the Wicked Marguerite. She shoved a stack of papers covered with scribbled formulae, and they fluttered to the Turkish rug on the floor. As she glanced around the room through my eyes, at the books and the potted plants, the blackboard-paint wall with its chalk equations, and the rainbow table Josie and I hand-painted as children, she didn’t see home. Instead, my lips curled in contempt. “Primitive. Disorganized. They might as well live in a cave.”