CONTENTS

  Chapter 1

  Chapter 2

  Chapter 3

  Chapter 4

  Chapter 5

  Chapter 6

  Chapter 7

  Chapter 8

  Chapter 9

  Chapter 10

  Chapter 11

  Chapter 12

  Chapter 13

  Chapter 14

  Chapter 15

  Chapter 16

  Chapter 17

  Chapter 18

  Chapter 19

  Chapter 20

  Chapter 21

  Chapter 22

  Chapter 23

  Chapter 24

  Chapter 25

  Chapter 26

  Chapter 27

  Acknowledgments

  Back Ads

  About the Author

  Books by Claudia Gray

  Credits

  Copyright

  About the Publisher

  1

  MY HAND SHAKES AS I BRACE MYSELF AGAINST THE BRICK wall. Rain falls cold and sharp against my skin, from a sky I’ve never seen before. It’s hard to catch my breath, to get any sense of where I am. All I know is that the Firebird worked. It hangs around my neck, still glowing with the heat of the journey.

  There’s no time. I don’t know whether I have minutes, or seconds, or even less. Desperately I tug at these unfamiliar clothes—the short dress and shiny jacket I wear have no pockets, but there’s a small bag dangling from my shoulder. When I fish inside, I can’t find a pen, but there’s a lipstick. Fingers trembling, I unscrew it and scrawl on a tattered poster on the wall of the alley. This is the message I must pass on, the one goal I have to remember after everything else I am is gone.

  KILL PAUL MARKOV.

  Then I can only wait to die.

  Die isn’t the right word. This body will continue to breathe. The heart will continue to beat. But I won’t be the Marguerite Caine living in it anymore.

  Instead, this body will return to its rightful owner, the Marguerite who actually belongs in this dimension. The dimension I leaped into, using the Firebird. Her memories will take over again, any second, any moment, and while I know I’ll awaken again in time, it’s terrifying to think about . . . passing out. Getting lost. Being trapped inside her. Whatever it is that happens to people traveling from another dimension.

  It hits me then. The Firebird really works. Travel between alternate dimensions is possible. I just proved it. Within my grief and fear, one small ember of pride glows, and it feels like the only heat or hope in the world. Mom’s theories are true. My parents’ work is vindicated. If only Dad could have known.

  Theo. He’s not here. It was unrealistic of me to hope he would be, but I hoped anyway.

  Please let Theo be all right, I think. It would be a prayer if I still believed in anything, but my faith in God died last night too.

  I lean against the brick wall, hands spread like a suspect’s on a police car right before the cuffs go on. My heart hammers in my chest. Nobody has ever done this before—which means nobody knows what’s about to happen to me. What if the Firebird can’t bring me back to my own dimension?

  What if this is how I die?

  This time yesterday, my dad probably asked himself that same question.

  I close my eyes tightly, and the cold rain on my face mingles with hot tears. Although I try not to picture how Dad died, the images force their way into my mind over and over: his car filling with water; brownish river lapping over the windshield; Dad probably dazed from the wreck but scrambling to get the door open, and failing. Gasping for the last inches of air in the car, thinking of me and Mom and Josie—

  He must have been so scared.

  Dizziness tilts the ground beneath my feet, weakens my limbs. This is it. I’m going under.

  So I force my eyes open to stare at the message again. That’s the first thing I want the other Marguerite to see. I want that message to stay with her, no matter what. If she sees that, if she keeps running over those words in her mind, that will awaken me within her as surely as the Firebird could. My hate is stronger than the dimensions, stronger than memory, stronger than time. My hate is now the truest part of who I am.

  The dizziness builds, and the world turns fuzzy and gray, blackening the words KILL PAUL MARKOV—

  —and then my vision clears. The word KILL sharpens back into focus.

  Confused, I step back from the brick wall. I feel wide awake. More so than before, actually.

  And as I stand there, staring down at my high heels in a puddle, I realize that I’m not going anywhere.

  Finally, as I begin to trust my luck, I step farther into the alley. The rain beats down harder on my face as I look up into the storm-drenched sky. A hovercraft looms low over the city like yet another thundercloud. Apparently it’s there to fly holographic billboards across the city skyline. Astonished, I gaze at the hovercraft as it soars through this strange new dimension, 3D advertisements flickering through their motions in the sky around it: Nokia. BMW. Coca-Cola.

  This is so like my world, and yet not my world at all.

  Is Theo as overwhelmed by the journey as I am? He must be. His grief is nearly as deep as mine, even though Dad was only his adviser; more than that, this is what Theo and my parents worked for these past few years. Has he kept his memory as well? If so, we’ll be in control throughout the trip, our minds piloting the selves born in this alternate dimension. That means Mom was wrong about one thing—which is kind of staggering, given that every other theory she’s ever had has just been proved true. But I’m grateful for it, at least for the moment before my gratitude disintegrates in the hot blaze of anger.

  Nothing can stop me now. If Theo made it too and he can find me—and I want so desperately for him to find me—then we’ll be able to do this. We can get to Paul. We can take back the Firebird prototype he stole. And we can take our revenge for what he did to my father.

  I don’t know if I’m the kind of person who can kill a man in cold blood. But I’m going to find out.

  2

  I’M NOT A PHYSICIST LIKE MOM. NOT EVEN A GRAD STUDENT in physics like Paul and Theo. I’m the homeschooled daughter of two scientists who gave me a lot of leeway to direct my own education. As the only right-brained member of the family, I wound up pursuing my passion for painting a whole lot more than I ever studied higher-level science. In the fall, I’m headed to the Rhode Island School of Design, where I’m going to major in art restoration. So if you want to mix oil paints, stretch a canvas, or discuss Kandinsky, I’m your girl. The science underlying cross-dimensional travel? No such luck. But here’s what I know:

  The universe is in fact a multiverse. Countless quantum realities exist, all layered within one another; we’ll call these dimensions, for short.

  Each dimension represents one set of possibilities. Essentially, everything that can happen does happen. There’s a dimension where the Nazis won World War II. A dimension where the Chinese colonized America long before Columbus ever sailed over. And a dimension where Brad Pitt and Jennifer Aniston are still married. Even a dimension just like my own, identical in every way, except on one day in fourth grade, that Marguerite chose to wear a blue shirt while I chose to wear a green one. Every possibility, every time fate flips a coin, splits the dimensions yet again, creating yet more layers of reality. It goes on and on forever, to infinity.

  These dimensions aren’t off in faraway outer space. They’re literally all around us, even within us, but because they exist in another reality, we can’t perceive them.

  Early in her career, my mom, Dr. Sophia Kovalenka, hypothesized that we should be able not only to detect those dimensions but also to observe them—even interact with them. Everyone
laughed. She wrote paper after paper, expanded her theory year after year, and nobody would listen.

  Then one day, just when it looked like she was going to get permanently written off as a crackpot, she managed to publish one more paper pointing out parallels between wave theory and her work on dimensional resonance. Possibly only one scientist on earth took that paper seriously—Dr. Henry Caine, an English oceanographer. And physicist. And mathematician. And, obviously, overachiever. When he saw the paper, he was able to grasp potential that nobody else had ever seen before in the theory. This was lucky for Mom, because once they became research partners, her work really started to go somewhere.

  This was even luckier for Josie and me, because Dr. Henry Caine would become our dad.

  Fast-forward twenty-four years. Their work had reached the point where it was starting to attract notice even outside scientific circles. The experiments in which they’d shown evidence of alternate dimensions had been replicated by other scientists at Stanford and Harvard; nobody was laughing at them anymore. They were ready to try traveling between dimensions—or, at least, to fashion a device that could make it possible.

  Mom’s theory is that it would be very, very difficult for physical objects to move between dimensions, but energy should be able to move fairly easily. She also says consciousness is a form of energy. This led to all kinds of crazy speculation—but mostly Mom and Dad remained focused on building a device that would turn dimensional travel into more than a dream. Something that would allow people to journey to another dimension at will, and, even trickier, to come back again the same way.

  This was daring. Even dangerous. The devices have to be made out of specific materials that move much more easily than other forms of matter; they have to anchor the consciousness of the traveler, which is apparently very difficult; and about a million other technical considerations I’d have to get umpteen physics degrees to even understand. Long story short: the devices are really hard to make. Which is why my parents went through several prototypes before even considering a test.

  So when they finally had one that seemed like it would work, only a couple of weeks ago, we had to celebrate. Mom and Dad, who usually drink nothing stronger than Darjeeling, opened a bottle of champagne. Theo handed me a glass too, and nobody even cared.

  “To the Firebird,” Theo said. The final prototype lay on the table around which we stood, its workings gleaming, intricate layers of metal folded in and atop each other like an insect’s wings. “Named after the legendary Russian creature that sends heroes on amazing quests and adventures”—here Theo nodded at my mother, before continuing—“and of course after my own muscle car, because yes, it’s just that cool.” Theo is a guy who says things like “muscle car” ironically. He says almost everything ironically. But there was real admiration in his eyes as he looked at my parents that night. “Here’s hoping we have some adventures of our own.”

  “To the Firebird,” Paul said. He must have been plotting what he was going to do right then, even as he lifted his glass and clinked it against Dad’s.

  Basically, after decades of struggle and ridicule, my parents had finally reached the point where they’d gained real respect—and they were on the brink of a breakthrough that would take them far beyond that. Mom would’ve been heralded as one of the leading scientists in all history. Dad would have gotten at least Pierre Curie status. We could maybe even have afforded for me to take a summer art tour in Europe, where I could go to the Hermitage and the Prado and every other amazing gallery I’d heard of but never seen before. Everything we’d ever dreamed of was on the horizon.

  Then their trusted research assistant, Paul Markov, stole the prototype, killed my father, and ran.

  He could have gotten away with it, slipping into another dimension beyond the reach of the law: the perfect crime. He vanished from his dorm room without a trace, leaving his door locked from the inside.

  (Apparently when people travel between dimensions, their physical forms are “no longer observable,” which is a quantum mechanics thing, and explaining it involves this whole story about a cat that’s in a box and is simultaneously alive and dead until you open the box, and it gets seriously complicated. Never ask a physicist about that cat.)

  Nobody could find Paul; nobody could catch him. But Paul didn’t count on Theo.

  Theo came to me earlier this evening as I sat on the rickety old deck in our backyard. The only illumination came from the full moon overhead and the lights Josie had strung on the railing last summer, the ones shaped like tropical fish that glowed aquamarine and orange. I had on one of Dad’s old cardigans over my ivory lace dress. Even in California, December nights can be cold, and besides—the sweater still smelled like Dad.

  I think Theo had watched me for a while before he came out there, waiting for me to pull myself together. My cheeks were flushed and tear streaked. I’d blown my nose so many times that it felt raw every time I inhaled. My head throbbed. But for the moment, I’d cried myself out.

  Theo sat on the steps beside me, jittery, on edge, one foot bouncing up and down. “Listen,” he said. “I’m about to do something stupid.”

  “What?”

  His dark eyes met mine, so intent that I thought, for one crazy moment, despite everything that was going on, he was about to kiss me.

  Instead, he held out his hand. In it were the two other versions of the Firebird. “I’m going after Paul.”

  “You—” My wavering voice, already strained from crying, broke. I had so many questions that I couldn’t even begin at first. “You still have the old prototypes? I thought you broke them down afterward.”

  “That’s what Paul thought too. And—well, technically, always what your parents thought.” He hesitated. Even mentioning Dad, only a day after his death, hurt so terribly—for Theo nearly as much as for me. “But I kept the parts we didn’t reuse. Tinkered with them, borrowed some equipment from the Triad labs. Used the advances we made on the last Firebird to improve these two. There’s a decent shot one of these will work.”

  A decent shot. Theo was about to take an incredible risk because it gave him a “decent shot” at avenging what Paul had done.

  As funny as he’d always been, as flirty as we occasionally got, I’d sometimes wondered whether Theo Beck was full of crap underneath his indie band T-shirts and his hipster hat and the 1981 Pontiac he’d fixed up himself. Now I was ashamed to have ever doubted him.

  “When people travel through dimensions,” he said, staring down at the prototypes, “they leave traces. Subatomic—okay, I’m gonna cut to the chase. The point is, I can go after Paul. No matter how often he jumps, how many dimensions he tries to move through, he’ll always leave a trace. And I know how to set these to follow that trace. Paul can run, but he can’t hide.”

  The Firebirds glinted in his palm. They looked like odd, asymmetrical bronze lockets—maybe jewelry fashioned in the era of Art Nouveau, when organic shapes were all the rage. One of the metals inside was rare enough that it could only be mined in a single valley in the whole world, but anyone who didn’t know better would just think they were pretty. Instead the Firebirds were the keys to unlock the universe. No—the universes.

  “Can you follow him anywhere?”

  “Almost anywhere,” Theo answered, and he gave me a look. “You know the limits, right? You didn’t tune out every time we talked about this around the dinner table?”

  “I know the limits,” I said, stung. “I meant, within those.”

  “Then yeah.”

  Living beings can only travel to dimensions where they already exist. A dimension where my parents never met? That’s a dimension I can never see. A dimension where I’m already dead? Can’t get there from here. Because when a person travels to another dimension, they actually materialize within their other self. Wherever that other version of you might be, whatever they’re doing: that’s where you are.

  “What if Paul jumps somewhere you can’t follow?” I asked.

&nbs
p; Theo shrugged. “I’ll end up in the next universe over, I guess. But it’s no big. When he jumps again, I’ll have a chance to pick up his trace from there.” His gaze was far away as he turned the Firebirds over in his palm.

  To me it sounded like Paul’s best bet would be to keep jumping, as fast as he could, until he found a universe where none of the rest of us existed. Then he could remain there as long as he liked, without ever getting caught.

  But the thing was, Paul wanted something besides destroying my parents. No matter what a creep he’d turned out to be, he wasn’t stupid. So I knew he wouldn’t do this out of sheer cruelty. If he’d just wanted money, he would have sold the device to somebody in his own dimension, not fled into another one.

  Whatever he wanted, he couldn’t hide forever. Sooner or later, Paul would have to go after his true, secret goal. When he did, that was when we could catch him.

  We could catch him. Not Theo alone—both of us. Theo held two prototypes in his hand.

  The cool breeze ruffled my hair and made the lights flutter back and forth on the deck railing, like the plastic fish were trying to swim away. I said, “What happens if the Firebird doesn’t actually work?”

  He scraped his Doc Martens against the old wood of the deck; a bit of it splintered away. “Well, it might not do anything. I might just stand there feeling stupid.”

  “That’s the worst-case scenario?”

  “No, the worst-case scenario involves me getting blended into so much atomic soup.”

  “Theo—”

  “Won’t happen,” he said, cocky as ever. “At least, I strongly doubt it.”

  My voice was hardly more than a whisper. “But you’d take that risk. For Dad’s sake.”

  Our eyes met as Theo said, “For all of you.”

  I could hardly breathe.

  But he glanced away after only a second, adding, “Like I said, it won’t happen. Probably either of these would work. I mean, I rebuilt them, and as we both know, I’m brilliant.”

  “When you guys were talking about testing one of these, you said there was no way in hell any of you should even consider it.”