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