Dr. Brier was dressed completely in black. Black pantsuit, black heels. In the stark spotlight, her head looked almost disconnected from her body, and her hands fluttered like flying birds as she gesticulated to the crowd. Her highlighted hair swirled as she walked from one side of the stage to the other. I could see the reflecting glint of her golden eyes like two faraway jewels. Her voice, through the microphone, had a mellifluous quality, the kind of singsong sweetness that could hypnotize you or seduce you, depending on what she wanted. It worked its magic. I didn’t think I’d ever heard our ballroom as drop-dead quiet as it was at that moment. Dr. Brier had these hundreds of people holding their breath.

“Think about what this means,” she told them, drawing out her words with a pregnant pause. “If we accept the Many Worlds theory as true, then our universe is constantly replicating itself, atom by atom, moment by moment, choice by choice. Every possible outcome of an event exists in its own separate world. We are all inching along on a single, solitary, fragile branch of a tree that grows infinitely larger with each nanosecond. As I leave the ballroom tonight, I turn left, but I also turn right. I go home, and I don’t go home. I kiss my husband, and I slap his face, and I have sex with him, and I stick a knife in his heart. In my consciousness, I only experience one of those outcomes, because I’m on one branch of the tree. But the Many Worlds theory tells us that all of those things happen in parallel universes.”

She paused. “Of course, I’m sure my husband is hoping I’m in bed with him later and not wiping the blood off my knife.”

Laughter rippled through the crowd.

“In fact, I’m not actually married,” she said, “not in this life. However, in a myriad of other worlds, I am. In other worlds, I’m not a psychiatrist, I’m an actor, I’m a cop, I’m a homeless drug addict. In other worlds, I’m not alive; I’m dead. And so are you. There are infinite copies of you in infinite worlds, making all of the choices you don’t make in this life. That’s what the theory says.”

Dr. Brier stopped in the middle of the stage.

“Is this crazy talk? The ravings of mad scientists trying desperately to explain why their elegant math doesn’t work in the real world? Well, maybe. Or maybe our vision of the universe is simply limited by what we can see. Until we had microscopes and could look at a drop of blood, nobody would have believed that there were so many other worlds living inside it. Millions of cells inside a single drop of blood! Impossible! But now we know it to be true. So is the idea of the Many Worlds an absurd theory? Or do we just need a better microscope?”

There was something magnetic about this woman. She wasn’t speaking to the audience as a whole. She was speaking to everyone in the room. Personally. Individually. Or maybe she was just talking to me, because that was how it felt. Standing on the balcony, I might as well have been alone with her in the giant ballroom. I felt her watching me. Staring up at me. Directing all her comments and thoughts to me. I expected her to use my name.

Dylan, you are not alone. You are part of many worlds.

You are infinite.

“Philosophers took this idea from the physicists and came up with their own theory,” Dr. Brier continued. “They called it the Many Minds. Their theory is that all these endless choices, all these parallel lives, really do exist—not in the big wide universe, but inside our individual brains. We’re the ones who divide like amoebas over and over. Still sound crazy? Well, think about your dreams. A dream is an elaborate world that your brain creates instantaneously. All that extraordinary detail devoted to building a fantasy place that only exists for a few moments of sleep, never to be visited again. If the brain can do that night after night after night, then maybe it isn’t so strange to think that it can build entire parallel worlds, too. No, for me, the important question isn’t whether it’s possible. The question is, What does this have to do with you and me and our actual lives? With our single little branch of the tree? Does any of this really matter if it’s all just theoretical? Because physicists and philosophers don’t agree on much, but they do agree on one thing. Whether it’s Many Worlds or Many Minds, we’re stuck on our own branch. Isolated. Powerless. Every version of yourself lives in its own separate world, and you can’t visit those other universes.”

Dr. Brier let all of that sink in. She took a sip of water from a bottle on the stool placed in the middle of the stage. Before she began to speak, I saw it again. Her eyes shifted to the balcony.

She stared directly at me.

“Or can you?”

After her speech was over, I waited in a long line to meet her. This whole event was about selling books. She’d written a self-help book, using the hook of the Many Worlds, Many Minds theories to give it a sexy twist. The idea was to teach people to lead better lives by showing them how to “visit” the alternate choices they’d made in parallel worlds.

Still wondering if you should have asked your college girlfriend to marry you? Imagine the version of yourself that’s living in that world.

Trying to decide whether to take that new job? Somewhere in the universe, you will. What does that life look like?

I understood the appeal of the theory. I was drawn to the idea that there was a universe right now where I hadn’t driven into that river. Somewhere, either in another world or buried inside my head, Karly was still alive, and I was still with her.

Believe me, I would have done anything to have that life for myself.

But that was a different Dylan. A Dylan who made better choices.

I could see Dr. Brier on stage as the guests trooped across one at a time to get her signature, along with a smile and a photo. She was attractive, eloquent, and persuasive, the way all cult leaders tend to be. I kept staring at her face and trying to remember where I could have met her, but I came up blank. It had to be a mistake. Somehow, Tai had misunderstood what she said.

Finally, it was my turn. I walked across the stage, leaving the line of people behind me. I had the copy of the book I’d bought in my hand. Dr. Brier’s eyes watched me come closer. I reached the table where she was seated by herself, and I could feel myself enveloped by her aura. I stood over her and handed her the book to sign. She took it, but her smile looked forced.

“Hello, Dylan,” she murmured. “I saw you in the balcony. I didn’t think you’d come. It’s not such a good idea, you and me being seen together.”

Her words threw me off balance. “I’m sorry, do you know me?”

She froze before she signed the book. Her almond-shaped brown eyes bored into mine. “Is that a joke?”

“No.”

“I don’t like this game, Dylan.”

“I’m sorry, Dr. Brier, but you must have me confused with someone else. As far as I know, we’ve never met.”

“I see.” She glanced at the people still in line on the other side of the stage, and then she swept her long hair across her head. She signed the book with a flourish, added a little note, and then handed it back to me across the table. As she did, her fingertips grazed mine.

“My mistake,” she said. “Enjoy the book.”

I walked away in a daze. I glanced over my shoulder to see if she was watching me, but she’d moved on to the next person. I left the ballroom and found a bench near the elevators, where I sat down and opened the book.

Below her signature, she’d added a note.

The fountain. 1:00 a.m.

CHAPTER 7

Three hours later, I walked into Grant Park with a cold lake wind blowing into my face. I kept my hands in my pockets and my head down. Every few steps, I looked back at the lights of Michigan Avenue to see if I was being followed. I didn’t feel his presence now—my presence—but that didn’t mean my doppelg?nger wasn’t here.

I crossed over the railroad tracks and continued beside the green lawns of the park. Traffic was light, and I jogged to the other side of Columbus to get to the Buckingham Fountain. Its water cannons had been stilled until morning. Beyond the fountain, the dark swath of Lake Michigan filled the horizon. I stood by the pond for a while, near the sculptures of the seahorses, and then I found a bench on the south side of the plaza to wait.

I wasn’t alone. I saw a homeless man wrapped in a blanket on one of the benches near me. From behind me, I heard the sultry breaths of a couple having sex in the shelter of the trees. Near the fountain, two silhouettes whispered to each other, and I saw something pass from one hand to another. Drugs.

Dr. Eve Brier arrived exactly on time. I checked my watch, and it was one in the morning on the dot. I saw her coming, still in black, with a dark trench coat waving like a cape behind her as the wind blew. I stood up as she approached, and she came up and put her arms around me, an oddly intimate gesture that took me aback. Her perfume rose off her skin like a bouquet of roses. To anyone watching us, we must have looked like two lovers meeting, but I felt her hands exploring my back and then my chest, patting me down.

“What are you doing?” I asked her.

“Making sure you’re not wearing a wire.”

“Why on earth would I do that?”

“I don’t know, Dylan, but none of this makes sense. I’d rather be careful.”

We sat down next to each other on the bench. I could feel an incredible tenseness radiating from her. She was scared of something. Her head swiveled, surveying the shadows to see if we were being watched.

“What was all that about in the ballroom?” she asked me.

“What do you mean?”

“Pretending not to know me.”