“How?”

“Well, first, we have to find out exactly how much corridor time this drug will give us. Down to the minute.”

“How far do you want to wind out the clock?”

“If you’re saying we have about an hour, then our deadline is ninety minutes on your watch. That accounts for thirty minutes for the drug to kick in, plus the sixty minutes we’re under its influence.”

“I weigh less than you. What if it affects me for longer?”

“It doesn’t matter. The moment it stops working on one of us, that person will decohere the quantum state and collapse the corridor. Just to be safe, let’s start opening doors at the eighty-five-minute mark.”

“And hope for what exactly?”

“A world that doesn’t eat us alive.”

She stops and looks at me. “I know you didn’t actually build this box, but you must have some idea of how all this works.”

“Look, this is light-years beyond anything I could’ve—”

“So is that a ‘No, I don’t have any idea’?”

“What are you asking me, Amanda?”

“Are we lost?”

“We’re gathering information. We’re working a problem.”

“But the problem is that we’re lost. Right?”

“We’re exploring.”

“Jesus Christ.”

“What?”

“I don’t want to spend the rest of my life wandering down this never-ending tunnel.”

“I won’t let that happen.”

“How?”

“I don’t know yet.”

“But you’re working on it?”

“Yes. I’m working on it.”

“And we’re not lost.”

We are so fucking lost. Literally adrift in the nothing space between universes.

“We’re not lost.”

“Good.” She smiles. “Then I’ll postpone freaking out.”

—

We move along in silence for a while.

The metal walls are smooth and featureless, nothing to distinguish one from the next and the next and the next.

Amanda asks, “What worlds do you think we actually have access to?”

“I’ve been trying to puzzle that out. Let’s assume the multiverse began with a single event—the Big Bang. That’s the starting point, the base of the trunk of the most immense, elaborate tree you could fathom. As time unfolded and matter began to organize into stars and planets in all possible permutations, this tree sprouted branches, and those branches sprouted branches, and on and on, until somewhere, fourteen billion years down the line, my birth triggered a new branch. And from that moment, every choice I made or didn’t make, and the actions of others that affected me—those all gave rise to more branches, to an infinite number of Jason Dessens living in parallel worlds, some very similar to the one I call home, some mind-bogglingly different.

“Everything that can happen will happen. Everything. I mean, somewhere along this corridor, there’s a version of you and me that never made it into the box when you tried to help me escape. And now we’re being tortured or already dead.”

“Thanks for the morale boost.”

“Could be worse. I don’t think we have access to the entire breadth of the multiverse. I mean, if there’s a world where the sun burned out just as prokaryotes—the first life-forms—were appearing on Earth, I don’t think any of these doors open into that world.”

“So we can only walk into worlds that…”

“If I had to guess, worlds that are adjacent to ours somehow. Worlds that split off at some point in the recent past, which are next door to ours. That we exist in, or existed in at some point. How far back they branched, I don’t know, but my suspicion is there’s some form of conditional selection at work. This is just my working hypothesis.”

“But we’re still talking about an infinite number of worlds, right?”

“Well, yeah.”

I lift her wrist and press the light feature on her watch.

The tiny square of luminous green shows…

84:50.

84:51.

I say, “The drug should wear off in the next five minutes. I guess it’s time.”

I move toward the next door, hand Amanda the lantern, and grip the handle.

Turning the lever, I pull the door open one inch.

I see a concrete floor.

Two inches.

A familiar glass window straight ahead.

Three.

Amanda says, “It’s the hangar.”

“What do you want to do?”

She pushes past me and steps out of the box.

I follow, the lights shining down on us.

Mission control is empty.

The hangar quiet.

We stop at the corner of the box and peer around the edge toward the vault doors.

I say, “This isn’t safe.” My words carry through the expanse of the hangar like whispers in a cathedral.

“And the box is?”

With a thunderous clang, the vault doors disengage and begin to part.

Panicked voices bleeding through the opening.

I say, “Let’s go. Right now.”

A woman is fighting to squeeze through the space between the doors.

Amanda says, “Oh my God.”

The vault doors are only fifty feet away, and I know we should go back into the box, but I can’t stop watching.

The woman pushes through the doors into the hangar, and then reaches back and gives a hand to the man behind her.

The woman is Amanda.

The man’s face is so swollen and battered I wouldn’t have known right away that he was me except he’s wearing clothes identical to mine.

As they begin running toward us, I start to involuntarily retreat to the door of the box.

But they only make it ten feet before Leighton’s men rush through the doors behind them.

A gunshot stops Jason and Amanda in their tracks.

My Amanda starts toward them, but I pull her back.

“We have to help them,” she whispers.

“We can’t.”

Peeking around the corner of the box, we watch our doppelgängers turn slowly to face Leighton’s men.

We should leave.

I know this.

Part of me is screaming to go.

But I can’t tear myself away.

My first thought is that we’ve gone back in time, but of course that’s impossible. There’s no time travel in the box. This is simply a world where Amanda and I escaped several hours later.