The water bottles are calling out to me. I haven’t had anything to drink in hours, since lunch. My thirst is blaring.

I open the leather bag. It looks custom-made for the ampoules, each glass vial held in its own miniature sleeve.

I begin to count them.

“Fifty,” Amanda says. “Well, forty-eight now. I would’ve grabbed two backpacks, but…”

“You weren’t planning to come with me.”

“How fucked are we?” she asks. “Be honest.”

“I don’t know. But this is our spaceship. We’d better learn to fly it.”

As I begin to cram everything back into the pack, Amanda reaches for the injection kits.

This time, we break the necks of the ampoules and drink the drug, the liquid sliding across my tongue with a sweet, borderline unpleasant sting.

Forty-six ampoules remaining.

I start the timer on Amanda’s watch and ask, “How many times can we take this stuff and not fry our brains?”

“We did some testing a while back.”

“Pulled some homeless guy off the street?”

She almost smiles. “Nobody died. We learned that repeated use definitely strains neurological functioning and builds up a tolerance. The good news is the half-life is really short, so as long as we’re not slamming one ampoule right after another, we should be all right.” She slides her feet back into her flats, looks at me. “Are you impressed with yourself?”

“What do you mean?”

“You built this thing.”

“Yeah, but I still don’t know how. I understand the theory, but creating a stable quantum state for human beings is…”

“An impossible breakthrough?”

Of course. The hair on the back of my neck stands up as the improbability of it all makes sense.

I say, “It’s a one in a billion chance, but we’re dealing with the multiverse. With infinity. Maybe there are a million worlds like yours, where I never figured it out. But all it takes is one where I did.”

At the thirty-minute mark, I note the first sensation of the drug taking effect—the flickering of a shining, bright euphoria.

A beautiful disengagement.

Though not quite as intense as in the Velocity Laboratories box.

I look at Amanda.

I say, “I think I feel it.”

She says, “Me too.”

And we’re back in the corridor.

I ask, “Is your watch still running?”

Amanda tugs back the sleeve of her sweater and illuminates the watch face into tritium green.

31:15.

31:16.

31:17.

I say, “So a little over thirty-one minutes since we took the drug. Do you know how long it’s supposed to alter our brain chemistry?”

“I’ve heard about an hour.”

“Let’s clock it to be sure.”

I move back toward the door to the parking garage and pull it open.

Now I’m staring into a forest.

Except there’s no trace of green.

No trace of life.

Just scorched trunks as far as I can see.

The trees look haunted, their spindly branches like black spiderwebs against a charcoal sky.

I close the door.

It automatically locks.

Vertigo hits me as I watch the box push out away from me again, smearing off into infinity.

I unlock the door, drag it back open.

The corridor collapses again.

The dead forest is still there.

I say, “Okay, so now we know that the connections between the doors and these worlds only hold during a given session on the drug. That’s why none of your pilots ever made it back to the lab.”

“So when the drug kicks in, the corridor resets?”

“I think so.”

“Then how do we ever find our way home?”

—

Amanda begins to walk.

Faster and faster.

Until she’s jogging.

Then running.

Into a darkness that never changes.

Never ends.

The backstage of the multiverse.

The exertion is making me sweat and ratcheting my thirst to an unbearable level, but I say nothing, thinking maybe she needs this. Needs to burn through some energy. Needs to see that no matter how far she goes, this corridor will never end.

I suppose we’re both just trying to come to terms with how horrifying infinity really is.

—

Eventually, she burns out.

Slows down.

There’s nothing but the sound of our footfalls echoing into the darkness ahead of us.

I’m light-headed with hunger and thirst, and I can’t stop thinking about those two liters of water in our backpack, wanting them, but knowing we should save them.

Now we move methodically down the corridor.

I hold the lantern so I can inspect every wall of every box.

I don’t know what I’m looking for exactly.

A break in the uniformity, perhaps.

Anything that might let us exert some measure of control over where we end up.

All the while, my thoughts race in the dark—

What will happen when the water’s gone?

When the food is gone?

When the batteries that power this lantern—our only source of light—fail?

How will I ever find my way home?

I wonder how many hours have passed since we first entered the box back at the Velocity Laboratories hangar.

I’ve lost all sense of time.

I’m faltering.

Exhaustion bears down so hard on me that sleep seems sexier than water.

I glance over at Amanda, her features cold but beautiful in the blue light.

She looks terrified.

“Hungry yet?” she asks.

“Getting there.”

“I’m really thirsty, but we should save the water, right?”

“I think that’s the smart thing to do.”

She says, “I feel so disoriented, and it’s getting worse by the moment. I grew up in North Dakota, and we used to get these wild blizzards. Whiteouts. You’d be driving out on the plains, and the snow would start blowing so hard you’d lose all sense of direction. Blowing so hard it’d make you dizzy just looking at it through the windshield. You’d have to pull over on the side of the road, wait it out. And sitting in the cold car, it was like the world was gone. That’s how I feel right now.”

“I’m scared too. But I’m working this problem.”