“For corporate headquarters, of course,” Mom says. She sounds incredulous, as if she were having to explain why ovens aren’t installed in bedrooms. “But the Intercorporate Conventions provide for severe sanctions if employees are targeted at home.”

This dimension puts the whole Coke-versus-Pepsi thing into perspective.

Here, the station gleams an almost pearly white; someone must polish this floor pretty much every hour. But the relative swank factor of subway stations isn’t important. What hits me now is that if I want to see the part of this dimension Triad will never show me—to find Paul and Theo—this is my last chance to vanish into the crowd.

To our far right, I glimpse two signs that read TOILETS—one in blue, one in pink. This is as good a chance as I’ll get. “Hey, I should—”

My mother waves me off as my father smiles. They’re so unsuspecting that I feel a little guilty. But as I walk toward the pink sign, I hear Mom call, “Marguerite? Where are you going?”

Oh, crap. I half turned and tried to smile. “The little girls’ room?”

She points toward the blue sign. “Isn’t blue for girls in your world?”

Here, pink is for boys. It’s the little things that get you. “Oh, okay. Thanks.”

I walk away from them, not too fast. My path intersects with the crowd headed toward the down elevators, and I have to angle my shoulders, step carefully, to keep from bumping into anyone. That gives me a perfectly natural reason to glance backward, and I see my parents talking intently to each other.

I shift direction to merge into the crowd. I walk as quickly as I can without drawing attention to myself, because I won’t be in the clear until I get on one of those elevators. Will I be safe even then? Can my parents track the Firebirds around my neck? Probably, but I have to chance it.

Once I think I’m out of sight, I push forward, earning myself a few glares. But nobody says anything as I edge into an overstuffed elevator just in time for the doors to slide shut only two inches in front of my face.

My heart pounds. My ears tighten and pop with the pressure of descent. At any moment I expect the lights to turn red—or maybe Triad green—and start broadcasting some kind of futuristic APB. But it doesn’t happen. Stop after stop, we keep going down. I decide to get off at the very last stop, wherever that might be. The farther I get away from Triad’s space, the better.

Finally, when I’m one of only three people left inside, the elevator settles with a thump that I know means the end. I walk through the doors, out of the smaller, danker station—and into chaos.

Electronic billboards and signs cover every single surface, all of them shining in colors so strident it almost hurts to look at them. They clash with each other, as do the tinny recordings playing from speakers as ubiquitous as they are invisible:

Apollo Greek Yogurt! Up to 50 percent real dairy!

Explore Your World: Viking Supersonic Air Cruises.

Sentinel upgrades 10 percent off this week only! Isn’t your family’s safety worth it?

Revlon EverLash—Wear Him Out!

Overwhelmed, I tilt my head down, but that doesn’t help; the floor is thickly papered with adhesive posters for shoes, flying cars, movies. (Leonardo DiCaprio again.) Above is no better—it’s the same posters, just less dingy from footprints.

At first I can’t decide whether this is a mall or a street, but then I realize that, in this world, there seems to be no difference. Some stretches are open to the outside, but the stores and the pathways seem to meld into each other. Walking more than five steps without seeing a new product display is impossible.

I think of the trip our family took to Las Vegas for Josie’s high school graduation; it was supposed to be kitschy and hilarious, but instead, we all hated it. I’d envisioned a casino as . . . well, a casino. A distinct building, a place you would enter. Instead, the minute we got off the airplane—still in the airport terminal!—we were bombarded with slot machines. You couldn’t check into the hotel without being surrounded by gift shops and restaurants. Couldn’t get to the elevator after check-in without walking past roulette tables. Vegas was just one big outstretched hand, waiting for your money. That’s what this entire dimension has become.

When I’ve got my bearings, I tuck myself into a corner between two rotating cases of refrigerated, brand-name sandwiches. Then I take up the Firebird and check again for Theo.

The signal suggests he’s right where I am—almost exactly—and I feel a burst of hope before I realize he’s lower than me.

Lots lower.

With a sigh, I fight my way back through the crowd to the next series of down elevators—and the layer under that—and the layer under that. Each time I switch, the ads become more garish; the products they advertise seem cheaper. And the light through the mesh screens dims further at every stop.

When I finally go to what must be the final elevator, someone says, “Young lady.” I turn to see a guy in a vivid pink uniform, which I guess looks super-butch here. “Are you sure you want to do that?”

What, get on the elevator? “Uh, yeah.”

“Below is no place for anyone your age.” The way he says it, I know Below is their name for whatever awaits.

“I’ll be okay,” I say, and I get on the elevator alone. Through the narrowing gap of the closing doors, I see him frown and shake his head.

When the elevator doors open again, only a handful of electronic billboards are here, and they glow dimly, as their images play without sound. The floor is just a floor, and the platforms are open to the air.

Outside, it’s as dark as night.

I walk to the railing and look down; by now, I’m only twenty-five or thirty feet from the ground. Cracked asphalt—more like rubble—is all that remains of what were once sidewalks, or streets. Nobody walks down there. A few people hurry along these almost-deserted walkways beside me, but none of them appear happy to be there. They give me appraising glances; clearly my black clothing sets me apart from the shabbier taupe-and-tan material I see down here. I wonder if I’m about to get mugged. My hand closes around my Firebirds, protectively.

Then I hear the thumping of footsteps—many of them—and hear someone say: “If I’m reading this correctly, she’s just around the corner.”

It’s Theo. I begin to smile as I walk forward to meet them. “Thank God you’re—”

My words trail off. Just from the way he looks at me, hard and flat—I can tell this isn’t my Theo. The one who came here with me is asleep within this world’s version, who doesn’t seem to know me at all. Is this Theo simply tracking an intruder from another dimension?

His whole group goes still. So do I. Because Theo just pulled something black and angular that I’m pretty damn sure is a weapon.

And he’s pointing it at me.

Theo grins. “Not as much fun this time, is it?”

Not one person intercedes on my behalf. The few others walking along this stretch of road determinedly look away, not wanting to get involved. There are no pink-suited cops anywhere near.

I should probably be even more scared than I am, but my brain keeps repeating one phrase over and over.

This time?

“We’ve got her!” Theo calls. He wears his hair longer here, but it sticks up and out rather than growing down; he looks a little like a punk Beethoven. His clothes are baggier and more layered than the stuff worn above, but again it’s all the same color—in this case, a dark burnt orange. “Come on, man, you have to see this!”