"Wouldn't work," he says, almost absently. "More violence just normalizes the killing, it doesn't put an end to it: They're having a party and all you could do is add to the fun . . ."

"Yeah, I—but I'd feel better." Jen had better have bars on her windows and sleep with a baseball bat under her pillow tonight, or she's in trouble. And she royally deserves it, the mendacious bitch.

"Me too, I think."

"Can we do anything?"

"For them?" He shrugs. There's no more screaming, but a tone-deaf choir has struck up some kind of anthem. "No."

I shiver. "Let's go home. Right now."

"Okay," he says, and together we start walking again.

The singing follows us up the road. I'm terrified that if I look back, I'll break down: There's absolutely nothing I can do about it, but I feel a filthy sense of complicity with them. As for Fiore . . . he's got it coming. Sooner or later I'll get him. But I'm going to bite my tongue and not say a word about that for now, because I've a feeling he staged this little show to teach us a lesson about the construction of totalitarian power, and right this moment all the spies and snitches are going to be wide-awake, looking for signs of dissent.

A kilometer up the road and ten minutes away from the ghastly feeding frenzy, I tug at Sam's arm. "Let's slow down a little," I suggest. "Catch our breath. There's no need to run anymore."

"Catch our—" Sam stares at me. "I thought you were mad at me."

"No, it's not you." I carry on walking, but more slowly.

His hand on my arm. "We didn't join in."

I nod, wordlessly.

"Three-quarters of the people there were as horrified as we were. But we couldn't stop it once it got going." He shakes his head.

I take a deep breath. "I'm pissed at myself for not making a stand while there was time. You can game a mob if you know what you're doing. But once people get moving in groups like that, it's really hard to contain them. Fiore didn't need to set that off. But he did, like pouring gasoline on a barbecue." Both of which are items I've only lately become acquainted with. "And after that sermon and the score transfer, he couldn't have stopped it even if he wanted to."

"You sound like you think it's a matter of choice." I glance sidelong at him: Sam's not stupid, but he doesn't normally talk in abstractions. He continues: "Do you really think you could have stopped it? It's implicit in this society, Reeve. They set us up to make it easy to make people kill for an abstraction. You saw Jen. Did you really think you could have stopped her, once she got going?"

"I should have stuck a knife in her ribs." I trudge on in silence for a few seconds. "I'd probably have failed. You're right, but that doesn't make me feel better."

We walk slowly along the road, baking beneath the noonday heat of an artificial late-spring sun in our Sunday outfits. The invertebrates creak in the long, yellowing grass, and the deciduous trees rustle their leaves overhead in the breeze. I smell sage and magnolia in the warm air. Ahead of us the road dives into a cutting that leads to another of the tunnels with built-in T-gates that conceal the true geometry of our inside-out world. Sam pulls out his pocket flashlight, swinging it from his wrist by a strap.

"I've seen mobs before," I tell him. If only I could forget. "They have a peculiar kind of momentum." I feel weak and shaky as I think about it, about the look on Phil's face—I hardly knew him—and the hunger stalking the shadow of the crowd. Jen's malicious delight. "Once it gets past a certain point, all you can do is run away fast and make sure you have nothing to do with what happens next. If everybody did that, there wouldn't be any mobs."

"I guess." Sam sounds subdued as we walk into the penumbra of the tunnel. He switches his flashlight on. The cone of light bobs around crazily ahead of us as the road swings to the left.

"Even a sword-fighting fool of a hero can't divert a mob like that on their own once it gets going," I tell him, as much for my own benefit as anything else. "Not without battle armor and some heavy weaponry, because they're going to keep coming and coming. The ones behind can't see what's happening up front, and the fool who stands in the way without backup is going to end up a dead fool really fast, even if he kills a whole load of them. And anyway, your sword-fighting fool, he's no smarter than any of them in the mob. The time to stop the mob is before it gets started. To stand up in front of it first, and tell it no."

We're walking into the dark curve of the tunnel, out of sight of either entrance. Sam sighs.

"I knew someone who'd do that," he says wistfully. "The man I fell in love with. He wasn't a fool, but he'd know how to handle a situation like that."

The man ? Sam doesn't seem like the type to me—until I remember that I'm seeing him through gender-trapped eyes, the same way he's looking at me, and that I've got no way of knowing who or what Sam was before he volunteered for the experiment. "Nobody could do that," I tell him gently.

"Maybe so. But I think I'd trust Robin's judgment before I'd trust—"

I stop as suddenly as if I have just walked into a wall. The hairs on the back of my neck are all standing on end, and my stomach is knotting up again as if I'm going to be sick.

"What's wrong?" asks Sam.

"The person on the outside you've been pining after," I say carefully. "He's called Robin. Is that right?"

"Yes." He nods. "I shouldn't have said, we'll get penalized—"

I grab his hand like it's a floatation aid and I'm drowning. "Sam, Sam." You idiot! Yes, you! (I'm not sure which of us I mean.) "Did it ever occur to you to ask if maybe I knew Robin?"

"Why? What good would that have done?" His pupils are huge and dark in the twilight.

"You are the biggest—" I don't know what to say. Truly, I don't. Stunned is the mildest word that describes how I feel. "The name you gave Robin was Kay, right?"

"You—"

"Kay. Yes or no?"

He tenses and tries to pull his hand away. "Yes," he admits.

"O-kay." I don't seem to be able to get enough air. "Well, Sam, we are going to continue on our way home, now, aren't we? Because who we were before we came here doesn't make any difference to where we are now, does it?"

His expression is impossible to read in the darkness. "You must be Vhora—"

I nearly slap him. Instead, I reach out with the index finger of my free hand and touch his lips. "Home first. Then we talk," I tell him, stomach still churning, aghast at my own stupidity and willful blindness. Okay, so I walked right into this one. And I think I just sprained my brain. Now what?

He sighs. "All right." He still doesn't use my name. But he turns to shine the flashlight ahead of us. And that's when I see the outline of the door in the opposite wall.

IT'S funny how the more we travel the less we see.

Traveling via T-gates, we avoid the intervening points between the nodes because the gate is actually a hole in the structure of space, and in a very real sense there are no intervening points. And it's not much different in a car. You get in, you tell the zombie where to take you, and he steps on the gas. Not that there's a machine under the bonnet that clatteringly detonates liquid distilled from ancient fossilized biomass (just a compact gateway generator and a sound effects unit), but it feels the same, in terms of your interaction with your surroundings.

Meanwhile, outside the cars and the corridors and the gates and the head games we deny playing with each other, there's a real universe. And sometimes it smacks you in the face.

Like now. I have known all along, in an abstract kind of way, that we're living in a series of roughly rectangular terrain features laid out on the curved inner surface of several huge colony cylinders, spinning to provide centripetal acceleration (a substitute for gravity), in orbit around who-knows-what brown dwarf stars. The sky is a display screen, the wind is air-conditioning, the road tunnels are a necessary part of the illusion, and if you go for a walk in the overgrown back lot you'll find a steep hill or cliff that you can't climb because it goes vertical only a few meters up. I haven't given much thought to how it's all stitched together, other than to assume there are T-gates in each road tunnel. But what if there's another way out?