I instinctively raise my spear. Josh's voice comes crackling through the speaker in my helmet. "Easy, Becky. Remember what I told you. Just stand still for the time being and chill."

"Chill my arse," I mutter sourly, but I lower the spear and watch nervously as the zombies draw closer.

The first to come within striking distance is a woman. She's dressed in a filthy, tattered green blouse and a matching skirt. There are bite marks up and down her arms, as if her boyfriend got out of control when they were making out. Her eyes have a gray, cloudy film over them, like a blind person's, but by the way she focuses on me, I'm sure that she can see well enough.

The woman pauses in front of me and sniffs the air. Her mouth is open and her long, sharp teeth are bared. She makes a growling sound and I think she's getting ready to attack. My fingers tighten on the spear. But then she reels away to sniff the others.

I'm not sweating inside my helmet - I can't - but I feel hotter than normal. I keep a close eye on the zombies as they shuffle around, staring, sniffing, fingers twitching. I keep expecting one to realize that we're different, attack and set off the rest of their undead pack. But they don't. Because we're not that different, not in the most important way - like them, we're dead. Zombies clearly only have a taste for the living.

"That's good," Josh murmurs. "Let them get used to you."

"This is freaking me out," I croak.

"No," he says. "You've adjusted faster than the others did. You're the first to hold your nerve when making primary contact with reviveds. Even Rage lashed out the first time he was exposed."

That makes me feel smug. Of course it could be a load of bull and Josh might be saying it just to settle me down, but who can resist flattery like that? I treat myself to a self-indulgent chuckle, imagining Rage in a panic. I'll tease him about that later.

We hold our ground, letting the zombies move around freely. They don't have much interest in anything, not even each other. They creep in their own directions, swiveling to avoid collisions when they catch sight of one another but not communicating or cooperating in any clear way.

I start to feel sorry for them. They were real people once, with families, jobs, friends, hopes, dreams. What if some small part of them is still alive in there, if they can sense what they've become? How awful would that be?

"Okay," Josh says. "We're going to shake things up a bit. Raise your spear."

I hold it up as Josh instructs, then wave it threateningly at a passing zombie.

The zombie doesn't react.

"Do it again," Josh says. "But yell this time."

I roar at a different zombie - a man - and poke my spear at him, but he ignores me like the first one did.

The other zom heads make threatening gestures too, reacting to instructions. We must each have a separate guide, someone to direct us individually.

"Back up closer to the others," Josh says. "Form a tighter circle, so the reviveds can't pass between you."

I ease back as ordered, until my elbows brush against Danny's and Gokhan's. Danny has a chainsaw, Gokhan an ax.

"Exciting, innit?" Gokhan shouts, raising the visor of his helmet to grin at me.

The zombies close to us pause when they hear him shout and they stare at him, eyes wide and gray. "Yeah," Gokhan jeers. "You didn't expect me to talk, did you? You don't understand anything. We're gonna stomp your ugly arses. I'll cut your heads off with this ax and scoop out your brains. What do you think of that, eh?"

The zombies carry on walking, oblivious to the threat. Gokhan laughs and lowers his visor.

"Get ready for action," Josh whispers.

Rage has scorched the ceiling a couple of times, sending flames licking over the heads of the zombies. A couple of them cringed but didn't otherwise react. Now he lowers his hose, points the nozzle at a thin young woman and lets rip. Fire consumes her and she wheels away from him, screaming hoarsely, arms flapping, head shaking wildly.

The other reviveds come to a standstill. Their heads whip round and all eyes settle on Rage.

"Come on, you bastards," Rage growls.

As if in direct response to his challenge, they attack.

Instant chaos. Rage sprays the zombies with flames, and so does Tiberius, who has the other flamethrower. But they can't cover all angles and moments later the zombies are on us, digging at our stomachs with the bones sticking out of their fingers, gnashing at our faces, hissing and screeching.

I jab at a couple of my assailants, driving them back. The other zom heads are going wild. Cathy and Danny's chainsaws are alive and buzzing. Peder and Gokhan are chopping madly at the zombies, snickering hysterically.

Cathy digs the head of her chainsaw into a man's stomach and grinds it around. Blood and guts spray everywhere. The man falls away, screaming, a massive hole through his body where his middle should be. But that's not the end of him. Even though he's shrieking with agony, he crawls towards us, innards dribbling out and smearing the floor, driven to keep coming by a force beyond his control. His eyes are wild. Blood foams from his lips. He shudders and spasms like someone being electrocuted. But still he comes on.

"My go!" Peder cheers and chops at the man's neck until he severs it. With a sick laugh, he picks up the head by its hair and waves it around. The man's mouth is still opening and closing. His eyes still work. His arms still writhe on the now headless body and his legs kick out feebly at nothing.

Peder throws the head across the room and it bounces off a wall. The man's body somehow struggles to its feet and staggers around, arms flailing, trying to find his head. I'm appalled - if I had a heart, it would go out to the distressed zombie - but the others are having a ball.

"Can I go help him?" Danny yells gleefully. He must receive a positive answer because he breaks away and dashes across the room. Rage and Tiberius cover him, training their fire on the zombies who target him.

Danny grabs the headless body and hauls it over to where the head is lying. He picks up the severed head and sticks it on the neck, but back to front. With a ghoulish giggle, he returns to the ranks and restarts his chainsaw.

I stare with horror as the man swivels several times, trying to work out what's wrong. Finally his head falls off again. His body bends and his arms search for the missing head. Finding it, he puts it back in place, but the right way round this time. He holds the head in place by crooking an arm over it. With a snarl, he hurls himself back into the action and throws himself at me.

I'm frozen with shock, hardly able to believe the joy with which the zom heads have gone about their cruel business. Reacting instinctively when I'm attacked, I jab at the man's stomach, but of course there's nothing there, so my spear passes straight through the hole. Before I can pull it back, he's on me, eyes wide with crazy rage, teeth snapping together as he tries to chew through my helmet.

"Protect yourself!" Josh shouts.

I shove the man away, but he catches on the spear and doesn't fall. He bounces back towards me and his head collides with mine. His arm slips and his head falls to the floor, but the force of the collision cracks the glass in my visor. With a shriek of alarm, I push his body away, readjust my grip on my spear, then drive it down into the man's skull, all the way through his brain.

I lift the spear and the man's head rises into sight. His lips are trembling and he's making an awful choking noise. Blood drips from his neck and spatters my gloved hands. His eyes stare at me through the cracked lens of my visor. It might be my imagination, but I think I see fear in his expression.

"Cool!" Cathy exclaims, then sprays the head with flames. The stench of burning flesh and hair fills my nostrils and I gag. If I'd eaten anything recently, I'm sure I'd throw up, but my stomach is empty, so I only dry heave.

"Sod this!" I cry, and throw my spear away.

"Becky," Josh snaps. "What are you doing?"

Losing all control, I step away from the others and rip loose my helmet, freeing my face.

"Replace that!" Josh yells. "Get back in line!"

In answer I scream wordlessly, a monstrous howl. The world tilts crazily around me. I can't take this anymore. I want it to stop.

I clamp my hands over my ears and try to shut my eyes. When I remember that I can't, I scream again and grab the spear. I kick the flaming head off of it, then snap the shaft in two. I point the half with the tip at my eyes, determined to blind myself to this nightmarish spectacle, maybe even dig around, rip out my brain and finish the job that Tyler started all those months ago.

Rage knocks my arm aside. I bring it up to try again but he grabs my hand and forces it down, then wrestles the spear from my fingers and tosses it away.

I curse Rage and swing for him with my fists. Zombies crowd around and tear and snap at us. I feel bones scrape down the back of my exposed neck. I shriek madly and roar them on to success. Rage swears and punches me. My nose pops and blood oozes out. I choke on it, shake my head, scream again.

Then nets start to come down on the zombies. Panels are ripped aside and soldiers fire through the gaps, shooting any revived who isn't caught. I try to pull free of Rage, to hurl myself into the hail of bullets, wanting to perish along with the zombies, feeling closer to them than to any of these warped, tormenting creeps. This is a savage, dreadful world, and I want out. I wish I'd never been brought back to life. I want to end it, stop it all, get off the moving train.

A net falls around me and I get tangled up. I lash out with both arms, trying to tear free, but the net only tightens further. With another scream, this time born of frustration at being cheated out of the death I crave, I fall to the floor and thrash around weakly, trapped in this living hell, forced to continue by the soldiers and scientists who gather round me once the zombies have all been killed or subdued. They stare at me coldly and listen to me shower them with abuse.

I'm still screaming when a man pushes through the others and crouches next to me. "Stop it, B," he says softly.

I ignore him, thinking it's Josh or Dr. Cerveris.

"Stop that," the man says again. When I don't, he grabs the netting around my head, ignoring the warning cries of the soldiers, and jerks my face towards his. "Look at me!" he barks.

I try to spit at him but my mouth is too dry.

"Look at me," the man says again, quieter this time, and something in his tone makes me pause. It's not Josh or Dr. Cerveris, but his voice is familiar.

Suppressing the scream that was building at the back of my throat, I focus on the light brown face in front of me and gasp. "Mr. Burke?"

"Yes," he says, then grabs my gloved hand and squeezes reassuringly. "You can relax now. I'm here for you, B."

I'm so astonished, I can't say anything else, and I don't resist as two soldiers haul me to my feet, cut away the net from around my feet, and force me out of the room, Billy Burke - my favorite teacher from school - incredibly, impossibly, following close behind.