"We've tried," Dr. Pam says. "Drugs, radiation, electroshock, surgery. Nothing works. The only way to kill them is to kill the host."

She slides the keyboard in front of me. "He won't feel anything."

Confused, I shake my head. I don't get it.

"It lasts less than a second," Dr. Pam assures me. "And it's completely painless. This button right here."

I look down at the button. It has a label: EXECUTE.

"You're not killing Chris. You're destroying the thing inside him that would kill you."

"He had his chance to kill me," I argue. Shaking my head. It's too much. I can't deal. "And he didn't. He kept me alive."

"Because it wasn't time yet. He left you before the attack, didn't he?"

I nod. I'm looking at him again through the two-way mirror, through the indistinct frame of my see-through self.

"You're killing the things that are responsible for this." She presses something into my hand.

Sissy's locket.

Her locket, the button, and Chris. And the thing inside Chris.

And me. Or what's left of me. What's left of me? What do I have left? The metal links of Sissy's necklace cut into my palm.

"It's how we stop them," Dr. Pam urges me. "Before there's no one left to stop them."

Chris in the chair. The locket in my hand. How long have I been running? Running, running, running. Christ, I'm sick of running. I should have stayed. I should have faced it. If I had faced it then, I wouldn't be facing it now, but sooner or later you have to choose between running and facing the thing you thought you could not face.

I bring my finger down as hard as I can.

30.

I LIKE THE CONVALESCENT WING a lot more than the Zombie Ward. It smells better, for one thing, and you get your own room. You're not stuck out on the floor with a hundred other people. The room is quiet and private, and it's easy to pretend the world is what it was before the attacks. For the first time in weeks, I'm able to eat solid food and make it to the bathroom by myself-though I avoid looking in the mirror. The days seem brighter, but the nights are bad: Every time I close my eyes, I see my skeletal self in the execution room, Chris strapped down in the room on the other side, and my bony finger coming down.

Chris is gone. Well, according to Dr. Pam, Chris never was. There was the thing inside Chris controlling him that had embedded itself into his brain (they don't know how) sometime in the past (they don't know when). No aliens descended from the mothership to attack Wright-Patterson. The attack came from within, with infested soldiers turning their guns on their comrades. Which meant they had been hiding inside us for a long time, waiting for the first three waves to whittle our population down to a manageable number before revealing themselves.

What did Chris say? They know how we think.

They knew we'd seek safety in numbers. Knew we'd take shelter with the guys who had guns. So, Mr. Alien, how do you overcome that? It's simple, because you know how we think, don't you? You embed sleeper units where the guns are. Even if your troops fail in the initial assault, like they did at Wright-Patterson, you succeed in your ultimate goal of blowing society apart. If the enemy looks just like you, how do you fight him?

At that point, it's game over. Starvation, disease, wild animals: It's only a matter of time before the last, isolated survivors are dead.

From my window six stories up I can see the front gates. Around dusk, a convoy of old yellow school buses rolls out, escorted by Humvees. The buses return several hours later loaded down with people, mostly kids-though it's hard to tell in the dark-who are taken into the hangar to be tagged and bagged, the "infested" winnowed out and destroyed. That's what my nurses tell me, anyway. To me, the whole thing seems crazy, given what we know about the attacks. How did they kill so many of us so quickly? Oh yeah, because humans herd like sheep! And now here we are, clustering again. Right in plain sight. We might as well paint a big red bull's-eye on the base. Here we are! Fire when ready!

And I can't take it anymore.

Even as my body grows stronger, my spirit begins to crumple.

I really don't get it. What's the point? Not their point; that's been pretty damn clear from the beginning.

I mean what's the point of us anymore? I'm sure if we didn't cluster again, they'd have another plan, even if that plan were using infested assassins to take us out one stupid, isolated human at a time.

There's no winning. If I had somehow saved my sister, it wouldn't have mattered. I would have bought her another month or two tops.

We're the dead. There's no one else now. There's the past-dead and the future-dead. Corpses and corpses-to-be.

Somewhere between the basement room and this room, I lost Sissy's locket. I wake up in the middle of the night, my hand clutching empty air, and I hear her screaming my name like she's standing two feet away, and I'm furious, I'm pissed as hell, and I tell her to shut up, I lost it, it's gone. I'm dead like her, doesn't she get it? A zombie, that's me.

I stop eating. I refuse my meds. I lie in bed for hours, staring at the ceiling, waiting for it to be over, waiting to join my sister and the seven billion other lucky ones. The virus that was eating me has been replaced by a different disease that's even more hungry. A disease with a kill rate of 100 percent. And I tell myself, Don't let them do it, man! This is part of their plan, too, but it doesn't do any good. I can give myself pep talks all day long; it doesn't change the fact that the moment the mothership appeared in the sky, it was game over. Not a matter of if, but when.

And right when I reach the point of no return, when the last part of me able to fight is about to die, as if he's been waiting all this time for me to reach that point, my savior appears.

The door opens and his shadow fills the space-tall, lean, hard-edged, as if his shadow were cut from a slab of black marble. That shadow falls over me as he walks toward the bed. I want to look away, but I can't. His eyes-cold and blue as a mountain lake-pin me down. He comes into the light, and I can see his short-cropped sandy hair and his sharp nose and his thin lips drawn tight in a humorless smile. Crisp uniform. Shiny black boots. The officer insignia on his collar.

He looks down at me in silence for a long, uncomfortable moment. Why can't I look away from those ice-blue eyes? His face is so chiseled it looks unreal, like a wood carving of a human face.

"Do you know who I am?" he asks. His voice is deep, very deep, a voice-over-on-a-movie-preview deep. I shake my head. How the hell could I know that? I'd never seen him before in my life.

"I'm Lieutenant Colonel Alexander Vosch, the commander of this base."

He doesn't offer me his hand. He just stares at me. Steps around to the end of the bed, looks at my chart. My heart is pounding hard. It feels like I've been called to the principal's office.

"Lungs good. Heart rate, blood pressure. Everything's good." He hangs the chart back on the hook. "Only everything isn't good, is it? In fact, everything is pretty damn bad."

He pulls a chair close to the bed and sits down. The motion is seamless, smooth, uncomplicated, like he's practiced it for hours and gotten sitting down to an exact science. He adjusts the crease in his pants into a perfectly straight line before he goes on.

"I've seen your Wonderland profile. Very interesting. And very instructive."

He reaches into his pocket, again with so much grace that it's more like a dance move than a gesture, and pulls out Sissy's silver locket.

"I believe this is yours."

He drops it on the bed next to my hand. Waits for me to grab it. I force myself to lie still, I'm not sure why.

His hand returns to his breast pocket. He tosses a wallet-size photo into my lap. I pick it up. There's a little blond kid around six, maybe seven. With Vosch's eyes. Being held in the arms of a pretty lady around Vosch's age.

"You know who they are?"

Not a hard question. I nod. For some reason, the picture bothers me. I hold it out for him to take back. He doesn't.

"They're my silver chain," he says.

"I'm sorry," I say, because I don't know what else to say.

"They didn't have to do it this way, you know. Have you thought about that? They could have taken their own sweet time killing us-so why did they decide to kill us so quickly? Why send down a plague that kills nine out of every ten people? Why not seven out of ten? Why not five? In other words, what's their damn hurry? I have a theory about that. Would you like to hear it?"

No, I think. I wouldn't. Who is this guy, and why is he here talking to me?

"There's a quote from Stalin," he says. "'A single death is a tragedy; a million is a statistic.' Can you imagine seven billion of anything? I have trouble doing it. It pushes the limits of our ability to comprehend. And that's exactly why they did it. Like running up the score in football. You played football, right? It isn't about destroying our capability to fight so much as crushing our will to fight."

He takes the photograph and slips it back into his pocket. "So I don't think about the 6.98 billion people. I think about just two."

He nods toward Sissy's locket. "You left her. When she needed you, you ran. And you're still running. Don't you think it's time you stop running and fight for her?"

I open my mouth, and whatever I meant to say comes out as, "She's dead."

He waves his hand in the air. I'm being stupid. "We're all dead, son. Some of us are just a little further along than others. You're wondering who the hell I am and why I'm here. Well, I told you who I am, and now I'm going to tell you why I'm here."

"Good," I whisper. Maybe after he tells me, he'll leave me alone. He's weirding me out. Something about the way he looks at me with that icy stare, the-there's no other word for it-hardness of him, like he's a statue come to life.

"I'm here because they've killed almost all of us, but not all of us. And that's their mistake, son. That's the flaw in their plan. Because if you don't kill all of us all at once, whoever's left are not going to be the weak ones. The strong ones-and only the strong ones-will survive. The bent but unbroken, if you know what I mean. People like me. And people like you."

I'm shaking my head. "I'm not strong."

"Well, that's where you and I will have to disagree. You see, Wonderland doesn't just map out your experiences; it maps out you. It tells us not just who you are, but what you are. Your past and your potential. And your potential, I kid you not, is off the charts. You are exactly what we need at exactly the time we need it."

He stands up. Towering over me. "Get up."

Not a request. His voice is as rock hard as his features. I heave myself onto the floor. He brings his face close to mine and says in a low, dangerous voice, "What do you want? Be honest."

"I want you to leave."

"No." Shaking his head sharply. "What do you want?"

I feel my lower lip poking out, like a tiny kid about to collapse completely. My eyes are burning. I bite down hard on the edges of my tongue and force myself not to look away from the cold fire in his eyes.

"Do you want to die?"

Do I nod? I can't remember. Maybe I did, because he says, "I'm not going to let you. So now what?"

"So I guess I'm going to live."

"No, you're not. You're going to die. You're going to die, and there's nothing you or I or anyone else can do to stop it. You, me, everyone left on this big, beautiful blue planet is going to die and make way for them."

He's cut right to the heart of it. It's the perfect thing to say at the perfect moment, and what he's been trying to get out of me suddenly explodes.

"Then what's the point, huh?" I shout into his face. "What's the fucking point? You have all the answers, so you tell me, because I have no idea anymore why I should give a damn!"

He grabs me by the arm and slings me toward the window. He's beside me in two seconds and flings open the curtain. I see the school buses idling beside the hangar and a line of children waiting to go inside.

"You're asking the wrong person," he snarls. "Ask them why you should give a damn. Tell them there's no point. Tell them you want to die."

He grabs my shoulders and whirls me around to face him. Slaps me hard in the chest.

"They've flipped the natural order on us, boy. Better to die than live. Better to give up than fight. Better to hide than face. They know the way to break us is to kill us first here." Slapping my chest again. "The final battle for this planet will not be fought over any plain or mountain or jungle or desert or ocean. It will happen here." Popping me again. Hard. Pop, pop, pop.

And I'm totally gone by this point, giving in to everything I've bottled up inside since the night my sister died, sobbing like I've never cried before, like crying is something new to me and I like the way it feels.

"You are the human clay," Vosch whispers fiercely in my ear. "And I am Michelangelo. I am the master builder, and you will be my masterpiece." Pale blue fire in his eyes, burning to the bottom of my soul. "God doesn't call the equipped, son. God equips the called. And you have been called."

He leaves me with a promise. The words burn so hot in my mind, the promise follows me into the deepest hours of the night and into the days that follow.

I will teach you to love death. I will empty you of grief and guilt and self-pity and fill you up with hate and cunning and the spirit of vengeance. I will make my final stand here, Benjamin Thomas Parish.

Slapping my chest over and over until my skin burns, my heart on fire. And you will be my battlefield.

31.

IT SHOULD have been easy. All he had to do was wait.

He was very good at waiting. He could crouch for hours, motionless, silent, he and his rifle one body, one mind, the line fuzzy between where he ended and the weapon began. Even the fired bullet seemed connected to him, bound by an invisible cord to his heart, until the bullet wedded bone.

The first shot dropped her, and he quickly fired again, missing entirely. A third shot as she dived to the ground beside the car, and the back window of the Buick exploded in a cloud of pulverized shatterproof glass.

She'd gone under the car. Her only option, really, which left him two: wait for her to come out or leave his position in the woods bordering the highway and end it. The option with the least risk was staying put. If she crawled out, he would kill her. If she didn't, time would.

He reloaded slowly, with the deliberateness of someone who knows he has all the time in the world. After days of stalking her, he guessed she wasn't going anywhere. She was too smart for that. Three shots had failed to take her down, but she understood the odds of a fourth missing. What had she written in her diary?

In the end it wouldn't be the lucky ones left standing.

She would play the odds. Crawling out had zero chance of success. She couldn't run, and even if she could, she didn't know in which direction safety lay. Her only hope was for him to abandon his hiding place and force the issue. Then anything was possible. She might even get lucky and shoot him first.

If there was a confrontation, he didn't doubt she would refuse to go down quietly. He had seen what she did to the soldier in the convenience store. She may have been terrified at the time, and killing him may have bothered her afterward, but her fear and guilt didn't stop her from filling his body with lead. Fear didn't paralyze Cassie Sullivan, like it did some humans. Fear crystallized her reason, hardened her will, clarified her options. Fear would keep her under the car, not because she was afraid of coming out, but because staying there was her only hope of staying alive.

So he would wait. He had hours before nightfall. By then, she would have either bled to death or be so weak from blood loss and dehydration that finishing her would be easy.

Finishing her. Finishing Cassie. Not Cassie for Cassandra. Or Cassie for Cassidy. Cassie for Cassiopeia, the girl in the woods who slept with a teddy bear in one hand and a rifle in the other. The girl with the strawberry blond curls who stood a little over five feet four in her bare feet, so young-looking he was surprised to learn she was sixteen. The girl who sobbed in the pitch black of the deep woods, terrified one moment, defiant the next, wondering if she was the last person on Earth, while he, the hunter, hunkered a dozen feet away, listening to her cry until exhaustion carried her down into a restless sleep. The perfect time to slip silently into her camp, put the gun to her head, and finish her. Because that's what he did. That's what he was: a finisher.

He had been finishing humans since the advent of the plague. For four years now, since he was fourteen, when he awakened inside the human body chosen for him, he had known what he was. Finisher. Hunter. Assassin. The name didn't matter. Cassie's name for him, Silencer, was as good as any. It described his purpose: to snuff out the human noise.

But he didn't that night. Or the nights that followed. And each night, creeping a little closer to the tent, inching his way over the woodland blanket of decaying leaves and moist loamy soil until his shadow rose in the narrow opening of the tent and fell over her, and the tent was filled with her smell, and there would be the sleeping girl clutching the teddy bear and the hunter holding his gun, one dreaming of the life that was taken from her, the other thinking of the life he'd take. The girl sleeping and the finisher, willing himself to finish her.