"Before we go anywhere, I want you to eat it."

I've just swallowed the last bit when two doors on opposite sides of the eighth floor slide open. Flashlight beams dance in the darkness. I grab our rope off the balcony, and Lucas and I duck back into his room.

"Are those students?" I ask. "How did they get out?"

"Oh shit," Lucas gasps. "Hide. Hide now!"

"Why? It's just a couple of kids."

"They're not kids," Lucas says. "They're Wolves."

I have time for one regret before Lucas's room is flooded with light. If only I'd left the rope behind on the railing. They might have thought we'd made our escape.

"Well, well, what do we have here?" Caleb and Ivan enter and close the door behind them. Ivan is both confused and elated, as if we've thrown him a surprise birthday party. Caleb still looks bored. "I think we've interrupted a little boy-on-boy action. I do hope that's what this is, Flick. Anything else could prove very embarrassing."

"What are you doing?" I demand.

"Just culling the herd," Caleb says with an exaggerated yawn. "Ivan's going to perform the manual labor. I'm here to supervise. It's one of the perks of being a human resources major."

They've been sent to kill Lucas.

"If you take the pansy," I tell Lucas, "I can handle the ape."

I've barely taken a step when I suddenly discover I'm falling. I hit the ground, unable to move. My muscles are rigid, and the only thing I feel is an unpleasant buzzing. I've been Tasered. Lucas shouts once before he joins me on the floor.

"Let's get them both into the bathroom," Caleb orders.

"Can we kill Flick too?" Ivan asks.

Caleb sighs. "Not tonight, I'm afraid. We aren't authorized to deviate from the plan. But we'll let Flick see what's in store for him, and then if we're lucky, we'll get the order tomorrow."

They prop me up against the wall. Caleb sits on the toilet. Ivan dumps Lucas's body in the bathtub. He pulls on a pair of latex gloves, twists the cold water tap, and then takes a saltshaker from his pants pocket. It's the same kind they use in the cafeteria. He pours the salt into the sink basin and places the empty glass shaker on the floor before crushing it under the heel of his shoe. Then he bends down and sorts through the shards of glass until he finds one that suits his needs.

They're going to make it look like another suicide. But they can't use a razor blade or a knife. None of us are supposed to have access to anything sharp. A piece of glass is the only thing Lucas could realistically use to slash his own wrists.

I am screaming and thrashing inside my head. But I must look a lot like Lucas. Limp. Helpless. The only thing moving are his eyes.

As soon as the tub has filled, Ivan kneels beside it. He pulls Lucas's arms out of the bath and pushes up the boy's sleeves. His movements are so precise that they almost seem gentle. When both of Lucas's wrists are exposed, Ivan chooses one and draws a long, red line with the sharpest edge of the glass. The cut doesn't seem deep enough to do any harm. But when he drops Lucas's limp arm into the bath, a brilliant red flower blooms beneath the water's surface. I watch Lucas's eyes as the second incision is made. For almost a minute I can see only the whites. When his irises finally reappear, I can tell that Lucas is gone.

Ivan drops the shard of glass into the bath. There's not a speck of blood on him.

"Nice work," says Caleb.

"Will they believe he did it himself?"

"Doesn't really matter," Caleb says. "It's all just for show."

Ivan grunts. "What about him?" he asks, prodding my thigh with the tip of his shoe.

"I should give him another zap," Caleb says. "We need to make sure he'll still be here in the morning."

Before he hits me with second jolt of electricity, Caleb squats down. This must be how it feels to come face-to-face with a serial killer. There's no mercy. No trace of a soul. I should have realized that the Wolves all share the same empty eyes.

"I can't wait to see if you manage to talk your way out of this little dilemma," Caleb says.

I don't feel the zap. I just disappear.

CHAPTER SEVENTEEN.

THE HYBRID EXPERIMENT.

I must be dead. I'm in a morgue. The first thing I see is the wall of metal drawers where they store all the corpses. I try to roll my head to the right, but a sharp, searing pain prevents me. I look to the left instead. Lucas is lying on an autopsy table. The blood has been drained from his body, and he's perfectly white. I return my gaze to the ceiling. I won't examine my own body. I don't want to know what they've done.

I hear footsteps approaching. Peter Pan has come for me. I'm finally ready to go.

"Hello, Flick." Mandel's boyish face appears above me. He's wearing a lab coat. I won't be leaving for Never Land. I've been sentenced to hell instead. "You should be able to sit up by now. Here. Let me give you a hand."

He helps me lift my back. I'm naked beneath my hospital gown. The icy steel table chills my balls. My teeth start to chatter, and my skin sprouts goose bumps.

"It's a bit cold in here, isn't it?" Mandel observes. "We'll go somewhere warmer as soon as you're feeling steady enough to stand. In the meantime, there's a question I've been dying to ask you. Would you really have amputated your own arm?"

"What?" My mind is a block of ice, with its memories trapped in the center. I know they're still there. But I can't seem to reach them.

"To get rid of the tracking chip."

I remember now. I wish I didn't. "Yes."

"Fan-tastic!" Mandel exclaims. "My colleagues refused to believe it. But I never doubted you for a second. That's why I took the opportunity to have your chip relocated. It's somewhere much safer now."

I peer down at my arm. There's a bandage where the chip once was. I'm confused for a moment, but then my hand instinctively flies up to the right side of my head. They've hidden the incision under my hair. The chip's there. I can feel it.

"If you're willing to amputate your head, I'll be very impressed," Mandel says. I think he just cracked a joke. "It's only a precaution, of course. Your escape plan was ill-conceived. There was never any chance you'd succeed. After curfew, the balcony railings on floors two through six are electrified. And the security on the ground floor is absolutely impenetrable."

"Why am I still alive?"

"Why wouldn't you be?" Mandel asks. "Everything is going according to plan. Are you ready to take a little stroll?"

I slide off the side of the table. My feet freeze as soon as they touch the tiling. I see three autopsy tables, four lockers, and one desk. There are too many corpse drawers to count. I wonder if they're all occupied.

"Where are we?" I ask.

"The Infirmary floor," Mandel responds. "That's what the employees call it, but my laboratory takes up most of the space. I'll give you a quick tour of the facility before we head upstairs to my office."

"I'm naked," I say.

Mandel glances down at my hospital gown. "Of course! I almost forgot. There's a fresh set of clothes in the locker with my name on it. Go ahead, get dressed. I'll wait for you outside in the lab."

I open the locker. There's a mirror fixed to the inside of the door. I start to get dressed, but it's almost like I've forgotten how. I pull on pants before I remember that boxer shorts should be worn beneath them. And it takes me a moment to remember which go on first-the socks or the shoes. I assume it's the lingering effects of the anesthesia. But when I look in the mirror, I see the truth. While I was under, they didn't just add a chip to my head. They took something away from me too.

Mandel keeps glancing over at me. I think I'm supposed to be oohing and aahing. The narrow aisles make the massive laboratory feel like a labyrinth. All around us, machines hum and whirl and beep. The workers down here seem to understand the strange language. Every new sound sets off a flurry of activity as humans rush to obey the machines' commands. We pause for a moment as a man in a full-body lab suit temporarily blocks our path while he feeds a tray of blood-filled test tubes into a giant white box. All I can see of the man are his eyes. His surgical mask and hood hide the rest.

"What kind of research are you conducting?" I ask my guide. "Who are these people?" I can string words together in my head now, but my tongue still struggles to spit them out.

"Some are neurologists. But most are sequencing DNA. You see, Flick, I'm a geneticist by training. I never thought I'd end up as an educator. My older sister was tapped to run the family business after our mother passed away, but she died in a car accident five years ago. As the only surviving Mandel, I had no choice but to assume control of the school. At first I was extremely annoyed. Then I discovered a way to combine my duty with my true passion."

"By experimenting on dead teenagers," I butt in. "Have you told your doctors where their lab specimens come from?"

"The better you pay people, the fewer questions they ask," Mandel says.

We pass a small room to my right. The door is ajar, and the overhead lights are off. Two females in lab coats are examining a series of backlit blobs that are laid out in a grid on a massive screen. At first I think they're Rorschach blots. Then I realize they're slices of someone's brain.

Mandel sees me lingering and gestures for me to catch up with him. There's a pair of steel doors ahead of us, and he seems impatient to reach them. "Before I took over, the academy used to incinerate the bodies. It always seemed like such a terrible waste to me. Now at least the brains and blood are being put to good use. Mandel Academy students are helping to further the cause of science in ways they never dreamed possible."

"And to think they're just a bunch of kids who flunked out of high school. I'm sure they're thrilled. What exactly are they helping you accomplish?"

"I'm searching for a gene mutation. One that's rewired the brains of some remarkable individuals."

"Let me guess . . ."

"No." Mandel stops me. "Don't guess. Follow me up to my office, and I'll tell you the whole story."

Judging by the angle of the sunbeams that shoot down through the atrium, it must be early afternoon. A bell rings just before our elevator climbs past the classroom floors. I don't know which of the students shouts, but I hear my name echo through the building. Mandel has timed our journey perfectly. He wants everyone at the academy to see us.

"You've just risen from the dead," he tells me. "You used to be a prodigy. Now you're a god."

We step out on the ninth floor, and Mandel uses his card key to open an unmarked door. Behind it lies a staircase. I used to peer out the windows in the Wolves' Den and wonder what might be kept in the identical tower on the opposite side of the roof. Now I know. It's Mandel's private office.

"Interesting choice of decor," I remark when we arrive at the top of the stairs.

Aside from a coatrack standing beside one of the windows, the room is completely empty.

"I work underground. When I come up here, all I want to do is enjoy the view." Mandel sorts through three black coats that are hanging from the rack and passes the largest to me.

"I had this made for you," he says as he chooses one for himself.

The only coat left has a rounded, feminine collar. It looks about the right size for Gwendolyn.

"Has she taken you out to the roof yet?" Mandel asks.

"No."

"Ah well, she's probably been saving it for a special moment. Do try to look surprised when she shows you."

The window next to the coatrack opens like a door. Frigid air rushes into the tower as Mandel steps outside.

My body has a way of warning me when I'm being observed. An unpleasant tingle starts at the top of my spine and spreads until even the tips of my toes are buzzing. After a couple of months at the Mandel Academy, I've learned to live with the sensation. But this is different. It's more than a tingle. It's like I've just jammed a fork into an electric socket. We are out on the roof, surrounded by skyscrapers. I can see my father's building in the distance. His office faces south, overlooking the harbor. He's probably not watching. But others must be.

The academy's glass pyramid sits in the center of the roof. We're on a flat, tar-papered widow's walk between the two towers. A six-foot-high railing lines the edge of the building. Which means I can't just push Mandel over the side. I could try to kill him with my bare hands-but I'd be willing to bet that he's packing a Taser. I'd never make it out of this place alive. And God knows what they'd do to me before I died. Maybe I should shove Mandel through the glass pyramid. Then I could climb the drainpipe on the side of his tower, get past the fence, and jump. If my body splatters on a city street, at least it wouldn't end up in one of those drawers. And that is a very comforting idea.

I could jump. I want to jump. I must jump.

I won't jump. I'm here for a reason. Lucas died to keep me alive. I owe it to him-and to Aubrey and Felix-to do everything I can to survive.

"So how do you like my office?" Mandel laughs. "I know all of this probably seems very cloak and dagger, but I'd prefer to keep our chat private."

"How can you call this private? We're standing on a roof in the middle of the financial district. Half of New York can see us."

"And what do they see? An older man counseling a teenage student? The only thing that matters for now is that no one can hear us. The alumni know about my research, of course. But the experiment I'm currently conducting is the most important of my career. I'm on the cusp of proving a remarkable theory. And I'd like the chance to present all of my findings at once."

"You said you'd made a wager with my father. Now you're conducting an experiment. So what does that make me-your guinea pig?"

"No, Flick. You're going to be my superhero. My Captain America."

Captain America. The dipshit from the Lower East Side who let the government dose him with Super-Soldier serum. As a kid, I thought special powers like his were just another form of cheating. In my opinion, the only true superhero was Batman, who kicked ass without being anything other than human.

"Did you do something to me down there in that lab?" I demand.

Mandel shakes his head as if the question doesn't make sense. "All I did was change the location of your chip. If I altered you physically, it could ruin the experiment."

"Then how do you expect me to become some sort of superhero? I don't even have what it takes to escape from a building in downtown Manhattan."

Mandel beams. I've never seen him so animated. He's practically giddy-like a grade school geek presenting his first science fair project.

"What if I were to tell you that there's a switch somewhere inside you? Until now, it's been in the off position. But if it were on, you would be completely unstoppable. The point of my experiment is to locate that switch-and flip it."

I open my mouth, but Mandel holds up a finger.

"I'll explain everything. But you won't understand unless you allow me to give you a bit of background information." He pauses. "Perhaps you've noticed that some of the students here at the Mandel Academy are . . . different. Caleb and Ivan, for instance. What do you suppose sets them apart?"

I remember Caleb's empty eyes. "They're sociopaths," I say. "I don't know why it took me so long to figure it out. They're both completely insane."

My diagnosis neither shocks nor insults my companion. "Ah, see! You just made two very common mistakes. To begin with, Caleb and Ivan are not sociopaths. They're psychopaths."

"Aren't those the same thing?"

"Not quite. Psychopaths and sociopaths are often confused because they share the same traits. Most are intelligent and cunning, for instance. Many are also remarkably charming. But both groups lack what you'd call a conscience. They always act in their own self-interest. They cheat, steal, or kill to get what they want, and they feel no remorse for their actions. Some-but not all-become criminals. Others find success in a variety of professions.