We have been walking less than an hour when Bowen, without a word, grabs the sleeve of my shirt and yanks me into a narrow alley between two brick buildings. He shoves me into the shadows and whispers, "Stay!" Balancing his rifle over his shoulder, he crouches at the alley's entrance and takes aim at something I cannot see.

Above the torrent of blood rushing through my body, I hear rain, the pitter-patter of hundreds of drops thudding on the ground. I hold my hand up to the gray sky, but it remains dry. I look up. There is no rain. But the pitter-patter is louder than a moment before, a downpour.

I press my hand to my mouth and stare at Bowen's back. The downpour is not rain. It's footsteps. Lots of them. Running.

Bowen sets his gun down and tears the backpack from his shoulders. With trembling hands, he unzips it and starts pulling things outa"dehydrated food, water bottles, a grenadea"and stops. He holds the grenade in one shaky hand and places the fingers of his other hand on the pin. The muscles in his jaw pulse. I creep to his side and squat so that our shoulders touch.

The rifle is cold and much heavier than it looks. I pick it up, check the safety, balance it on my shoulder, rest my finger on the trigger, and point it out the alley in the direction of the stomping feet. And, side by side, we wait.

The pounding grows steadily louder. My hands begin to sweat, making the gun slippery, making it hard to aim. My shoulder trembles against Bowen's, and I wonder if he can hear my heart trying to explode out of my chest. A lone bead of sweat trickles down my temple.

Bowen's shoulder sags against mine, and he takes his fingers off the grenade pin. I look at him, thinking he must be crazy. He presses a finger to his lips and then touches his ear. I tilt my head to the side and listen. The footsteps are still there, still loud, but fading. To a drizzle. A sprinkle. Silence.

Bowen lets out a sigh and sits on the ground, still balancing the grenade in his hand. I sit beside him and set the rifle down.

"What was that?" I whisper.

"An entire hive is on the move," he says.

"Hive?"

"The beasts. A lot of them. Heading in the direction of the camp." Bowen carefully returns the grenade to his backpack and hands me a water bottle. I drink and pa.s.s it back. "I haven't seen the beasts this stirred up in months. They attacked yesterday, and the day beforea. Something's bothering them." He looks pointedly at me.

"You think it's me causing this unrest?" I ask, stunned.

"Maybe. You're sure creating a lot of unrest for me." He puts his backpack on and peers out of the alley. "Come on. We're almost there."

With the gun now affixed to his shoulder, his finger looped through the trigger, we continue on. I follow a step behind him, my heart jumping at the echo of our feet against the ground, the jingling of his backpack, the scuff of a shoe behind us.

I stop and turn around. A wisp of gray, hardly more substantial than smoke, darts into a building half a block behind us.

"Bowen!" I whisper. Before his name has settled into the air, he is in front of me, gun pointed in the direction I am looking.

"What is it?" he whispers.

"Someone is following us."

He sweeps the rifle left and right. "Are you sure?"

"Positive."

"How many did you see?"

"Just one. He darted into that building." I point.

Bowen slowly lowers his gun, staring at the building.

"Whoever it was is more scared of us than we are of him," he says. "Let's go." He takes my hand and pulls me down the street at a slow jog. I stare at our clasped hands, at the human contact, wondering why it almost makes me want to cry.

Without warning, Bowen yanks me between two buildings and, hand in hand, we start to sprint. Our backpacks thump against our backs, and our feet pound the ground. Within seconds, my legs feel too weak, and a clammy sweat breaks out on my brow. My stomach turns, and I feel as if I haven't eaten in a year.

We round a corner, and Bowen pulls me to a stop in front of a metal door. Light flashes overhead and thunder rumbles. I rest my hands on my knees, gasping trembling breaths of air into my lungs, and peer up at the gray sky. A drip of water splatters against my forehead. And I hear the downpour againa"whether rain or feet, I can't say, because the sky is falling, a thick, cool downpour.

Bowen swears and rams his shoulder into the door. It doesn't budge. He does it again, throwing all of his weight into it.

"I think it's locked," I say. My voice trembles. He ignores me and rams his shoulder into the door a third time with no results. He groans and smacks the door with his fist.

"It's not locked. I glued it shut so that no one else would be able to get in. But the glue should give under pressure." Bowen tries again, but the door doesn't move. He rubs his shoulder and curses.

The downpour is getting louder, though it isn't raining any harder than it was a moment before. Which can mean only one thing. The beasts are closing in. My heart matches the growing throb of their footsteps, and I can see fear in Bowen's eyes.

"We have to run," he says. He reaches for his pack, and I grab his icy hand.

"On three, let's do it together," I say, turning my shoulder toward the door. He stares into my eyes for a moment and then nods.

"One, two, three," Bowen says. I throw myself into the door, expecting it to absorb my momentum. When my shoulder hits, the door swings inward, and Bowen and I fall into the factory, our arms and legs tangled. Bowen wiggles away from me and climbs to his feet, slamming the door and sliding a metal lock into place.

I blink at the darkness. We stand in a huge empty room with one small window in the wall across from the door. The air is stale with dry heat and utterly silent.

Bowen crosses the factory to a narrow staircase in the corner, and I follow. The second level of the factory has windows as tall as me, most of them broken. Rain is blowing through them, pelting my skin, cooling my burned arms. Bowen strides to an empty window and looks out. I follow, but when I get there, he grabs me and pulls me to the side, just behind the window frame, holding my back against his chest with an arm pulled tightly around my shoulders.

"Don't move," he whispers against my ear. "Look."

Thunder rumbles. The wind picks up and whips damp air into my face. The pounding deluge of summer rain swallows the sound of footsteps. Below, two blocks away, runs a large group of people. As one, they stop, fall onto hands and knees, and press their faces to the wet street.

"Are they praying?" I ask.

"Yeah, right. They can't even talk. They're tracking us by scent," Bowen answers. "If they see us a" I press against him, trying to move us out of the window completely. "Just don't move," he whispers, tightening his hold on my shoulders.

The beasts stand and take a few steps forward, then throw themselves down onto the soaked street again. They stand once more and start running. Away from our building. Bowen sags against me, pressing his forehead on my shoulder, and lets out a deep breath of air.

"They lost the scent," he says into my shirt. And then he laughs. He turns me to face him and grins. I can't help but smile back. "The rain washed away the scent!" He runs his hands through his damp hair and sighs again.

I follow him back downstairs, over to the wall with the lone window. He sets his pack down. I do the same and shrug my tight, weary shoulders.

"So, now what?" I ask.

"We hide here until Sunday."

"We're just going to sit in this building for four days?"

"Yep. Bathroom's over there behind that door." He points to a wooden door that's been taken off its hinges and propped at an angle against the wall. "It's nothing fancya"just a bucket and a roll of toilet paper." Bowen sits and faces the metal door we came in through, his back against the cement wall, and lays his gun in his lap. "Might as well make yourself comfortable."

I take the sleeping bag out of my backpack, spread it over the dusty floor, and sit.

"Bowen?" I say. He looks at me. The skin under his eyes is as gray as the world, as gray as the cement wall framing him. "I don't think you brought enough food and water for four days."

His eyebrows rise. "Don't worry about it, Fo. I've got everything under control." He leans his head against the wall again and closes his eyes.

"Bowen," I say again.

"What?" he replies, sounding annoyed.

"Why did you do it?"

He opens his eyes. "Do what?"

"Leave the camp. With me."

"To keep you safe."

"I know, but you risked a lot. I might turn. I might kill you," I say, yet even as I speak the words, I know I could never hurt him.

"You're right. You might turn. And you might have been safe at the camp. But what if you don't turn? What if you are the only person in the world who carries the mark who doesn't go insane? But because of your mark, someone sells you to the black market and you die?" He looks at me for a long time before adding, "I want you to live to have a chance to make it to the lab. I mean, I know youa"have known you my whole life, even if we were never really friends. I think you deserve a chance." He shifts against the wall, sinking into the cement as if it were a pillow. "I need to sleep," he says, shutting his eyes.

I lie down on my side, and the sleeping bag rustles. Bowen's bleary eyes pop open. They're filled with alarm. "I almost forgot," he says. He unzips his backpack and reaches in. I groan when his hand comes out.

I shake my head. "No. Please," I say.

Bowen's jaw hardens. "Fo, the only way I'm ever going to be able to relax with you around is if you're cuffed. I'll just do your ankles."

"I'm not a beast," I whisper.

"If I'm going to protect you sufficiently for four days, I need to sleep. If I don't have peace of mind, I won't be able to sleep. And then we'll both end up dead, because I won't be able to do my job. I promise to release your legs when I wake up."

"And if I refuse? Put up a fight?"

He looks at his gun and then back at me, and his eyes turn cold. "I could always kill you."

I glare at him, and then roll onto my back and glower at the ceiling. Bowen points the remote at me, electricity hums, and the cuffs clink together.

He leans against the wall again, one hand resting on the gun in his lap, the other holding the remote, and is asleep in seconds. I put my hands behind my head and stare at the cobweb-covered ducts attached to the ceiling. My eyelids grow heavy, and I let them fall.

Rain patters outside, and the occasional thunder rumbles, making a fog of sleep settle around my weary, aching body. And then I hear something different. My eyes fly open, and I roll onto my side, wondering if I was dreaming. Every fiber in my body is tensed, right down to my eardrums. Waiting. I hear it againa"the sound of fingernails on a chalkboarda"and I know it was no dream.

The door shakes. The lock rattles against the metal, and dust floats from it. I look at Bowen to see if he heard it, but he's snoring, head sunk to one side. I look back to the door and wait, but nothing happens.

Eventually, weariness overrides fear and I drift off to sleep.

Chapter 17.

The alarm is ringing. My clock radio must have fallen to the floor, because the ringing is m.u.f.fled. I open my eyes and stare at a rectangle of sunlight on a cement floor. No alarm. No carpet. Just cement with a patch of sunlight. And I can't move my legs.

"What the a," someone whispers. I roll onto my side. My shirt clings to my sweaty back. Bowen wipes sleep from his eyes and blinks. He clicks the remote at me and my legs are loose. "Come on." He grabs my hand and pulls me to my feet, hurrying upstairs.

Late-day sunlight glints off water pooled on the floor at the base of the broken windows. A repeating gong, like a church bell, echoes in the humid air. Bowen strides up to a west window and sunlight drenches him, casting a long shadow at his feet.

"You gotta be kidding me," he mutters.

"What is it?" I ask, standing behind him.

"They've opened the gate! For the first time in ever, they opened the gate on a Wednesday! And we're here and not there." He turns accusing eyes onto me. "I could have taken you to the lab right now and been done with you. Now I have to babysit you until Sunday." He shakes his head and pushes past me, grumbling under his breath.

"Gee, thanks. But you're the worst babysitter in the history of the world, Dreyden. Babysitters are supposed to be fun," I say to his back, and then I stick out my tongue. Very thirteen-year-old.

He turns and strides up to me, eyes full of fire, not stopping until our noses nearly touch. I gulp and force myself not to step back. "Nothing about life is fun anymore, Fo," he says. And then he leaves, feet thumping down the stairs.

I turn to the row of west windows and find the one with the least amount of broken gla.s.s below it and sit. The air is heavy with moisture and heat, clinging to my skin, gluing my hair to my scalp. My calves are worse, hot and itchy and sweaty beneath the cuffs. I sift through the gla.s.s shards littering the floor and pick up a long, triangular piece, wrapping it in the hem of my white T-shirt. And then I begin sawing just above my knee. The denim pops and tears against the gla.s.s. When I've made a sufficient hole, I tear the fabric, using the gla.s.s again to cut through the tough seams. And then the bottom half of my jeans separates from the top. I pull the cut denim over my shoe and stare at the glossy black metal encasing my calf.

"Stupid, stupid cuff," I say, and chuck the cut-off piece of denim out the window.

I start on the other leg, hacking at the fabric with the gla.s.s until I can tear it from the rest of the pants. I chuck it, too, and then jab at the metallic cuff encasing my calf. I take a second good, hard jab with the gla.s.s, gouging the metal, and gasp. Instinctively, I throw down the gla.s.s. The T-shirt protecting my hand has a small circle of red on it. The red spreads through the fabric, saturating the fibers, growing. I pull the fabric from my hand, and blood seeps out of a gash in my palm. The sight makes me want to gag.

I stand on weak legs and hurry down the stairs. Bowen, sitting with his back against the wall, gun propped on his bent knees, facing the door, doesn't look at me when I stop in front of him. His face is tight with anger, his brow furrowed.

"Bowen?" I say.

"What?" His eyes don't leave the door.

"Do you have a first-aid kit?" My voice shakes. He looks up, still glowering.

"Why do you need a first-aid kit?" he asks. Blood escapes my cupped hand and drips between his boots. His gun is on the ground and he is on his feet, pulling my hand to his eyes. "How did you manage to get hurt? Wait here." He lets go of my hand, and it falls limply to my side. Blood trickles down my fingers. "And keep your hand above your heart!"

I lift my hand to shoulder height, and blood trails down my arm and drips from my elbow. Bowen is gone for what feels like forever, a whole minute at least. When he comes back, he's holding a white box with a red cross painted on it.

"Upstairs. It's too dark down here," he says, gripping my elbow.

On the second floor, he pushes me to sitting and opens the box. "This will hurt," he warns, "but don't cry out!" He crouches beside me and pulls my fingers flat, making the gash in my palm gape. With his teeth he tears open a small white packeta"it looks like a sugar packet from a restauranta"and holds it over my hand. Our eyes meet. And then his face is over my palm, and he pours little round white beads that look like fertilizer into the open gash. They hiss when they touch blood, and then absorb it until they turn red. The beads expand and the bleeding slows. Pressure fills the wound. I gasp and squeeze my eyes shut. Unable to stay upright, I totter and fall to the side.

Fire laces my blood, spreading from my palm to my fingers and wrist. Ice follows, traveling all the way to my elbow. And then the pain is gone. I wiggle my fingers. It feels like a rock is wedged inside the cut, and I can't make a fist. I take a deep breath and open my eyes. A knee supports my head, and fingers are brushing the hair from my sweaty forehead.

"I'm sorry," Bowen says.

I look up at him. "No. It's my fault for being stupid. I shouldn't have used the gla.s.sa""

"Fo," Bowen snaps, silencing me. "I'm not sorry the coagulant hurt your hand. You totally deserved it. But I'm sorry about what I said. About being stuck with you."

Sunshine spreads through my body. I sit up and beam at him. "Really?"

"Yeah. Really. Aside from you being my potentiala"and most likely, terribly painfula"death, you're not that bad." He smiles and I feel like I could float away. Without asking, he takes my injured hand and wraps it with stretchy tape.