That’s when it hits me: The shimmering worry at the edge of my thoughts swells and breaks over me. This is wrong—all wrong. This is too organized. There are too many rooms, too many weapons, too much order.

“They must have had help,” I say, as the idea occurs to me for the first time. “The Scavengers could never have done this on their own.”

“The who?” Julian asks impatiently, casting an anxious look at the door.

I know we have to go, but I can’t move; a tingling feeling is working its way from my toes up into my legs. There’s another idea flickering in the back of my mind now—a brief impression, something seen or remembered. “Scavengers. They’re uncureds.”

“Invalids,” Julian says flatly. “Like you.”

“No. Not like me, and not Invalids. Different.” I squeeze my eyes shut and the memory crystallizes: pressing the point of my knife into the flesh below the Scavenger’s jaw, just above faint blue markings that looked somehow familiar…

“Oh my God.” I open my eyes. My chest feels as though someone is pounding on it.

“Lena, we have to go.” Julian reaches out to grab my arm, but I pull away from him.

“The DFA.” I can barely croak out the words. “The guy—the guard back there, the one we tied up—he had a tattoo of an eagle and a syringe. That’s the DFA crest.”

Julian stiffens. It’s as though a current has run through his whole body. “It must be a coincidence.”

I shake my head. Words, ideas, are tumbling through my head, a stream: Everything flows one way. Everything makes sense: talk of payday; all this equipment; the tattoo; the box of badges. The complex, the security—all of it costs money. “They must be working together. I don’t know why, or what for, or—”

“No.” Julian’s voice is low and steely. “You’re wrong.”

“Julian—”

He cuts me off. “You’re wrong, do you understand me? It’s impossible.”

I force myself not to look away from him, even though there’s something strange going on behind his eyes, a roiling and swirling that makes me feel dizzy, as though I’m standing on the edge of a cliff and in danger of falling.

That’s how we’re standing—frozen like that, a tableau—when the door bangs open and two Scavengers burst into the room.

For a second nobody moves, and I have just enough time to register the basics: one guy (middle-aged), one girl (blue-black hair, taller than I am), both of them unfamiliar. Maybe it’s the fear, but I fixate, too, on the strangest details: the way the man’s left eyelid droops, as though gravity is pulling on it, and the way the girl stands there, mouth open, so I can see her cherry-red tongue. She must have been sucking on something, I think. A lollipop or candy; my mind flies to Grace.

Then the room unfreezes, and the girl goes for her gun, and there’s no thinking anymore.

I lunge at her, knocking the gun from her hand before she has the chance to level it at me. Behind me, Julian shouts something. There’s a gunshot. I can’t look to see who fired. The girl swings at me, clipping me on the jaw with her fist. I’ve never been punched before, and it’s the shock of it, more than the pain, that stuns me. In that split second she manages to get her knife out, and the next thing I see is the blade whistling toward me. I duck, drive hard into her stomach with my shoulders.

She grunts. The momentum carries us both off our feet, and we tumble backward into a box of old shoes. The cardboard collapses under our weight. We’re grappling so close I can taste her hair, her skin in my mouth. First I’m on top, straining, then she is, flipping me down onto my back so my head slams against the concrete, her knees hard in my ribs, thighs gripping me so tight the air is getting squeezed from my lungs. She’s wrestling another knife free of her belt. I’m scrabbling on the floor for a weapon—any weapon—but she’s on me too hard, is gripping me too tightly, and my fingers are closing on air and concrete.

Julian and the man are locked in a shuffling embrace, both straining for an advantage, heads down, grunting. They swivel hard and hit a low wooden bookshelf filled with pots and pans. It teeters, teeters, and then falls: the pots spill everywhere, a cacophony of ringing and dinging metal. The girl glances backward and just that, that little shift, gives me enough room to move. I rocket my fist up, connecting with the side of her face. It can’t hurt too badly, but it sends her sideways and off me, and I’m up and rolling on top of her, ripping the knife out of her grip. My hatred and fear is flowing hard and electric and hot, and without thinking about it I lift the blade and drive it hard down into her chest. She jerks once, lets out a cry, and then goes still. My mind is a loop, an endless refrain: your-fault-your-fault-your-fault. There’s a mangled sobbing sound coming from somewhere, and it takes me a long time to realize I’m the one crying.

Then everything goes black for a moment—the pain comes a split second after the darkness—as the other Scavenger, the man, catches me on the side of my head with a baton. There’s a thunderous crack; I’m tumbling, and everything is a blur of disconnected images: Julian lying facedown near the toppled shelf; a grandfather clock in the corner I hadn’t noticed before; cracks in the concrete floor, expanding like a web to embrace me. Then a few seconds of nothing. Jump-cut: I’m on my back, the ceiling is revolving above me. I’m dying. Weirdly enough, I think of Julian. He put up a pretty good fight.

The man is on top of me, breathing hot and hard into my face. His breath smells like something spoiling in a closed place. A long, jagged cut runs under his eye—nice one, Julian—and some of his blood drips onto my face. I feel the razor-bite of a knife under my chin, and everything in my body freezes. I go absolutely still.

He’s staring at me with such hatred I suddenly feel very calm. I will die. He will kill me. The certainty relaxes me. I am sinking into a white snow. I close my eyes and try to picture Alex the way I used to dream of him, standing at the end of a tunnel. I wait for him to appear, to reach out his hands to me.

I’m fading in and out. I’m hovering above the ground; then I’m on the floor again. There’s the taste of swamp in my throat.

“You gave me no choice,” the Scavenger pants out, and I snap my eyes open. There’s a note of something there—regret, maybe, or apology—that I didn’t anticipate. And with that, the hope comes rushing back, and the terror, too: Please-please-please-let-me-live.

But just then he inhales and tenses, and the point of the knife breaks through my skin and it’s too late—

Then he jerks, suddenly, on top of me.

The knife clatters out of his hand. His eyes roll up to the ceiling, terrible, a doll’s blank gaze. He falls forward slowly, on top of me, knocking the air out of my chest. Julian is standing above him, breathing hard, shaking. The handle of a knife is sticking out of the Scavenger’s back.

A dead man is lying on top of me. A hysterical feeling builds in my chest, then breaks, and suddenly I am babbling, “Get him off of me. Get him off of me!”

Julian shakes his head, dazed. “I—I didn’t mean to.”

“For God’s sake, Julian. Get him off of me! We have to go now.”

He starts, blinks, and focuses on me. The Scavenger’s weight is crushing.

“Please, Julian.”

Finally Julian moves. He bends down and heaves the body off me, and I scramble to my feet. My heart is racing and my skin is crawling; I have the desperate urge to bathe, to get all that death off me. The two dead Scavengers lie so close to each other they are almost touching. A butterfly pattern of blood spreads across the floor between them. I feel sick.

“I didn’t mean to, Lena. I just—I saw him on top of you and I grabbed a knife and I just…” Julian shakes his head. “It was an accident.”

“Julian.” I reach out and put my hands on his shoulders. “Look. You saved my life.”

He closes his eyes for one second, then opens them again.

“You saved my life,” I repeat. “Thank you.”

He seems about to say something. Instead he nods and shoulders the backpack. I reach forward impulsively and seize his hand. He doesn’t pull away, and I’m glad. I need him to steady me. I need him to help keep me on my feet.

“Time to run,” I say, and together we stumble out of the room and, finally, into the cool mustiness of the old tunnels, into the echoes, and the shadows, and the dark.

then

The temperature drops sharply on the way to the second encampment. Even when I sleep in the tents, I’m freezing. When it’s my turn to sleep outside, I often wake up with shards of ice webbed in my hair. Sarah is stoic, silent, and pale-faced.

Blue gets sick. The first day she wakes up sluggish. She has trouble keeping up, and at the end of our day of hiking, she falls asleep even before the fire is built, curling up on the ground like a small animal. Raven moves her into her tent. That night I wake to a muffled shouting. I sit up, startled. The night sky is clear, the stars razor-sharp and glittering. The air smells like snow.

There is rustling from Raven’s tent, some whimpering; the sound of whispered reassurances. Blue is having bad dreams.

The next morning, Blue comes down with a fever. There is no choice: She must walk anyway. The snow is coming, and we are still thirty miles from the second camp, and many more miles than that from the winter homestead.

She cries as she walks, stumbling more and more. We take turns carrying her—me, Raven, Hunter, Lu, and Grandpa. She is burning. Her arms around my neck are electric wires, pulsing with heat.

The next day, we reach the second encampment: an area of loose shale set underneath an old, half-tumbled-down brick wall, which forms a kind of barrier and shields us somewhat from the wind. We set to work digging up the food, pitching traps, and scavenging the area, which once must have been a decent-sized town, for canned goods and useful supplies. We’ll stay here for two days, possibly three, depending on how much we can find. Beyond the hooting of the owls and the rustling of nighttime creatures, we hear the distant sounds of rumbling trucks. We are less than ten miles from one of the inter-city highways.

It’s strange to think how close we have been to the valid places, established cities filled with food, clothing, medical supplies; and yet we may as well be in a different universe. The world is bifurcated now, folded cleanly in half like the pitched steep sides of a tent: the Valids and the Invalids live on different planes, in different dimensions.

Blue’s nighttime terrors get worse. Her cries are piercing; she babbles nonsense, a language of gibberish and dream-words. When it is time to start toward the third encampment—the clouds have moved in, heavy-knitted through the sky, and the light is the dull, dark gray of an imminent storm—she is almost unresponsive. Raven carries her that day; she won’t let anyone help, even though she, too, is weak, and often falls behind.

We walk in silence. We are weighed down by fear; it blankets us thickly, making it feel as though we are already walking through snow, because all of us know that Blue is going to die. Raven knows it too. She must.