I lean up against one of the doors in front of me. It moves freely, and I shove it open and walk into what must have been the gas chamber. The dark hides the details of what I know is all around me. There are bodies here. I have no idea how many, but I can see their shapes stacked up in featureless piles. The cavernous room is filled with the buzzing of thousands of flies gorging on dead flesh, and I keep looking up to avoid looking down. There’s a hole in the roof three-quarters of the way down the length of the room, and I can just about make out metal gantries and walkways high up on either side. Wide-gauge pipework weaves in and out of the walls of the building, and an enormous exhaust fan has been mounted at the far end of the room, its blades still turning slowly in the gentle evening breeze.

“Let’s get out,” Adam whispers from somewhere close behind me. “Fucking stinks in here.”

I move forward again, dragging my feet along the ground so I don’t trip over anything I can’t see, convinced that the entire floor is covered with gore and bits of bodies. I kick bits of wood and twisted chunks of metal out of the way-remnants of the fallen section of roof-and finally reach the far wall, my pace almost as slow as Adam’s. I work my way along, trying to find a way out. In the farthest corner, hidden from view by another unidentifiable pile of rubbish, is a wide door that’s hanging off its hinges, half open. I duck underneath it, then turn back and prop it open fully so Adam can get through. His uneven footsteps and grunts and moans of effort make him sound like a monster in the shadows.

“We can’t stay here,” he says.

“Might be some other buildings around.”

As soon as he’s completely outside, I put my arm around him and support his weight. We’ve only taken a few steps when he stops.

“Fuck me,” he mumbles. “Would you look at that…”

At the side of the long, narrow building is another clearing, out of sight until now, and the ground is almost completely covered with bodies for as far as I can see. There are hundreds of them, thousands probably, stacked up in massive piles. I leave Adam again and move toward the nearest one. From a distance the gloom makes it look like a single, unidentifiable mass, only distinguishable as human remains because of the countless hands, arms, and legs that stick out from it at awkward angles. As I get closer, however, a level of sickening detail is revealed. These bodies have been dumped-not even laid out-and those at the bottom have been crushed by the weight of the rest, leaving them unnaturally thin, almost like they’ve been vacuum-packed. Higher up, countless squashed, frozen, waxy faces stare back at me unblinking. Their discolored flesh, hollow cheeks, and sunken eyes give each of them grotesque, nightmarish, masklike expressions. Seeing them makes me think about my own mortality. I don’t feel anything for any of the people here-they’re just empty shells now, each of them a spent force-but I swear I won’t end up like this.

“Look on the bright side,” Adam shouts across the clearing.

“There’s a bright side?”

“’Course there is. You got away. That could have been you, that could. Could have been me…”

I ignore him and keep walking farther into the clearing, following a narrow pathway between another two fifty-yard-or-so-long piles of death. Distracted, I lose my footing when I reach the end of the rows, and the ground suddenly starts to crumble beneath my boots. I fall back and find myself sitting on my backside on the edge of a vast hole, at least twenty yards square and deep enough for me not to be able to see the bottom in some parts. I know immediately what it is-a mass grave filled with an incalculable number of people like Adam and me. I get up and carefully walk around the edge. There’s a bulldozer up ahead with a massive metal scoop. At first I think they must have used it to dig the pit, but then I see there’s a scrap of clothing caught on the teeth of the scoop and I realize they were using it to fill it. Directly below me there are corpses reaching almost all the way up to the surface, piled up where they were tipped out. They look like they’re climbing over each other to get out.

I jog back over to Adam, forcing myself to look away from the dead. How many sites like this were there, and are any still in operation? Even now as I’m wasting time here, are more of our people being killed elsewhere? Then another thought crosses my mind that makes me go cold: my daughter, Ellis. Did she end up in a place like this? Is she there now, waiting to die? Is she here? For a few desperate seconds I turn back toward the corpses and start looking through them, terrified the next face I see will be my little girl’s. Then, as quickly as sudden panic just took hold, common sense takes over again. If she’s here there’s nothing I can do. I have to believe she’s still alive. She’s all I’ve got left.

“So where are they all?” Adam asks.

“Who?”

“The fuckers who did this. Where’d they go?”

“I don’t know,” I answer as I lead him out behind the main building toward a group of three square-shaped, light-colored, prefabricated huts that look new in comparison to everything else. “Just abandoned the place, I guess. Maybe they were attacked?”

“Hope the bastards got what they deserved.”

Two of the almost identical shedlike buildings are locked. The corrugated metal roller door on the front of the third, however, is not. I open it fully and go inside. It’s small, cramped, and half full of bags of chemicals. Doesn’t matter. It’ll do for tonight. No one with any sense will come here, and even if they do, we’ll just play dead. I’d have fought side by side with any of the thousands of people who died here, but they’re just rotting meat now, and we’ll use them as cover.

Adam sits down on a pile of sacks, struggling to get comfortable and still talking nonstop about nothing of any importance. I close the door, then find myself a scrap of space in the far corner of the hard concrete floor and try to sleep, resting my head on another plastic sack full of Christ-knows-what. It could be poisonous or corrosive, but it doesn’t matter. I cover it with my coat and close my eyes, too tired to care.

I’M WOKEN BY A crash and a muffled cry of pain. I sit up quickly and look around the dark room, struggling for a second to decide where I am. The combination of the acrid chemical smell and the stench of decay helps me remember. Where’s Adam? I catch a momentary glimpse of him outside through the open door, hobbling back toward the main building. I grab a knife from my backpack and run after him. I’ve barely taken two steps out of the chemical storeroom when I hear other voices up ahead. There are people around the front of the cull site. I drag Adam out of the way, stopping only when we’re both pressed up tight against the outside wall at the back of the main killing chamber.

“It’s Unchanged,” he whispers, voice full of nervous excitement. “I saw them.”

“How many?”

“Don’t know. Heard engines.”

What the hell do I do now? Despite what Adam probably thinks, we can’t risk taking them on until we know how many we’re facing. There could be hundreds of them here, and if they’ve dared come out into the open like this then they’re probably armed to the teeth and ready to fight. What do they want? Maybe they’ve come to try to get this place restarted? Shit, maybe they’re here looking for us?

“Wait here,” I tell him, pushing him toward an alcove. “Keep yourself under control and don’t do anything until I come back, okay? I’ll try to get a better look.”

Adam nods and does as I say. I take a couple of steps away from the building and see that there’s a metal ladder running from ground level to an access hatch up high. Before I can talk myself out of it I start climbing, trying to limit the sound of my heavy boots on the metal rungs. I pause when I’m two-thirds up and lean over to one side to peer in through a grubby window. The early morning sun is blazing through the windows along one side of the slaughterhouse and the hole in the roof, filling it with light, uncovering every gruesome detail that was hidden in the darkness last night. The Unchanged are inside the building now. I can see a couple of them slowly picking their way through the bodies and debris.