I circle around to the 10th Street side of the building. The rear entrance has been long boarded up. No cops necessary here. A trio of club kids walks loudly west. I wait for them to turn the corner, then I take three running steps, jump six feet straight up, grab a window ledge and clamber up the security screen that protects the broken glass behind it.

It takes me less than a minute using the window screens and bricks to scuttle up the wall to the roof of the school. The two pints I drank today have me peaked. I walk on the balls of my feet to the roof access door and inspect the lock. Old, rusted, I could force it easy. Instead I slip the picks from my back pocket. I wiggle the tension wrench into the lock then tease a hook past it and rake the pins. This keyed up, I can feel and hear each tiny click as I slide the remaining pins into place. I rotate the wrench, the lock pops open and I'm inside. Pitch dark. I leave the door ajar to admit the ambient light of New York City. My pupils grow to the size of dimes. It's not exactly clear as day, but I'll be fine.

The air is dank and thick with mold. Graffiti covers the walls. I hear a scamper of rat claws ahead of me, and then the rat freezes, sensing something large and dangerous. It's right, I am dangerous, but not to it. Animal blood may as well be salt water as far as the Vyrus is concerned.

I feel a slight shifting of the air. The door I've left open is drawing the warmer air up and out of the school. I follow the draft backward and find the stairwell. I descend three flights to the ground floor, sniffing at the thin trail of air wafting up past me, picking out details from the last twenty-four hours. I can smell the decay of the zombies, the urine of Ali Singh, the nameless blood and brains of the other boy. I can smell my own slightly feral scent and the Ivory soap I use in the shower. Fresher than the rest is a heavy overlay of sweaty cop, coffee and fingerprint powder, and the excited tang of news reporters. Under it all, the heavy, damp rot of the building.

I retrace my steps to the room where the killing took place. The door has no lock, but the cops have sealed it with the inevitable yellow tape, the era's icon for tragedy. I tear it off and open the door. It reeks inside.

Normally in these things someone would have been here by now with a bucket of bleach to get things sterile, but I guess the cops want to leave the crime scene intact until they have a confession out of Singh. Result: taped body outlines, dried blood, dried urine, dried vomit from whoever found the slaughterhouse, and oh yeah, dried brains.

I pick out the zombie smell from the others and walk slowly around the room separating the scent into three distinct strands. There's the girl's musky undertone, the rank underarm stink of the one whose neck I snapped, and the hair product used by the guy I stepped on. Now that I have the zombie smell isolated into the three individuals I know of, I sniff for any other signatures hiding in the mix. It's not there. No sign of another zombie, the carrier.

But the girl's musk.

Why musky? A stale musky sex scent. That's what I smelled on her last night before I got distracted by Singh. Zombies don't have sex, do they? Shit, I don't know. I walk over to where the taped shadow of her body is outlined on the floor and take a deep breath through my nose.

I filter out the other smells and focus on hers. The youth of her flesh. She was young, maybe seventeen, eighteen. The rot under the living flesh, brought on by the bacteria that was eating her alive, eating her dead. The acid smell of the cosmetics coloring her eyes and mouth and nails midnight black. The compost odor when her bladder and bowels released after I stabbed her in the neck. Perfume, sweat, a fungus in her Doc Martens. All that, and a sweaty musk. Someone rubbed against her, touched her. Someone fucked her. Not today, but recently, since she was infected. I try to imagine the sicko that would have sex with one of these things while it pawed at him and tried to take a bite out of his brain, the bastard that would mate with the bacteria inside this dead girl.

I take one more deep breath to fix the musk smell in my mind so that I can pick it out when I find it again. That's when I notice something is missing. I take another whiff, and I catch it. An absence. Throughout the room, little patches of nothing in the matrix of odors. Slight erasures sprinkled across the air where something has absented itself from the catalogue of the room's history. I close my eyes. I inhale and try to capture one of the absences, to trace it step-by-step across the room and re-create what this thing might have done here.

And it is this deep level of concentration that allows someone to sneak up behind me and hit me on the back of the head with a somewhat immature whale.

The sound of bickering wakes me and tells me exactly where I am. I peel an eye open for confirmation, and sure enough, here I am in the squalid tenement basement headquarters of the Society. I'm on a dingy cot in an alcove. In the middle of the room three people are standing around a rickety card table under a single bare lightbulb. The two guys doing the bickering are Tom Nolan and Terry Bird.

Tom reads about twenty-five, but carries a few more actual years. He's got the blond dreads and washed-out clothes of the downtown radical, along with the requisite number of piercings and tattoos. Terry is older looking, say fifty or so. His style is more old school: ponytail, beard, John Lennon glasses, Earth Day T-shirt and Birkenstocks; that kind of thing. The third is Lydia Miles. Call her twenty, short dark hair, leather pants, white tank top, bodybuilder muscles, and an upside-down pink triangle tattooed on her shoulder. Just another ragtag band of East Village radical-socialist-anarchist-revolutionaries hanging out and plotting the overthrow of The Man. Of course this band of revolutionaries also drinks blood.

Lydia stands there watching while Tom goes at Terry and Terry pulls a passive-aggressive mellow hippie thing in response. Guess who's the topic of discussion?

– I'm telling you he's working for the fucking Coalition. Why else would he be there?

– Well, Tom, that may be. But to me, the real question here, and I think Lydia may agree with me, is what were you doing there? I was under the belief that we had agreed.

– Fuck your agreement. You agreed, I didn't agree to shit. This creep is hip-deep in the Coalition. He's their ratfink spy down here and now they have him, they intentionally have him causing trouble on our territory. He's a saboteur, he's a fucking saboteur and we should execute him right now.

Terry pushes his slipping glasses back up his nose.

– Well I, for one, certainly think that would be more than extreme. Even, for the sake of argument, even if it came to the point where we might execute him, I think our first step should be to question him.

– Fucking fine, let's interrogate him then. Let's wake his ass up and teach him a lesson about the revolution.

He picks up a short length of pipe from the card table. Lydia is looking right at me. She's staring me in the eyes just as she has been since right after I opened them. She smiles and turns to the boys.

– He's awake.

They both turn to look at me sprawled on the cot. Tom takes a quick step in my direction, the piece of pipe still in his hand.

– OK, fucker.

Terry reaches out and lays a hand on Tom's shoulder.

– Easy, Tom, just mellow out a little, guy.

Tom stops and squeezes his eyes shut. He turns to Terry as if he'd like to wrap the pipe around his head instead of mine.

– How many times do I have to tell you? How many, man? Don't tell me to mellow out. You be as mellow as you want, but don't tell me what to do.

Terry smiles.

– Sure, Tom, no prob. I'm not trying to disrespect you. I just want us all to calm down a little here and find some things out before we think about resorting to violence. There are always options, man, we just need to explore them.