Jack looked at me over his shoulder as I approached. He had the girl - the one who had called the cat and been bitten by an undead feline for her trouble - behind a locked steel gate at the bottom of a stairwell. She looked more sullen then afraid. "Hold on, Dekalb," Jack said. "I've got to see to her first."

I nodded and sat down on a crate. We were at the last safe barrier on the Seven Train Platform, according to a sign written in sharpie and taped to the wall. The tunnels themselves couldn't be closed off so the survivors had simply sealed off all the platforms, sticking to the concourses and their connecting passageways where they could be assured of their safety. Shailesh had told me that they had never actually seen one of the undead down on the tracks but that Jack refused to take the chance.

The girl - her nametag read HELLO MY NAME IS Carly - had been put out on the platform to see if she died or not. If she didn't, she could come back in. If she did Jack would put a bullet in her head. Either way he would be spending the night sitting next to her. He did what he could, passing a first aid kit through the bars. She dabbed mercurochrome on her arms until they turned bright orange.

"Did you forget what I taught you?" Jack asked in a flat voice. As if he was simply asking for basic data. "You never touch anything that's been outside. Not until it's cleared."

"It looked so scared and I just wanted..." Carly shrugged. "It's not like it matters. We're all going to die anyway."

"You can't give in to that attitude now. Especially not now, when we've actually got a chance to get out of here. You haven't heard about his boat?"

The girl stared at me. There was nothing but naked antipathy in her eyes, a complete refusal to connect with me. "Yeah? Well, thanks for making my death extra ironic, grandpa."

"You don't talk like that to your elders," Jack said. He didn't raise his voice but his tone made my skin crawl. "Are you listening to me?"

"Yes, sir. I just don't give a fuck, sir." She turned around and started walking away from the gate. "Enough of this," she shouted back. "I'm going to Brooklyn." Only a single fluorescent tube still burned out there and she was quickly swallowed up by shadows.

Jack didn't call after her. Instead he slumped down on the tiled floor, his back to a wall so he could keep an eye on the gate. He picked up his SPAS-12 again and laid it across his knees. Reaching into his pocket he took out a shell - a two and a half inch tungsten slug, unless I missed my guess.

"What are her chances?" I asked.

"About eighty-twenty, based on what I've seen. Talk to me, Dekalb. Tell me why you keep chasing after me while I'm just trying to do my job." The words were too open and vulnerable to belong to this man. He was clearly under immense stress. I thought about leaving him alone and coming back the next day but I had a feeling all of his days were like this.

"You sent out two people a couple of days ago. Paul and Kev, I think."

He nodded and pressed the magazine cut-off of his weapon and opened the slide. He snapped the slug into the barrel and closed it back up again. "Yes," he confirmed.

"So you're not trapped in here. You can send people out when you need to - to get supplies, say, or whatever. I'm not saying it isn't dangerous but it can be done. You must know some tricks to staying alive here that we don't."

Without moving his gaze away from the barred gate in front of him he raised the corners of his mouth. I wouldn't call it a smile. "Sure. We know one great trick. It's called desperation. When we get hungry enough somebody always volunteers to go out and get more food. Sometimes people just get bored and go up on their own. Some of them even come back. We're running short of everything, Dekalb. I don't know if you noticed but one resource we're low on is single men, eighteen to thirty-five. They're the ones who volunteer first."

"Wow," I said. I had thought there must be some secret.

"There's nothing to do down here but wait. Some people can't take that."

I understood, kind of. "I have an idea but it's dangerous. Very dangerous. We need to get your people to the river. There's an APC just west of Port Authority."

Jack nodded. "I've seen it. I've even thought of that myself. It would still run, assuming the fuel hasn't evaporated and the battery still has a charge and none of the belts in the engine have rotted away. Sure, we could back it up to one of the gates and load people onboard hassle-free. We'd have to make a bunch of trips but yeah, it would get us to your boat just fine."

Warming to the idea I pointed out the flaw. "Somebody would have to go out there, get it started, and drive it back here, though. If the engine didn't work on the first try they'd have to try to repair it. The dead would be on them the entire time. I have some soldiers I can bring in - Somalis - but they don't know how to maintain an American armored personnel carrier. I'm thinking that maybe you do."

"Correct."

Okay. We were getting somewhere. "There's just one hitch. None of this can happen until I complete my original mission." He looked over sharply and I held up my hands for patience. "Look, there are political issues. Somalia's in the hands of a warlord. I need a good reason to convince her to accept a bunch of white refugees who aren't soldiers, who are going to be a drain on her resources. We need to be realistic."

If I wanted to manipulate him that was the word to use. This was a man who had stripped himself of all pretense, all sentiment. Realism was his only philosophy. He nodded, once. I tried talking to him about what I needed to do and how he could help but he was done with that conversation. He just shut down, conserving energy maybe. He was the hardest man I ever met. It gave me hope, though. If anybody could get me to the UN building it was Jack.

We sat in silence for quite a while. I thought about heading back up to the concourse, to Ayaan and the other survivors but I just couldn't. I couldn't handle the way they looked at me - as if I was a tasteless joke, their fondest hope dangled before them after weeks and months of being told that nothing good could ever happen again. I couldn't face their weird games based on a popular culture that had ceased to exist.

The silence was just starting to really get to me - I was ready to start talking to myself, just to hear something - when it was broken by Carly. We couldn't see her, she stayed to the shadows but we heard her footsteps echoing on the deserted platform. Jack raised his shotgun to track the sound. That felt callous to me but then we both knew that she might be coming back changed.

"I threw up," she said from the darkness. "That's bad, right?"

"Probably. It might just be nerves." Jack rose slowly to his feet, the weapon still in his hands but not necessarily pointing at her anymore. "Come here. You're probably cold and hungry. I can help with that."

Ifiyah had been cold and hungry after she got bit. I wondered how many times Jack had sat this horrible vigil. Carly came up to the bars and we saw at once she was going to die. Her face was covered in a sheen of sweat and her eyes were completely bloodshot. Her arms, where the cat had scratched her, were puffy and dark with congested blood. Jack offered her a blanket and a can of chipped beef. She took them both without comment. I watched her face as she ate. The braces shredded the sensitive inner skin of her lips as she wolfed the food down. She noticed me staring and stopped for a second. "Get a good look, perv," she said. "I'm not going to get any prettier."

I looked away, flushing with embarrassment. I'd been thinking about Sarah, wondering if she was going to need an orthodontist soon. I couldn't very well explain that to Carly, though. She wouldn't have understood.

We sat with her all through the night. I dozed off now and again but I would always wake to find Jack sitting perfectly still. The shotgun never strayed from its position athwart his knees. Each time I looked Carly had taken another turn for the worse. She started panting, her lungs struggling to keep up with her body's demand for oxygen. Her fingers turned into painful-looking sausages, so thick the skin split around her nails and they bled dark blood. She started raving about four in the morning - begging for water and her mother and, more and more frequently, for meat.

Twice Jack offered to end her suffering but both times she refused without a moment's hesitation. "I think I'm feeling a little better," she said, the second time. Her breathing had, in fact, calmed down. Her eyes fluttered closed and I thought maybe she would actually make it - maybe her immune system would win this fight.

"Lay down if it's more comfortable," I told her. "Keep visualizing how much better you'll feel tomorrow. If you can sleep, you probably should."

She didn't respond to me. We waited a few minutes and then Jack kicked the steel gate, hard, with his boot. It clanged loud enough to hurt my ears but she didn't so much as wince. "Okay," he said. "I'm going to do it. Stand back."

I shook my head. "No. No, she's just tired - "

Slowly she stood up from where she'd been sitting on the tiles. Her legs were unsteady beneath her and her eyes were still closed.

"Look," I said, "she's okay." I knew I was wrong but I said it anyway. She came for us hard and with all the strength she had, smashing her bloated hands and her sweat-damp face against the bars, smashing her shoulders and her hips against the steel. The cartilage in her nose snapped as she collided face-first with the barrier, her cheekbone broke and her features smeared across her face. I did step back, then. Jack raised his SPAS-12 and fired, the slug entering her left eye and coming out the back of her head with part of her skull. She stopped moving, then. The shotgun clicked as the gas-powered mechanism automatically loaded another round. He didn't need it.

I was breathing hard and my body was buzzing with the chemistry of panic. Jack brought the weapon up to his chest and looked over at me. "Sometimes," he said, slowly, quietly, "I think they'd be better off if they all died in their sleep one night. Then they wouldn't be afraid any more. Some nights I stay awake and think about how to do it."

He shook off the thought and when he spoke again it was with his usual confident tone. "We'll commence with your mission tomorrow, after we've both had some sleep." Then he turned and headed up the stairs.