Fanning out across the street the girls threw hand signals at one another. The barrels of their Kalashnikovs swept the street corners, the recessed doorways, the hundreds of cars abandoned on the cobble stones. I had expected - well, I guess I had hoped - that the roads would be clear. We could have commandeered some transport and driven to the hospital.

Not a chance. In the panic of the Epidemic the usual Manhattan gridlock must have turned into a death trap. There were cars everywhere, many of them dented or damaged. They lined every side-street we passed, crowded every intersection. I saw a Hummer 2 up on the sidewalk, its shiny front bumper wedged permanently between a mailbox and the broken wood front of a deserted bistro. On the other side of the street Fathia clambered up on top of a taxi with four flat tires and scanned the road ahead with her rifle at her eye.

"This way," I told Ifiyah and she gestured for her troops to follow us. I led her down a short block of Horatio street, past a gas station with shuttered windows. Paper signs had been wrapped around the pumps and secured with duct tape: "NO GAS, NO MONEY, NO EMPLOYEE. GOD BLESS YOU." Around the corner was a storefront psychic (the garish neon tubes visible in the window were dead now) and a little boutique that must have sold women's clothing. The front window showed three cheerily dressed mannequins and a bunch of billowing green cloth.

Ayaan stopped in front of the window and peered inside.

"Thinking of a new look for summer?" I asked, wanting her to hurry up. It was understandable, of course - Ayaan had probably never seen real women's fashions before. She had spent most of her life in a uniform and the lure of Western dress must -

"I saw movement in there," she insisted.

Oh.

The soldiers pressed in, some of them walking backwards with their rifles facing out as others lead them with a hand on their shoulders. Their discipline was heartening. In another life I might have found it creepy, the way these girls worked together but now it meant I might survive this ludicrous mission.

Without warning a dead woman pushed through the folds of green in the window and slammed up against the glass from the inside. She was willowy and blonde with thin refined features. Her face was pockmarked only here and there with tiny sores that looked almost like sequins. She wore a flowing maroon sleeveless dress and for a heartbeat we were all transfixed by the sight of her elegance.

Then her thin arms came up and her tiny fists started bashing at the glass. Her face thrust forward and her jaw opened against the window as if she were trying to chew her way through it with her yellow teeth. The black hole of her mouth made a perfect seal on the glass as she hungered for us.

Fathia raised her rifle but I shook my head. "That's tempered glass - shatterproof. She'll never get through it. If you shoot now the noise might draw others, though."

The soldier looked to her commander. Ifiyah nodded once and we moved on, leaving the dead woman behind us. After we turned the block we couldn't even hear the muffled thuds of her fists on the window.

In the broader expanse of Greenwich Avenue we found a water truck still dripping from a splatter of gunshot holes and an incredibly long streamer of yellow police tape flapping in the breeze. I grabbed a handful and read "QUARANTINE AREA: TRESSPASSERS WILL BE MET WITH LETHAL FORCE" before letting it flutter away. We made a left on Twelfth and the girls spread out rapidly. We had arrived. Ifiyah called for her troops to establish fire zones and to designate a CCP - a Casualty Collection Point - where they would meet up if they got separated. I lead Ayaan up to the closed Emergency Room doors of St. Vincent and peered inside.

"It's dark in there," I said. Well, of course it was. Did I expect the power to be on six months after the end of the world? "I don't like it."

"It is not for you to decide," Ayaan said but there was less anger in her voice than usual. She slipped her thin fingers into the crack between the two automatic doors and tugged. They moved an inch and then slipped back. Looking over at Ifiyah she held up three fingers and we were quickly joined by a trio of sixteen year olds. Between the five of us we pried the doors open wide enough for me to fit through.

Ayaan handed me a flashlight from her dambiil bag and checked her own by switching it on and off rapidly. The three girls who had joined us ran through the same procedure. I glanced at Ifiyah for authorization to begin and then stepped inside. The lobby of the emergency room was a mess of overturned chairs and blank-screened television sets but at least a little light came in the glass doors and cut through the gloom.

The admissions desk was half buried under a slurry of glossy pamphlets against heart disease and second hand smoke. I stepped on them being careful not to slip and found a photocopied directory taped to the wall. "This way," I said, pointing at a pair of swinging doors leading off the main lobby. The HIV clinic was deep inside the building. It might take us ten minutes to get there in the dark and just as long to get back. Ifiyah had given us ninety minutes to complete the mission and exfiltrate back to the boat.

I only had to do this once, I told myself. Just once and then I can go see Sarah. The thought of my seven year old daughter languishing in a Somalian religious school made my heart rattle in my suddenly airless chest.

I kicked open the double doors and flashed my light down pitch darkness of the corridor beyond. The cone of illumination caught a couple hospital beds pushed up against the wall. A heap of stained linen on the floor. Two rows of doors, dozens of them, that could be hiding anything.

"Let's get this over with," I said. Ayaan pursed her lips as if rankled at being given an order by a civilian. She lifted her rifle to her shoulder, though, and stepped into the hallway.