"That one is too active," Ayaan said, scanning the wharf with her binoculars. The dead man in question wore nothing but a pair of tight jeans that overflowed with his bloated flesh. He clutched to a wooden piling with one arm while the other snatched at the air. His hungry face followed the boat as we steamed past.

On top of the wheelhouse Mariam called down for her Dragunov and one of the other girls passed it up. Mariam steadied herself against the Arawelo's radar dome and peered through the scope of the sniper rifle. I put my fingers in my ears a moment before she fired. The dead man on the pier spun around in a cloud of exploding brain matter and fell into the water.

Sixteen years old and Mariam was already an expert sniper. When did the girl soldiers have time to train?

Osman cleared his throat and I looked back at the map. "Here," I said, pointing at a blue letter H on the map, just a few blocks in from the Hudson. I looked up at the line of buildings on the shore and pointed at a spot between two of them. "St. Vincent Medical Center. They have an HIV care facility." I shrugged. "It's more dangerous because we'll be out of sight of the ship but it's my second best option."

The captain rubbed his face and nodded. He yelled at Yusuf to bring the ship in at an empty pier and the girls surged across the deck, shouldering their weapons and checking their actions. Osman and I struggled with a piece of corrugated tin ten feet long and just as wide that served the trawler in the place of a gangplank.

The engines whined and water churned as Yusuf brought us in to a bumping stop. The girls started jumping across even before we had the plank down - Commander Ifiyah at the fore, calling all her kumayo sisters to join her. They roared like lions as they raced to take up their assigned positions in two ranks of twelve on the wooden pier (Mariam was still up on the wheelhouse with her Dragunov). I shouldered my pack, shook Osman's hand, and picked my way carefully across the plank as if afraid I was going to fall in the water. I felt calm, far calmer than when we'd tried the East River. Ayaan had taught me a trick, to force myself to vomit before the battle so I wouldn't feel the need afterward. It hadn't been hard. The smell of death and decay rolling off Manhattan added to my general seasickness and left me feeling queasy ever since we'd spotted the Statue of Liberty.

The sounds of my footsteps on the pier echoed in the stillness. I moved to crouch behind Ayaan, who paid no attention to me whatsoever. She was so focused, so completely at peace in this madness. I lifted my own AK-47 and tried to copy her firing stance but I knew by the way the stock felt on my shoulder that I had it wrong.

"Xaaraan," she said softly but not to me. The word meant "ritually unclean", or more literally "improperly butchered meat." I'd never heard a more apropos description of the men and women who came at us then up the pier. Grotesque twisted faces on top of swollen bloody bodies that bent at unnatural angles - the hands reaching for us with fingers crooked like talons - the broken teeth - the rolling eyes - the silence of them.

"Diyaar!" Ifiyah screamed and the girls let loose, one rifle after another jumping upward with a cracking noise that left another corpse spinning down to smack the pier. I saw one get caught right in the teeth - enamel danced in the air. Another with shoulder-length hair clutched at his stomach but kept moving toward us, not running so much as flopping on uncertain feet, flopping toward us with an inexorability that terrified me. A woman in a jeans jacket and high black boots pushed past him and came right for me, the wind ruffling back her hair to show that both of her cheeks had been eaten away. Her jaw snapped in anticipation as she raised her arms to grapple me. A puff of smoke burst from her stomach and she fell back but others pushed to take her place.

"Madaxa!"Ifiyah ordered - shoot for the head. I saw a few of the younger girls shift their stance nervously and raise the barrels of their rifles a hair. They fired again and the dead fell away, dropping to the pier with a thud or spinning down to the water or falling backward into the crowd which just surged around them and came faster. Had they been waiting for us? There were so many - even with the noise we were making I couldn't imagine us drawing so many of them without warning. Unless maybe New York, the perennially crowded city, just had that many walking dead in it. If so we were doomed. It would be impossible to complete our mission.

"Iminka,"Ifiyah breathed. Now. In my horror I had barely noticed the most horrifying thing of all - that the dead were gaining on us. Only a few meters separated us from their oncoming tide. The girls didn't panic (though I know I did, hyperventilating and coming very close to shitting my pants). As one they adjusted their rifles with a ringing clack and opened up in full automatic.

If I had thought the carnage was bad before... I had no idea. I had seen assault rifles fired in full automatic before. In my job as a weapon inspector there had been plenty of times when some local chieftain or hetman wanted to impress me with the sight of his firepower. I'd never seen automatic assault weapons turned against Americans though. It didn't seem to matter if they were already dead. The line of them in front of me just exploded, their heads pulped, their necks and torsos torn to fibrous shreds. The ones behind them just shook and shook like they were seizing wildly as the bullets rattled around inside of them.

The noise of twenty-four Kalashnikovs rocking and rolling cannot be described so I won't try. It shakes you up, literally - the vibration makes your heart feel like its going to stop and can damage your internal organs with prolonged exposure.

When it was done we were standing before a pile of unmoving bodies. One woman in an I Love New York shirt with the sleeves ripped off struggled out from under the heap and came clawing at us but one of the girls - Fathia - just stepped forward and stabbed the dead woman in the head with her bayonet. The corpse went down. After that we all listened to the ringing in our ears for a while. We studied the shore end of the pier waiting for another wave but it didn't come.

"Nadiif," Ifiyah announced. The pier was clean. The girls visibly relaxed and shouldered their rifles. A few laughed boisterously and kicked at the slaughtered bodies on the wooden pier. Fathia and Ifiyah traded a high-five. All of the girls smiled - except Ayaan.

Her face hard she reached up and grabbed the muzzle break of my Kalashnikov. I winced, thinking she was intentionally burning herself for some reason - the AK-47 was notorious for overheating after prolonged firing - but then she pulled her hand away and showed me her unblemished palm.

"You did not discharge it," Ayaan said. The disgust in her face was withering.

It came to me that I hadn't fired my weapon at all, no. I had been too busy watching the girls. "I'm not a trained killer like you," I protested.

She shook her head bitterly. "Nor are you one of the xaaraan. So what does that make you?"

The girls spread out down the pier, Commander Ifiyah taking the van as they swept the shore for any sign of movement. Ayaan ran to her position in the front of the wedge. I turned and looked back at the Arawelo. Osman flashed me an "okay" sign with one hand. "You go after them now, Dekalb," he said, smiling broadly. "We'll stay here and guard the ship."