Billy thanked Vasiliy and told him he owed him one, and they went their separate ways at the door. Vasiliy was still puzzled though, and, after returning his kit and the dead rat to the back of his van, lit a Dominican corona and started walking. He went down the street and around to the cobblestone alley he had looked down upon from the girl’s window. Tribeca was the sole remaining neighborhood in Manhattan with any alleys left.

Vasiliy hadn’t gone more than a few steps before he saw his first rat. Skittering along the edge of a building, feeling its way around. He then saw another on the branch of a small, struggling tree grown up alongside a short brick wall. And a third, squatting in the stone gutter, drinking brown effluent flowing from some unseen garbage or sewage source.

As he stood there watching, rats started appearing out of the cobblestones. Literally, clawing up from between the worn-down stones, surfacing from the underground. Rats’ skeletons are collapsible, allowing them to squeeze through holes no larger than the size of their skulls, about three-quarters of an inch in width. They were coming up through the gaps in twos and threes, and quickly scattering. Using the twelve-by-three stones as a ruler, Vasiliy estimated that these rats ranged from eight to ten inches in body length, doubled by their tail. In other words, fully grown adults.

Two garbage bags near him were twitching and bulging, rats eating their way through their insides. A small rat tried to dart past him to a trash barrel, and Vasiliy kicked out with his work boot, punting the muncher back fifteen feet. It landed in the middle of the alley, not moving. Within seconds, the other rats were greedily upon it, long, yellow incisors biting through fur. The most effective and efficient way to exterminate rats is to remove the food source from their environment and then let them eat one another.

These rats were hungry, and they were on the run. Such daytime surface activity was practically unheard of. This kind of mass displacement only happened in the wake of an event such as an earthquake or a building collapse.

Or, occasionally, a large construction project.

Vasiliy continued another block south, crossing Barclay Street to where the city opened up to the sky above, a sixteen-acre job site.

He stepped up to one of the viewing platforms overlooking the location of the former World Trade Center. They were nearing completion of the deep underground basin meant to support the new construction, the cement and steel columns now starting to rise out of the ground. The site existed like a gouge in the city—like the gnaw in the little girl’s face.