“She was in here taking a nap,” said Billy. “Woke up feeling something gnawing on her lip. The thing was up on her pillow, Vaz. A rat in her bed. Kid won’t sleep for a month. You ever heard of this?”

Vasiliy shook his head. There were rats in and around every building in Manhattan—no matter what landlords say or tenants think—but they didn’t like to make their presence known, especially in the middle of the day. Rat attacks generally involve children, most often around the mouth, because that’s where the food smell is. Norway rats—Rattus norvegicus, city rats—have a highly defined sense of smell and taste. Their front incisors are long and sharp, stronger than aluminum, copper, lead, and iron. Gnawing rats are responsible for one-quarter of all electric-cable breaks in the city, and the likely culprit behind the same percentage of fires of unknown origin. Their teeth are comparable in pure hardness to steel, and the alligator-like structure of their jaw allows for thousands of pounds of biting pressure. They can chew through cement and even stone.

Vasiliy said, “Did she see the rat?”

“She didn’t know what it was. She screamed and flailed and it ran off. The emergency room told them it was a rat.”

Vasiliy went to the window that was open a few inches to let in a breeze. He pushed it open farther and looked down three stories to a narrow cobblestone alley. The fire escape was ten or twelve feet from the window, but the centuries-old brick facing was uneven and craggy. People think of rats as squat and waddling, when in fact they move with squirrel-like agility. Especially when motivated by food or by fear.

Vasiliy pulled the girl’s bed away from the wall and shed its bedding. He moved a dollhouse, a bureau, and a bookcase in order to look behind them, but he did not expect to find the rat still in the bedroom. He was merely eliminating the obvious.

He stepped out into the hallway, pulling his wheeled cart along the smooth, varnished wood. Rats have poor eyesight and move largely by feel. They get about quickly by repetition, wearing paths along low walls, rarely traveling more than sixty feet from their nest. They don’t trust unfamiliar settings. This rat would have found the door and turned the corner, hugging the right-hand wall, his coarse fur gliding against the floorboard. The next open door led into a bathroom, the young daughter’s own, decorated with a strawberry-shaped bath mat, a pale pink shower curtain, and a basket of bath bubbles and toys. Vasiliy scanned the room for hiding places, then sniffed the air. He nodded to Billy, who then closed the door on him.