A few seconds later the bats suddenly stopped attacking the people on the platform. They fluttered around for a moment, circling just under the ceiling like leaves in an eddy. Then they darted back over the tracks and took off down the tunnel, following the inky shape.

While the dispatcher put out a call, Meg broke the rules. Pulling a first aid kit from under the counter, she left her booth and hopped the turnstile. She turned back long enough to tell new arrivals not to come in, then went to help the riders who had fallen.

Two patrolmen from the sixth precinct arrived moments later. While one of them called for an ambulance from St. Vincent’s and kept other people from entering the station, the second officer went to help Meg.

She was extremely calm as she applied disinfectant and bandages to the students’ scratches and told the officer about the bats and about the well-dressed man who must have fallen from the platform. What she saw, she decided, had been his jacket flying up. Or maybe it was the reflection of her own dark hair on the glass of the booth.

The officer went to the end of the platform to have a look. He hopped down onto the tracks. When he came back he was holding headphones from a Walkman. The foam ends were wet with blood.

He called for backup from the transit police and recommended that the station be closed.

Still calm, Meg went back to her booth and called her supervisor for instructions. He told her to lock the money drawer and the booth and to do whatever the police told her.

Transit police arrived. They took Meg’s name, address, and phone number, and told her she could go.

She took the next bus back to Queens.

The American Museum of Natural History was built in 1874. Located along Central Park West between Seventy-seventh and Eighty-first streets, it is best known today for its unparalleled collection of prehistoric fossils and dinosaur skeletons. However, it was originally designed to be a showcase for contemporary nature and archaeological displays.The dioramas of modern-day animal life, from birds to bison to fish, remain among its most popular attractions.

But the galleries and spacious display halls are not the museum’s only service. Research, exploration, and education are also important functions, and the fifth floor of the museum-closed to the public-has long been a haven for scientists and scholars. There, in hundred-year-old cabinets and drawers as well as in modern cryogenic chambers, the museum stores countless animal, vegetal, and fossil specimens for study.

Given what had happened in the tunnel, Gentry was in as good a mood as he could be. He was guardedly optimistic for a reconciliation. He liked Nancy Joyce, he admired her courage and determination, and he felt bad about what he’d done. He didn’t feel repentant, for he’d do it again. Just bad. And all he wanted was the chance, at some point, to tell her everything-except the fact that he wouldn’t have done anything differently.

Gentry got off the elevator at the fifth floor. A skinny young man was passing. The kid held a small plastic tray full of tiny bones, stringy sinew, and what looked like blood. The detective asked him for directions to Professor Lowery’s laboratory. The young man pointed ahead and told him to hang a left and then a right.

Gentry thanked him then looked at the dish. “Mind if I ask what that is?” he asked.

“Lunch,” the young man replied. “Chicken cacciatore.”

The man continued down the corridor. Gentry followed him. There were framed portraits and photographs of various expeditions, going back to the Gobi expedition in the 1920s. The men and women portrayed reeked of scholarship and trailblazing. The detective made a point of not looking at them. He didn’t want to start feeling inadequate between here and the laboratory.

Gentry had never been at ease in academic settings. He spent one semester at City College before bagging it for the NYPD. He liked finding things out for himself, not being lectured to. That was one of the many things he loved about his typesetter father. The man never talked at him. He talked to him and with him, as though it were always man-to-man. Even when it was man-to-seven-year-old.

Part of Gentry’s discomfort also probably had to do with his mother having worked as a secretary for an intellectual snob of a college dean, Dr. Horst Acker. “Boss Tweed,” he and his dad used to call him. His mother ended up leaving Gentry’s father for him. The seven-year-old Gentry hated the red-cheeked, pipe-smoking creep with all the energy in his body, and after three months he ran away from his mother to live with his dad. His mother let him go, which was fine: Gentry wasn’t crazy about her, either.

Before Gentry reached the laboratory, his beeper sounded again. He checked the number; this time it was Chris Henry. Give that dog a bone and there was no one who could chew it up faster. He kept walking.

At Lowery’s laboratory, Gentry rapped on the frosted glass. His heart was thumping hard, harder than when he went into the hole in the service tunnel. He heard a Swiss-sounding voice and saw Joyce’s shadow move toward the door. She hesitated a moment, then turned and opened it.

“Hi there,” he said.

“Come in,” she replied. There was a hint of distance in her voice, in the set of her mouth. But there was curiosity in her eyes, and Gentry latched onto it.

Gentry entered a room that was about three times the size of his office at the police station. Joyce walked the door shut so it wouldn’t slam. Gentry glanced to the right. Along the wall was a wide black table. It was roughly half as wide and fully as long as a pool table, and it sat under a series of low, bright lights. A tall, elderly man in a white lab coat was bent over it, his back to Gentry. The man didn’t turn when the detective entered.

“We’ve been working on the mold from the gouge in the deer bone,” Joyce said. “We were waiting for a specimen to come up from storage. Now that it’s here we’re just finishing the scans.”

“I see. I got paged on the way over. Is there a phone I can use?”

“Over here,” she said, pointing to a desk.

The phone was nestled between a stuffed and mounted gerbil and chipmunk. Gentry called Ari first. The line was busy. Then he called the crime lab. Chris Henry came on and said he’d just finished measuring the trauma. He rattled off the dimensions and Gentry wrote them down. When Henry hung up, Gentry handed the page to Joyce.

“What’s this?”

“The lab results I said I was waiting for. Fourteen of the bodies I found in the subway belonged to homeless people. They were pretty torn up. But not as badly as a fifteenth. That one belonged to a bicyclist who disappeared from way up on Riverside Drive early this morning.”

“The one who had the strange bites.”

“Right,” Gentry said. “And two things I didn’t tell you: She was gutted, just like the deer. And there were large, bloody hatch marks on the grate overhead.”

Joyce’s expression darkened.

Gentry pointed to the paper. “These are the dimensions of marks that were found on a rib belonging to the bicyclist.”

Joyce read them. “They’re the same as the deer,” she said. “Professor?”

“I heard,” he said. He still didn’t turn. “Are you certain of their accuracy, Mr. Gentry?”

“It’s Detective Gentry, and absolutely.”

“Then input them, please, Nannie.”

Joyce nodded and sat down at her computer. As she typed, Gentry walked over to the lab table. In the back of the room, to Gentry’s left, was an industrial-size sink. Bookcases and shelves covered every other free foot of wall space. Books, magazines, papers, jars with floating things, and other taxidermic specimens were jammed into every available space. The room smelled faintly of mildew and formaldehyde.