Gentry stopped beside the professor. Kane Lowery had a long, priestly soft, white face, eyes the color of gunmetal, and thinning, slicked-back gray hair. There were three square aluminum pans lined up in front of him. The pan on the left contained what was obviously the cast of the wounds made from the deer bone. The second pan had a small dead bat about six inches from wingtip to wingtip. Lowery was holding a large, humming penlike instrument directly above the second pan; a cable ran from the back end to the computer, and he was moving a laser beam slowly from left to right.

The professor cleared his throat.

“Robert,” Joyce said.

He looked back. She crooked a finger and motioned him over.

Gentry turned from Professor Lowery. He was annoyed by that little cough signal between them, and he was a little disappointed in Nancy. For someone who just complained that she hadn’t been treated like a professional, she’d been quick enough to help tug on Gentry’s leash.

But he could live with that. He wasn’t here to make friends with Professor Lowery. And unlike Nancy, he didn’t have to work with the man.

Gentry stopped beside her. “What exactly is the professor doing?”

“He’s using a laser to take very precise measurements of the bat’s teeth.” She pointed to the computer monitor. “The numbers in the left column are the dimensions of the wound in the deer bone. When the professor is finished, the column on the right will have the figures for the dentation of a little brown bat, like the ones that attacked at the field last night. If necessary, we’ll also check the bat’s claws and-”

“Explain it later, Nannie,” the professor interrupted. “I’m just finishing the conic scan.”

“I see,” she said. “The data is coming up now,” Joyce said. She read the new figures as they appeared. “The tangent angle at the bottom of the teeth is forty-two degrees.”

“And it’s forty-six on top,” the professor said.

“That’s correct. One point zero seven inches apart.”

“Which gives us-?”

Nancy looked at the first column of figures. “The proportions are an exact match.” Her eyes shifted to the figures Chris Henry had given to Gentry. “My God,” she said.

“What?” Lowery said.

“They’re all a match, all three sets of teeth.”

The professor put down the laser. He turned and slipped his large hands into the pocket of his lab coat. “Incisors with a distinctive medial separation. The hint of a W-shaped impression from the molar cusps and ridges.”

“It’s unbelievable,” Joyce said.

“But undeniable,” Lowery responded.

“What is?” Gentry asked.

“The deer in Westchester was attacked and partly consumed by a giant predator,” the professor said. “So, apparently, was your bicycle woman. And judging by the dentition, it appears in both cases to have been a bat. More precisely, a member of the family Vespertilionidae.” The professor smiled for the first time. “This is amazing. And the simulated reconstruction we did earlier of the formation of the guano mound in the tunnel also supports the theory-well, it’s more than a theory now, isn’t it?-that there is a very large vespertilionid specimen in the tunnels under the city. Possibly the same creature, or a second one.”

“I just can’t believe it,” Joyce said. “There’s got to be another explanation.”

“Such as?” Lowery asked. “A bear or mountain lion? That is more believable?”

“In a way,” Joyce said.

“And did the lion also leave the guano? Did it shatter the tree limbs? Could it carry a grown woman seventy or eighty blocks, through city streets and subways, without being seen?”

Joyce just shook her head slowly. “I don’t know, Professor. I don’t know what to think.”

“You’re talking about agiant bat,” Gentry said.

“It appears so, Mr. Gentry,” Lowery said.

“This has to be some kind of sick joke. Where would it have come from?”

“I honestly don’t know,” Lowery said. “But for someone to execute a ‘sick joke’ with this kind of precision would take some doing. Why bother?”

“The same reason that people fake UFO abductions and Loch Ness monster sightings. Publicity.”

“Are you so convinced that all of them are fake?”Lowery asked.

The three of them stood still. The only noise was the whirr of the computer hard drive backing up the data and the sound of the elevator opening and closing behind the laboratory. Joyce and Lowery were looking at each other, almost like predator and prey. The professor’s arms were crossed, his brow hawklike. He seemed to be waiting for her to challenge the findings so he could slap her down with a fact.

Gentry decided he’d take the hit. “Assuming you’re right about this, exactly how big is ‘giant’?”

“That we don’t know.”

“Can’t you just calculate up from-”

“No,” Lowery interrupted impatiently. “That wouldn’t work.”

“Why not?”

Joyce explained, “The larger the bat’s torso, head, and legs are, the greater the lift required from the animal’s wings. But if you make the wings larger, then the muscles needed to control the wings must also be bigger and stronger. Increase the size of those muscles, and the wings must be larger still to lift that additional weight. Do you follow?”

“Some of it,” Gentry said.

“If the bat is a vesper,” Lowery said, thinking aloud, “then the musculature Nannie just described would make it a seriously deformed specimen. Almost like a flying bull.”

“Why?” Gentry asked. “Aren’t there some pretty big nondeformed birds?”

“There are,” Joyce agreed. “But birds have an entirely different anatomy from bats. A bird’s feathers provide a great deal of lift, and they have just two opposing flight muscles. Bats have three pairs of pectoral muscles for the downstroke and a complex series of small back muscles for the upstroke. Bats don’t so much flap as move through a rapid series of wing-beat cycles. So there would be a significant weight difference between, say, an albatross with a wingspan of twelve feet and a bat of the same size.”

“All right,” Gentry said. “I think I understand that. So how about this. Can’t you figure out how big this hypothetical bat would have to be to lift a deer into a tree or fly carrying a dead body from somewhere around Riverside Drive to a subway tunnel under Forty-fifth Street?”

“Unfortunately,” Joyce said, “that doesn’t help us much either. As the professor said, we could be dealing with more than one big bat.”

“I did not say they’d be flying in tandem,” Lowery pointed out. “The air currents from one would almost certainly upset the other.”

“Well, you two can discuss all this later,” Gentry said. “The question I need answered is if there is a big bat, do you think it’ll want to stay here or is it just passing through?”

Joyce said she didn’t know. Lowery didn’t say anything. Gentry exhaled loudly.

“What puzzles me about all of this,” Lowery said after a moment, “is if there is such a creature, how it came to be. And why the smaller bats seem to congregate around it. And how it’s managed to remain hidden until now.”

“Maybe it hasn’t been hidden,” Gentry said.

Lowery looked at him. “Explain, please.”

“Earlier this morning I checked through New York state police reports of bat attacks over the last few days. In addition to the incident up in Westchester, there were two attacks by groups of small bats. They follow the Hudson River down from Albany. When I get back to the station house I can look back farther. There may be more.”

“By all means do so,” Lowery said.

Gentry definitely didn’t like the man’s manner. He turned toward Nancy. It was time to take a try-calling-Ari-again break.

“Can I use your phone again?” he asked Nancy.

She nodded.

Gentry walked to the desk and dialed. Captain Moreaux answered. “Ari, it’s Gentry.”

“Robert,” Moreaux said, “I thought you’d want to know we’ve had another attack.”