Mayhew bounded off with his bouncy Reebok stride. Gamay flipped open her cell phone, to let Paul know she had arrived, only to remember that Dooley said the only place with service was the water tower.

She followed a crushed-shell pathway past a row of neat cabins to the foot of the tower. After climbing to a platform at the top, she got a signal, but then she hesitated. Paul was most likely in a seminar, and she didn’t dare interrupt him again. She tucked the phone in her pocket.

She took in the view from the tower. The long, narrow island was shaped like a deformed pear. It was one of a group of mangrove islands whose rough texture looked like scatter rugs when seen from the air.

Gamay climbed down from the tower, working up a good sweat in the humidity with little exertion, and walked until she came to a tangle of mangroves where the trail ended. Turning around, she explored the island’s network of trails before returning to her room. After a refreshing catnap, she took a shower, and was patting her body dry when she heard laughter. Happy hour had started.

Slipping into white shorts and a pale green cotton blouse that complemented her dark red hair, now twisted up on the back of her head, she made her way to the Dollar Bar. About a dozen people in lab coats were sitting at the bar or around tables. The conversation came to a near stop as she entered, like a scene in an old Western where the gunslinger pushes through the swinging doors into the saloon.

Dr. Mayhew got up from a corner table, came over to the bar, and greeted Gamay with his quick smile.

“What can I get you to drink, Dr. Trout?” he asked.

“A Gibson would be fine,” she replied.

“Straight up or on the rocks?”

“Straight up, please.”

Mayhew relayed the order to the bartender, a well-muscled young man with a military-style brush cut. He shook the gin, poured, and put three onions on a toothpick, making it a Gibson martini instead of a martini with olives.

Mayhew guided Gamay and her drink back to a corner table. Pulling out a chair, he introduced her to the four people seated around the table, explaining that they were all part of the center’s development team.

The lone female at the table had short hair, and her pretty face was more boyish than feminine. Dory Bennett introduced herself, and said she was a toxicologist. She was drinking a tall mai tai.

“What brings you to the Island of Dr. Moreau?” asked the woman.

“I heard about this wonderful bar.” Gamay glanced around at the practically bare walls, and with a straight face added, “It seems that a dollar doesn’t go as far as it used to.”

There was a ripple of laughter around the table.

“Ah, a woman scientist with a sense of humor,” said Isaac Klein, a chemist.

“Dr. Klein, are you saying I don’t have a sense of humor?” Dr. Bennett asked. “I find your scientific papers very funny.”

The good-natured ribbing drew another round of laughter.

Dr. Mayhew said, “Dr. Bennett forgot to mention that the center’s assistant director is a woman as well: Lois Mitchell.”

“Will I get to meet her?” Gamay asked.

“Not until she gets back from-” Dr. Bennett caught herself midsentence. “She’s away . . . in the field.”

“Lois is working with Dr. Kane,” Mayhew said. “When she’s here, the island is not as male dominated as might appear at first glance.”

Gamay pretended she hadn’t seen Mayhew gently nudge Bennett’s arm and looked around at the other tables in the room.

“Is this the lab’s entire staff?” she asked.

“This is a skeleton crew,” Mayhew said. “Most of our colleagues are working in the field.”

“It must be a very large field,” she said in a lame attempt at humor.

There was deafening silence.

Finally, Mayhew showed his teeth.

“Yes, I suppose it is,” he said.

He glanced around at the others, who took his comment as a signal to force grins on their faces.

Gamay had the feeling that they were all connected to one another with wires and that Mayhew had the switch in his hand.

“I met another woman on the dock,” she said. “I believe her name was Dr. Lee.”

“Oh, yes, Dr. Song Lee,” Mayhew said. “I didn’t count her because she’s a visiting scientist and not regular staff. She’s extremely shy, and even dines in her cabin by herself.”

Chuck Hallum, who headed the immunology section, said,

“She’s Harvard educated, and one of the most brilliant immunologists I’ve ever met. Speaking of off islanders, what really brings you to Bonefish Key?”

“My interest in marine biology,” Gamay said. “I’ve read in the scientific journals about the groundbreaking work you’ve been doing in biomedicine. I was planning to visit friends in Tampa and couldn’t pass up the opportunity to take a firsthand look.”

“Are you familiar with the history of the marine center?” asked Mayhew.

“I understand that you’re a nonprofit funded by a foundation, but I don’t know much beyond that,” Gamay said.

Mayhew nodded. “When Dr. Kane started the lab, his initial funding came from the bequest of a University of Florida alumna who had lost a close relative to disease. There were some legal challenges to the will from disgruntled family members, and the funding was about to dry up when he formed a foundation and started attracting money from other sources. Dr. Kane envisioned Bonefish Key as the ideal research center because it would be away from the hubbub of a busy university.”

A bell rang to announce dinner, and they moved into the dining room, the bartender taking over as waiter. The meal prepared by the chef was fresh-caught redfish, with a pecan crust and seared to perfection, washed down with a delicate French sauvignon blanc. Conversation around the table was on the light side, with little talk about the work being done on the island.

After dinner, the scientists moved out onto the veranda and the patio. There was more chatter, almost none of it having to do with the lab. As darkness deepened, most drifted off to their cabins.

“We hit the sack early here,” Mayhew explained, “and we’re up with the sun. We close the bar, so there’s not much action after ten o’clock.”

Mayhew asked Gamay a few more polite questions about her work at NUMA, then excused himself and said he would see her at breakfast. Any remaining staff followed, leaving Gamay alone on the veranda to absorb the sights and sounds of the subtropical night.

Gamay decided to call Paul, and she followed the same path to the water tower that she had taken earlier. The crushed white shells glowed under the brilliant moon. She started up the tower, only to stop in midstep. A female voice was coming from the platform. Speaking in what sounded like Chinese.

The conversation ended after a minute or two, and Gamay heard soft footfalls descending. Gamay backed down the ladder and hid behind a palmetto. She watched Dr. Lee descend the ladder, then hurry off down the path.

Gamay followed the path to the cabins. All were dark except for one, and, as she watched, the light in its window went out. She stood there looking at the darkened cabin, wondering what Nancy Drew would do in a case like this.

She decided to go back to the water tower. There, she left a voice mail on Paul’s phone, saying she had arrived safely, then headed back to her room.

She sat on her screened-in porch and tallied up the impressions of the few short hours she had spent on the island. Her natural powers of intuition had been honed by years as a scientific observer, first as a nautical archaeologist, then as a marine biologist.

She had picked up on Dooley’s suggestion that there was more than meets the eye on Bonefish Key. The man who had mixed her drinks looked as if he had stepped out of the pages of Soldier of Fortune magazine. Then Mayhew and his people were laughingly clumsy in their attempts to be evasive whenever talk touched on Dr. Kane, the center’s mysterious field project, and the whereabouts of the rest of the staff. She was intrigued, too, by the young Asian scientist who had given her the cold shoulder at the dock, and how Mayhew had conveniently forgotten to mention Dr. Song Lee. And how the other scientists avoided Gamay as if she were a leper.