"Late-afternoon infrared is your best bet," Stern said. He was sitting in a chair with an ice pack on his knee.

"Why late afternoon?"

"Because this limestone holds heat. That's why the cavemen liked it so much here. Even in winter, a cave in Périgord limestone was ten degrees warmer than the outside temperature."

"So in the afternoon.. ."

"The wall holds heat as the forest cools. And it'll show up on infrared."

"Even buried?"

Stern shrugged.

Chris sat at the computer console, started hitting keys. The computer made a soft beep. The image switched abruptly.

"Oops. We're in e-mail."

Chris clicked on the mailbox. There was just one message, and it took a long time to download. "What's this?"

"I bet it's that guy Wauneka," Stern said. "I told him to send a pretty big graphic. He probably didn't compress it."

Then the image popped up on the screen: a series of dots arranged in a geometric pattern. They all recognized it at once. It was unquestionably the Monastery of Sainte-Mère. Their own site.

In greater detail than their own survey.

Johnston peered at the image. He drummed his fingers on the tabletop. "It's odd," he said finally, "that Bellin and Kramer would both just happen to show up here on the same day."

The graduate students looked at each other. "What's odd about it?" Chris said.

"Bellin didn't ask to meet her. And he always wants to meet sources of funding."

Chris shrugged. "He seemed very busy."

"Yes. That's the way he seemed." He turned to Stern. "Anyway, print that out," he said. "We'll see what our architect has to say."

Katherine Erickson - ash-blond, blue-eyed, and darkly tanned - hung fifty feet in the air, her face just inches below the broken Gothic ceiling of the Castelgard chapel. She lay on her back in a harness and calmly jotted down notes about the construction above her.

Erickson was the newest graduate student on the site, having joined the project just a few months before. Originally, she had gone to Yale to study architecture, but found she disliked her chosen field, and transferred to the history department. There, Johnston had sought her out, convincing her to join him the way he had convinced all the others: "Why don't you put aside these old books and do some real history? Some hands-on history?"

So, hands-on it was - hanging way up here. Not that she minded: Kate had grown up in Colorado and was an avid climber. She spent every Sunday climbing the rock cliffs all around the Dordogne. There was rarely anyone else around, which was great: at home, you had to wait in line for the good pitches.

Using her pick, she chipped off a few flakes of mortar from different areas to take back for spectroscopic analysis. She dropped each into one of the rows of plastic containers, like film containers, that she wore over her shoulders and across her chest like a bandolier.

She was labeling the containers when she heard a voice say, "How do you get down from there? I want to show you something."

She glanced over her shoulder, saw Johnston on the floor below. "Easy," she said. Kate released her lines and slid smoothly to the ground, landing lightly. She brushed strands of blond hair back from her face. Kate Erickson was not a pretty girl - as her mother, a homecoming queen at UC, had so often told her - but she had a fresh, all-American quality that men found attractive.

"I think you'd climb anything," Johnston said.

She unclipped from the harness. "It's the only way to get this data."

"If you say so."

"Seriously," she said. "If you want an architectural history of this chapel, then I have to get up there and take mortar samples. Because that ceiling's been rebuilt many times - either because it was badly made and kept falling in, or because it was broken in warfare, from siege engines."

"Surely sieges," Johnston said.

"Well, I'm not so sure," Kate said. "The main castle structures - the great hall, the inner apartments - are solid, but several of the walls aren't well constructed. In some cases, it looks like walls were added to make secret passages. This castle's got several. There's even one that goes to the kitchen! Whoever made those changes must have been pretty paranoid. And maybe they did it too quickly." She wiped her hands on her shorts. "So. What've you got to show me?"

Johnston handed her a sheet of paper. It was a computer printout, a series of dots arranged in a regular, geometric pattern. "What's this?" she said.

"You tell me."

"It looks like Sainte-Mère."

"Is it?"

"I'd say so, yes. But the thing is…"

She walked out of the chapel, and looked down on the monastery excavation, about a mile away in the flats below. It was spread out almost as clearly as the drawing she held in her hand.

"Huh."

"What?"

"There's features on this drawing that we haven't uncovered yet," she said. "An apsidal chapel appended to the church, a second cloister in the northeast quadrant, and… this looks like a garden, inside the walls… Where'd you get this picture, anyway?"

The restaurant in Marqueyssac stood on the edge of a plateau, with a view over the entire Dordogne valley. Kramer looked up from her table and was surprised to see the Professor arriving with both Marek and Chris. She frowned. She had expected to have a private lunch. She was at a table for two.

They all sat down together, Marek bringing two chairs from the next table. The Professor leaned forward and looked at her intently.

"Ms. Kramer," the Professor said, "how did you know where the rectory is?"

"The rectory?" She shrugged. "Well, I don't know.

Wasn't it in the weekly progress report? No? Then maybe Dr. Marek mentioned it to me." She looked at the solemn faces staring at her. "Gentlemen, monasteries aren't exactly my specialty. I must have heard it somewhere."

"And the tower in the woods?"

"It must be in one of the surveys. Or the old photographs."

"We checked. It's not."

The Professor slid the drawing across the table to her. "And why does an ITC employee named Joseph Traub have a drawing of the monastery that is more complete than our own?"

"I don't know… Where did you get this?"

"From a policeman in Gallup, New Mexico, who is asking some of the same questions I am."

She said nothing. She just stared at him.

"Ms. Kramer," he said finally. "I think you're holding out on us. I think you have been doing your own analysis behind our backs, and not sharing what you've found. And I think the reason is that you and Bellin have been negotiating to exploit the site in the event that I'm not cooperative. And the French government would be only too happy to throw Americans off their heritage site."

"Professor, that is absolutely not true. I can assure you-"

"No, Ms. Kramer. You can't." He looked at his watch. "What time does your plane go back to