She said, "But this isn't our project…"

"No," Marek said. "I'm just showing you the general layout in this region. All along the Dordogne, you find these paired, opposing castles. Our project also involves a pair of opposing castles, but it's a few miles downstream from here. We'll go there now."

The helicopter banked, heading west over rolling hills. They left the tourist area behind; Kramer was pleased to see the land beneath her was mostly forest. They passed a small town called Envaux near the river, and then climbed up into the hills again. As they came over one rise, she suddenly saw an open expanse of cleared green field. In the center of the field were the remains of ruined stone houses, walls set at odd angles to one another. This had clearly once been a town, its houses located beneath the walls of a castle. But the walls were just a line of rubble, and nearly nothing of the castle remained; she saw only the bases of two round towers and bits of broken wall connecting them. Here and there, white tents had been pitched among the ruins. She saw several dozen people working there.

"All this was owned by a goat farmer, until three years ago," Marek said. "The French had mostly forgotten about these ruins, which were overgrown by forest. We've been clearing it away, and doing some rebuilding. What you see was once the famous English stronghold of Castelgard."

"This is Castelgard?" Kramer sighed. So little remained. A few standing walls to indicate the town. And of the castle itself, almost nothing.

"I thought there would be more," she said.

"Eventually, there will be. Castelgard was a large town in its day, with a very imposing castle," Marek said. "But it'll be several years before it's restored."

Kramer was wondering how she would explain this to Doniger. The Dordogne project was not as far advanced as Doniger had imagined it to be. It would be extremely difficult to begin major reconstruction while the site was still so fragmented. And she was certain Professor Johnston would resist any suggestion to begin.

Marek was saying, "We've set up our headquarters in that farm over there." He pointed to a farmhouse with several stone buildings, not far from the ruins. A green tent stood beside one building. "Want to circle Castelgard for another look?"

"No," Kramer said, trying to keep the disappointment out of her voice. "Let's move on."

"Okay, then, we'll go to the mill."

The helicopter turned, heading north toward the river. The land sloped downward, then flattened along the banks of the Dordogne. They crossed the river, broad and dark brown, and came to a heavily wooded island near the far shore. Between the island and the northern shore was a narrower, rushing stream perhaps fifteen feet wide. And here she saw ruins of another structure - so ruined, in fact, that it was hard to tell what it once had been. "And this?" she said, looking down. "What's this?"

"That's the water mill. There was once a bridge over the river, with water wheels beneath. They used water power to grind grain, and to pump big bellows for making steel."

"Nothing's been rebuilt here at all," Kramer said. She sighed.

"No," Marek said. "But we've been studying it. Chris Hughes, one of our graduate students, has investigated it quite extensively. That's Chris down there now, with the Professor."

Kramer saw a compact, dark-haired young man, standing beside the tall, imposing figure she recognized as Professor Johnston. Neither man looked up at the helicopter passing overhead; they were focused on their work.

Now the helicopter left the river behind, and moved on to the flat land to the east. They passed over a complex of low rectangular walls, visible as dark lines in the slanting morning light. Kramer guessed that the walls were no more than a few inches high. But it clearly outlined what looked like a small town.

"And this? Another town?"

"Just about. That's the Monastery of Sainte-Mère," Marek said. "One of the wealthiest and most powerful monasteries in France. It was burned to the ground in the fourteenth century."

"Lot of digging down there," Kramer said.

"Yes, it's our most important site."

As they flew by, she could see the big square pits they had dug down to the catacombs beneath the monastery. Kramer knew the team devoted a great deal of attention here because they hoped to find more buried caches of monastic documents; they had already discovered quite a few.

The helicopter swung away, and approached the limestone cliffs on the French side, and a small town. The helicopter rose up to the top of the cliffs.

"We come to the fourth and final site," Marek said. "The fortress above the town of Bezenac. In the Middle Ages it was called La Roque. Although it's on the French side of the river, it was actually built by the English, who were intent on maintaining a permanent foothold in French territory. As you see, it's quite extensive."

And it was: a huge military complex on top of the hill, with two sets of concentric walls, one inside the other, spread out over fifty acres. She gave a little sigh of relief. The fortress of La Roque was in better condition than the other sites of the project, and it had more standing walls. It was easier to see what it once had been.

But it was also crawling with tourists.

"You let the tourists in?" she asked in dismay.

"Not really our decision," Marek said. "As you know, this is a new site, and the French government wanted it opened to the public. But of course we'll close it again when we begin reconstruction."

"And when will that be?"

"Oh… between two and five years from now."

She said nothing. The helicopter circled and rose higher.

"So," Marek said, "we've come to the end. From up here you can see the entire project: the fortress of La Roque, the monastery in the flats, the mill, and across the river, the fortress of Castelgard. Want to see it again?"

"No," Diane Kramer said. "We can go back. I've seen enough."

Edward Johnston, Regius Professor of History at Yale, squinted as the helicopter thumped by overhead. It was heading south, toward Domme, where there was a landing field. Johnston glanced at his watch and said, "Let's continue, Chris."

"Okay," Chris Hughes said. He turned back to the computer mounted on the tripod in front of them, attached the GPS, and flicked the power button. "It'll take me a minute to set up."

Christopher Stewart Hughes was one of Johnston's graduate students. The Professor - he was invariably known by that name - had five graduate students working on the site, as well as two dozen undergraduates who had become enamored of him during his introductory Western Civilization class.

It was easy, Chris thought, to become enamored of Edward Johnston. Although well past sixty, Johnston was broad-shouldered and fit; he moved quickly, giving the impression of vigor and energy. Tanned, with dark eyes and sardonic manner, he often seemed more like Mephistopheles than a history professor.

Yet he dressed the part of a typical college professor: even here in the field, he wore a button-down shirt and tie every day. His only concession to field work were his jeans and hiking boots.

What made Johnston so beloved by his students was the way he involved himself in their lives: he fed them at his house once a week; he looked after them; if any of them had a problem with studies, or finances, or family back home, he was always ready to help solve the difficulty, without ever seeming to do anything at all.

Chris carefully unpacked the metal case at his feet, removing first a transparent liquid crystal screen, which he mounted vertically, fitting it into brackets above the computer. Then he restarted the computer, so that it would recognize the screen.

"It'll just be a few seconds now," he said. "The GPS is calibrating."