Isabelle and Bruno kept in touch, but there had been long interruptions between reunions, which made them all the sweeter. There was no other person in sight, but the boats out in the bay were jolting along the vast rows of oyster beds, stopping every few moments to take aboard more of the cages that carried the oysters that would grace half the tables of France on New Year’s Eve.

“I’m starting to freeze, but it must be even colder for the fishermen out there,” said Isabelle.

“You’ll warm up again on the way down this dune,” said Bruno. He felt comfortable in the heavy wool of his old army overcoat and happy just to be holding her close. “Most people end up tripping and rolling all the way to the bottom. The sand is soft, though. Your only problem is that the sand gets everywhere.”

“Is it true that the dune moves?” she asked.

“They say it creeps back a little toward the land every year,” he replied. “There are old maps that show it used to be farther south and a few hundred meters out to sea. The tides here are strong. They rise four or five meters every day, and the wind drives the whole Atlantic Ocean against this shore.”

“And you’ll be out there tonight.” He noticed that she made an effort to keep the concern out of her voice.

So he would, one of thirty policemen brought in from rural areas so they would not be recognized by the locals, all called in for a police operation against the recurrent thefts of oysters. Clearing out a whole bed could net the thieves fifty thousand euros or more. The oysters took three years to grow from spawn, and after the devastation caused to the beds by the red tide plankton, supercharged by the runoffs of fertilizers, few oyster growers could survive a major theft.

That morning, while Bruno was waiting for Isabelle to arrive from Paris, he had sat with the rest of the team in the large briefing room at Bordeaux police headquarters as Commissaire Pleven, the man in charge of what he called Operation Dominique, laid out his plan. Pleven had not explained the name, whether it was a random identifier spewed up by some computer or in honor of his wife, but the resources he had assembled were impressive.