“My personal car?” said Tibor. “No. I own it, but we use it as a cab. We have a number of regular customers who don’t want a taxi with a sign on it. We take them to restaurants and parties. In Hungary, the legal amount of alcohol you can drink and drive is zero, so they need to be driven. Me, I walk. I don’t need a car.”

Sam loaded the metal detector, three short-handled spades, and night vision goggles into the trunk and climbed into the sedan with the others. Tibor drove them north along the river, staring intently into the rearview mirror at times.

“Are we being followed?” asked Remi.

“I don’t think so,” Tibor said. “It’s hard to tell on these country roads, though. If somebody is behind you when you leave one town, he’ll stay behind you all the way to the next town. And it’s dark, so all you can see is his headlights.”

“But you don’t think anyone is following us?”

“No. The one who’s been behind us all this time drives like my grandmother. Anybody we have to worry about would be bold and crazy.”

Sam and Remi caught each other looking out the back window and smiled. Sam said, “At the next town, let’s double back and see if he does too.”

“Good idea,” said Tibor. He pulled up next to a restaurant at the next town, then drove around it along a narrow and winding road that would accommodate just one car at a time, emerging again near the restaurant. Then he pulled back onto the highway. They didn’t see a car ahead of them, but they could no longer see the car behind them either, so they felt reassured.

Sam used the GPS on his phone and directed Tibor the rest of the way. When he saw they were nearing the edge of a huge vineyard outside the city of Kiskunhalas, he said, “Turn your headlights off.” The road ahead went dark, and the car rolled to a stop. In the moonlight it was possible to see, on their left, a low hillside gently curving upward like an amphitheater. There were long rows of vines on weathered stakes connected by strands of wire for support. Sam, Albrecht, and Remi got out of the car, took the metal detector, the night vision goggles, and the short-handled, sharp-bladed spades for digging in the sandy soil out of the trunk and closed it quietly. Sam bent close to Tibor’s window and said, “Wait for us somewhere out of sight, and keep your phone on. If you see someone coming, or the sun is about to rise, call.”

“There are woods up ahead. I’ll be waiting there.” Tibor drove slowly off, turned, and disappeared into the night.

The three climbed a low rail fence and walked to what they judged to be midway along the crescent-shaped accumulation of soil. Then Sam turned on the metal detector and began to search. He bent over, to present a low profile, and walked up and down the rows of vines, stopping at the end of each row and then moving to the next.