“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.

Albrecht and Remi knelt at either end of the rows, watching through their night vision goggles for any sign of people coming. Occasionally they would switch to the infrared setting to see if they could pick up heat from a human being in any direction, then switch back to normal night vision. None of the three shone any light, and there was no sound except for the steady, faint summer breeze through the grapevine leaves and the slough of Sam’s shoes on the soft ground between the staked vines.

Sam moved methodically from the upper end of the crescent down toward the flat land. The crescent framed a loop made in the river where the channel curved and the water slowed. The alluvial soil had been deposited there before the river was diverted—highest at the midpoint of the curve and tapering on both ends.