the helicopter, a large gray metal box equipped with a small monitor and a keypad was bolted to one side. A tubular projection hung a couple of feet from the box outside of the open sliding door.

"That's the ground-penetrating radar. We'll be able to find the distinct depression in the ground that Peter believes might be the location we need, but we need you guys in the boat to be following us and get there on the ground," said Frankie.

"Why can't we just do that once you find it?" Wilder said.

"Using a GPR from the air won't give us very good reception. We need to use this portable antenna in the boat to enhance the return signal," Frankie answered, handing Wilder a clunky gray cylinder with a black plastic tip and some blinking red LEDs. "Alrig...

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