The three made their way to the foot of the low mountains that dotted the horizon. As GS had said, there were a lot of caves.
"We don't have time to search every one of these," Lee said, frustration evident in his voice.
"I don't think we need to," GS said. "If I'm not mistaken, the machine Nancy has will have to put off some kind of signal. Major, do you have any kind of testing device in that car of yours? Something that will pick up betavoltaic emissions?"
Lee sent a startled look her way. "Why, yes, I have the prototype for an analyzer that can detect increased betavoltaic use, but how..."
He stopped as she held her palm up to him and turned to Mark.
"While the Major is busy doing that, you and I are going to walk that way. I want you to keep your eyes peeled for anything that looks... wrong. I'm going to be focusing on what I can hear. My instincts tell me Nancy's machine will not be completely silent and I think I might can pick up on the sound waves."
Without another word, GS started moving purposefully toward the caves. Mark looked at Lee, shrugged his shoulders, and followed her.