“Dr. Bird?” asked the newcomer. “I am Tom Harron, United States Marshal. These two men are deputies. I understand that I am to report to you for orders.”
“I’m glad to know you, Mr. Harron. This is Operative Carnes of the Secret Service and Commander Minden of the Coast Guard. We are going to explore an underground cavern that is located in this vicinity.”
“Do you mean the one where they used to smuggle aliens? That is closed up. I was in charge of that work and we closed it tight as a drum two years ago.”
“Can you find the entrance?”
“Sure. It isn’t over a mile from here.”
“Lead the way, then. We want to take a look at it.”
The marshal led the way toward the eminence and took a path which led up a gully in its side. He paused for a moment to take his bearings and then turned sharply to his left and climbed part way up the side of the ravine.
“Here it is,” he announced. An expression of astonishment crossed his face and he examined the ground closely. “By Golly, Doc,” he went on as he straightened up, “this place has been opened since I left it!”
Dr. Bird hurried forward and joined him. The heavy stone and concrete with which the entrance to 349 the cavern had been sealed were undisturbed, but in the side of the hill was set a steel door beside the concrete. There was no sign of a keyhole or other means of entering it.