[CHAPTER XXIV—A SPY CAPTURED]
“I haven’t seen any further flashes, Jack. Have you?”
“No, Frank. Bob, what do you make of it?”
“Well, you know more about radio than we. As far as I know, that light wasn’t any indication that the radio was in use, because there is no such indication possible.”
“You’re right, of course, Bob. That light was a signal to somebody somewhere. I wonder——”
“What?” asked Frank.
“Whether it was a signal to some ship off shore?”
“Or to the smugglers who are inland,” suggested Frank.
“It might have been the latter,” said Jack. “I hadn’t thought of that. Let’s see whether this hilltop commands a view up the canyon.”
They had paused beside a clump of rocks some thirty feet from the nearest corner of the radio station, after toiling up the steep slope. They spoke in whispers. Not a sign of life was apparent about the