These had again suffered the ignominy of having their hands tied, after they had undressed, and, wrapped in the rubber ponchos given them by Bob, they had flung themselves down on the pallet prepared the previous night by the boys.
Stationed in the outer entrance of the cave, Tom Bodine looked around at the two prone forms several times. But always they lay motionless under their ponchos, and there seemed no cause for suspicion regarding them. Poor fellows, thought Tom, who held no particular animosity against them, they had had a hard time of it lately. After landing from a flying trip, they had been set upon and beaten. Then, made prisoner, they had spent the intervening hours cramped in bonds and in doubt as to what their captors intended doing with them. Probably were tired out and asleep by now, thought Tom. He even tiptoed over to where they lay and found, as he had expected, that both had their eyes closed and were breathing heavily.
Returning to the entrance, Tom took a step or two forward so as the better to see past the big rock outside and thus get a clearer view of the airplane. The boys had reached it by now, the oil flares were planted to both sides, and it was illuminated, standing out in the tossing light like a great bird.
As the propeller began to whirl, Tom took another step or two forward. An airplane was a new puzzle to him, and he was so interested in watching it get under way that he forgot his trust, forgot he had prisoners to watch, forgot everything but the mystery of that piece of mechanism, that gigantic bird, running bumpily now over the ground and now beginning to lift into the air, and now——
Tom whirled about. The old instinct of the man who lives much in the open, telling him danger is close at hand, was stirring at the roots of his hair. But he was just a trifle too late. As he faced about, a form shot out of the cave and Tom, totally unprepared for attack, was bowled over.
As he fell he let out a great wordless cry, thinking to warn Frank and Roy Stone. Then the butt of a revolver descended on his head.
CHAPTER XXIII
THE TABLES TURNED
"What was that?" asked Frank, turning to Roy Stone, as the airplane bearing Jack and Bob on their romantic adventure dwindled in the darkening sky. "I thought I heard a shout."
"Guess you did," said Stone. "I heard it, too. It came from the cave."