So far Dave had kept silent, drinking in all that was said.
He realized only too well what a plot was going on against his father and himself, and against the Swallow.
"If only I can get free, I'll show them a trick or two," he told himself.
Suddenly Bart Hankers uttered a cry.
"A snake! A snake!"
He was right; a long snake had appeared at the top of the underground stream.
It was a dangerous-looking reptile, eight feet long, and with nasty green eyes.
Bart Hankers fell back in confusion.
But instead of climbing to the outer bank, the snake crawled out close to the rock behind which Dave was in hiding.
It was against human nature to remain hidden under the circumstances, and the young diver leaped up with all rapidity.