"That's so, too! Well, come ahead, let's hurry and see if we can catch sight of them." And then the two boys pushed ahead faster than ever.
Presently the youths came to where there were a number of high rocks covered with trailing vines. As, to avoid these, it would have been necessary to wade in the stream, and thus get their shoes and stockings wet, they began to scramble over the rocks with all possible speed.
"Listen! They are talking again!" exclaimed Sam.
"Grab him! Grab him by the throat!"
"That's all right, Jim, but I don't want the boat to upset," growled another voice.
"Say, you fellows make me tired!" roared the heavy bass voice. "Do you want to keep us here all day?"
"What do you know about this gun? Maybe it will explode."
"Say, Sam, I don't know what to make of this!" panted Tom, who was almost out of breath from the violence of his exertion.
"Maybe they are tramps, and are holding somebody up. Anyway, it sounds bad," returned his brother.
Hauling themselves at last to the top of the rocks, the Rover boys looked ahead. Down in the swiftly-flowing stream, they saw a flat-bottom boat containing two men. One man, a tall, burly individual, had a much smaller fellow by the throat, and was bending him backward. Close at hand, on the shore, stood another man, gun in hand, and with the weapon aimed at the burly individual.