“This is mighty bad,” was Sam’s comment.  “Why, Tom, this is positively dangerous.  If anybody should come along here——­”

“Hark!” Tom put up his hand, and both boys listened.  From the top of the hill they had left but a moment before, came the sounds of an approaching automobile.  An instant later the rays of the headlights shot into view, almost blinding them.

“We must stop them!” came from both boys simultaneously.  But scarcely had the words left their lips, when they saw that such a course might be impossible.  The strange automobile was coming down the hill at a furious rate.  Now, as the driver saw the Rovers’ machine, he sounded his horn shrilly.

“He’ll have a smash-up as sure as fate!” yelled Sam, and put up his hand in warning.  Tom did likewise, and also yelled at the top of his lungs.

But it was too late.  The occupant of the strange automobile—­ for the machine carried but a single person—­ tried to come to a stop.  The brakes groaned and squeaked, and the car swept slightly to one side, thus avoiding the Rovers’ machine.  Then, with power thrown off and the hand-brake set, it rolled out on the bridge.  There was a snap, followed by a tremendous crash, and the next instant machine and driver disappeared with a splash into the swiftly-flowing river.

CHAPTER II

 To the rescue

The accident at the bridge had occurred so suddenly that, for the instant, neither Rover boy knew what to do.  They saw that the farther end of the bridge had given way completely.  Just where the end rested in the water they beheld several small objects floating about, one of them evidently a cap, and another a small wooden box.  But the automobile with its driver was nowhere to be seen.

“My gracious!  That fellow will surely be drowned!” gasped Sam, on recovering from the shock.  “Tom, do you see him anywhere?”

“No, I don’t.”  Tom took a few steps forward and gazed down into the swiftly-flowing stream.  “Perhaps he is pinned under the auto, Sam!”

“Wait, I’ll get the searchlight,” cried the younger Rover, and ran back to their automobile.  The boys made a point of carrying an electric pocket searchlight to be used in case they had to make repairs in the dark.  Securing this, and turning on the light, Sam ran forward to the river bank, with Tom beside him.

To those who have read the previous volumes in this “Rover Boys Series” the lads just mentioned will need no special introduction.  For the benefit of others, however, let me state that the Rover boys were three in number; Dick being the oldest, fun-loving Tom coming next, and sturdy Sam being the youngest.  When at home, which was only for a short time each year, the boys lived with their father, Anderson Rover, and their Uncle Randolph and Aunt Martha on a farm called Valley Brook, in New York State.

While their father was in Africa, the boys had been sent to Putnam Hall Military Academy, as related in the first volume of this series, entitled “The Rover Boys at School.”  There they had made quite a few friends, and, also, some enemies.*