The Rover boys have, of course, gradually been growing older. Dick and Tom are both married and doing what they can to carry on their father's business in New York City. Sam, the youngest of the boys, is still at Brill College. The particulars are given of some winter sports around that institution of learning, and then of a great baseball game in which the youngest Rover distinguishes himself. Then Sam graduates from college, and all the boys, with some others, go on a long automobile tour, during which a number of exciting adventures occur. The party is caught in a storm on the mountains, and later on are caught in a great flood. What the Rover boys did under such trying circumstances I leave for the pages which follow to disclose.