To those who have read any of the twelve previous volumes in this "Rover Boys Series" the three brothers will need no special introduction. For the benefit of new readers allow me to state that Dick was the oldest, fun-loving Tom next, and Sam the youngest. They were the sons of Anderson Rover, a widower and rich mine owner. The father was a great traveler, and for years the boys had made their home with their uncle, Randolph Rover, and their Aunt Martha, on a farm called Valley Brook, in the heart of New York state. From the farm, and while their father was in Africa, the boys had been sent to Putnam Hall, as related in the first volume of this series, entitled, "The Rover Boys at School." At the Hall they made a score of friends and several enemies, some of which will be introduced later. A term at school was followed by a trip on the ocean, and then one into the jungles of the Dark Continent in search of Mr. Rover, who had mysteriously disappeared. Then the Rover boys went out west and to the great lakes, and later spent a fine time hunting in the mountains. They likewise spent some time in camp with their fellow cadets, and during the summer vacation took a long trip on land and sea. Then they returned home, and during another vacation sailed down the Ohio River in a houseboat, spent some time on the plains, took an unexpected trip to southern waters, and then came back to the farm. On getting back home, as related in the twelfth volume of this series, called "The Rover Boys on the Farm," the boys had imagined that adventures for them were a thing of the past. They were willing to take it easy, but this was not to be. Some bad men, including a sharper named Sid Merrick, were responsible for the theft of some freight from the local railroad, and Merrick, by a slick trick, obtained possession of some traction company bonds belonging to Randolph Rover. The Rover boys managed to locate the freight thieves, but Sid Merrick got away from them, dropping a pocketbook containing the traction company bonds in his flight. This was at a time when Dick, Tom and Sam had returned to Putnam Hall for their final term at that institution. At the Hall they had made a bitter enemy of a big, stocky bully named Tad Sobber and of another lad named Nick Pell. Tad Sobber, to get even with the Rovers for a fancied injury, sent to the latter a box containing a live, poisonous snake. The snake got away and hid in Nick Pell's desk and Nick was bitten and for some time it was feared that he might die. He exposed Tad Sobber, and fearing arrest the bully ran away from the Hall. Later, much to their surprise, the Rover boys learned that the bully was a ward and nephew of Sid Merrick, and when the sharper disappeared Tad Sobber went with him. "They are certainly a bad pair," said Dick, but how bad the Rovers were still to find out.