The Rover boys were three in number, Dick being the oldest, Tom coming next, and Sam the youngest. In their younger days they had resided with their parents in New York, but after the death of their mother and the disappearance of their father they had gone to live with their uncle, Randolph Rover, and their Aunt Martha, on a farm called Valley Brook, near the village of Dexter Corners, on the Swift River. Those who have read the previous volumes of this series, entitled respectively, "The Rover Boys at School." "The Rover Boys on the Ocean," and "The Rover Boys in the jungle," know that our three heroes had already passed through many trying experiences and thrilling adventures. From home they had been sent to Putnam Hall, a military academy of high standing, and here they had made many friends, including those already mentioned, and several enemies, among the latter being one Dan Baxter, who was known as the school bully, and John Fenwick, better known as Mumps, the bully's toady. They had also made a bitter enemy of Josiah Crabtree, the headmaster of the Hall. But since those first days at the school many things had happened and many changes had occurred. It was discovered that Dan Baxter was the son of one Arnold Baxter, a rascal who had, years before, tried to swindle the Rover boys' father out of some valuable mining property in the West, and that the son was little better than his parent. Dan had left the school in a hurry, and soon after this his father had been arrested in Albany for a daring office robbery, and was now in jail in consequence. The disappearance of Dan, and Josiah Crabtree's yearning for wealth, had led to further complications. Near Putnam Hall resides the widow Stanhope and her pretty daughter Dora, and Crabtree, who exerted a sort of hypnotic power over the widow, tried to get the lady to marry him, so that he might obtain the fortune she held in trust for her daughter. But how the Rover boys fooled the grasping teacher, and how Dora was saved from the plot Crabtree and Dan Baxter hatched up against her, has already been told in "The Rover Boys on the Ocean."