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.