Hired to locate an old Spanish cannon, the Hardy brothers uncover an even greater treasure after perilous underwater adventures.

In a series of hair-raising adventures both on land and undersea the teenage brother detectives pit their wits against some of the most ruthless criminals they

In solving the mystery of two medallions missing from an inherited curio collection, the Hardys wind up in a desolate area of Guatemala at the mercy of dangerou

As a final step in solving a mystery, Frank and Joe face the ghost at Skeleton Rock.