Lamar Public Library

When the Hardy Boys set out to solve the mystery of their missing chums, they discover a gang hide-out in a cave on an island along the way.

Joe and Frank suspect there is a link between the counterfeiting case they are investigating, and the case their father can't discuss. Determined to learn the secret, the Hardy Boys get themselves into a scrape.

Joe, Frank, and their friends search the icebound Cabin Island for a missing boy and some stolen medals.

Learning that the Ebony Pearl, which was shipwrecked some forty years earlier, has risen from the bottom of the sea near Nantucket, the Hardys race to the scene to discover its mystery and to prevent a murder.