Bøger i Hardy Boys serien

A dying criminal confesses that his loot has been stored "in the tower." Both towers of the looted mansion are searched in vain. It remains for the Hardy boys to make an astonishing discovery that clears up the mystery and clears the name of a friend's father.

Brothers Frank and Joe try to find Steven Royal, a famous computer game designer who has disappeared with the prototype of his newest game.

When Frank and Joe join a volunteer project in the south of France, they hear that the ruined castle nearby may be haunted by the ghost of its lord, who was slain by bandits, and they wonder if the spooky events they witness are an attempt to sabotage their project.