In the sixth adventure in Robert Arthur's classic mystery series, the Three Investigators travel to southern Florida, where the ghost of a young girl on a haunted carousel threatens a film crew shooting on an island off the coast. There they meet a Greek boy, Christos Markos, who's an expert deep-sea diver. In the face of sudden danger, ugly rumors, and continuing mysterious events, can Jupiter, Pete, and Bob save Chris's reputation, unravel the mystery of the young girl's ghost, and rescue the movie from disaster?