The Secret of the Silver Dolphin

A newscast announcing a reward to anyone who can locate a valuable silver dolphin involves Louise and Jean Dana in a baffling search. Judy Platt is desperately trying to find the silver dolphin mentioned in her dead brother's will. But no one knows what kind of dolphin to look for—a live mammal or a silver object.

The Danas' sleuthing is hindered by a hostile fortune-teller and an elusive thief. The two are engaged in a sinister conspiracy to get the reward—and will stop at nothing to ensure the success of their criminal scheme.

Louise and Jean's quest for the silver dolphin leads them to Miami, Florida, and then to a deserted Caribbean island. A dangerous skin-diving chase, followed by an amazing undersea discovery, results in the Danas solving this intriguing mystery.