Johnny Wiessmuller swings into action as Tarzan! Caught between two worlds, a man who was orphaned in the African jungle as a baby and raised by apes has grown to rule and to protect the wild beasts, a hero known only as Tarzan. When Tarzan travels to the African coast, a beautiful, young woman becomes trapped in his fishing net. He learns the woman--who's so at home under water that she seems to be a mermaid--has fled the pearl-fishing village of Aquatania and a forced betrothal to its evil living god, Balu. When Balu's henchman recapture the girl, Tarzan travels to the town of the pearl divers, don's the god's enchanted mask and exposes Balu as a fraud in the adventure of Tarzan and the Mermaids.