Dick and Doc, two look-alike cousins nicknamed the “Tarzan Twins,” set out to spend their school holiday at Tarzan’s African estate, only to become stranded in the jungle after an unexpected accident and fall into the hands of a cannibal tribe. After escaping and reuniting with Tarzan, the boys are drawn into an even more dangerous adventure when Gretchen von Harben, a missionary’s daughter, is kidnapped by exiles from Opar who intend to make her their new high priestess and revive the practice of human sacrifice. Together with Tarzan and his golden lion Jad-bal-ja, the boys rescue Gretchen and defeat the fanatics’ scheme, bringing their jungle adventure to a close as a story of courage, friendship, and youthful resourcefulness.