In an effort to find the site of an ancient Baku civilization, writer Ellen Marsten (Jean Byron), archer Bob Prentice (Bill Henry), and a trader named Santo turn to Olympic swimming champion and jungle guide Johnny Weissmuller (himself) for help. The safari is taken captive by the Moon Men, a pygmy tribe that worships the immortal high priestess Oma (Helene Stanton). Johnny struggles to free the captives in one of the final installments of the adventure series full of strange rituals and even stranger natives and wildlife that began with Weissmuller playing the character "Jungle Jim." Newly remastered