A mysterious ancient idol called The Green Goddess is being worshipped by the jungle-natives of a lost city deep in Guatemala. Not only is it covered in rubies and jewels, it contains within it an age-old recipe for a gunpowder-like explosive. Major Martling (Frank Baker) and Ula Vale (Ula Holt) come from Africa to search out The Green Goddess. A mercenary named P.B. Raglan (Ashton Dearholt, also a producer of the film) is sent by Ula's lawyer to find the statue first. The Major and Ula meet up with Tarzan, who is on a mission to find his old pal, d'Arnot, whose plane crashed near the lost city. The group now must save d'Arnot and grab The Green Goddess before Raglan shares all secrets.