Scientist-explorer David Lynd (Terry) leaves wealthy bride-to-be June Claymore (Louise Allbritton) at the altar to join photographer Andy Parker (Devine) and British secret service agent Leo Marzeli (Carrillo) in search of rare minerals. They soon run afoul of crooked trader Tagani (Turhan Bey), who's been busily stockpiling weapons in the hills on behalf of his Nazi partners.