A fat white man called Paul de Kraft is hunting for emeralds in the Belgian Congo with a group of hired natives, but a strange bearded man living in the wild tries to send them off. De Kraft gets rid of the nuisance and kills the man. When he is about to shoot the dying man's son too, a lion attacks the villains and scares them away.

After finding a partner called Ed Kivlin to finance a new expedition, Paul de Kraft returns to the Belgian Congo to gather the emeralds and intends to get rid of his new ally after he's done. Once more, the native porters fear the White Jungle God and express their will to leave but de Kraft forces them to stay by killing anyone who flees. But Kivlin eventually confirms the existence of the white man and de Kraft finally realizes that he is the boy whose father he killed years ago. The weapons in his tent all disappear so de Kraft accuses his partner and kills him. When Ka-Zar finally shows up, de Kraft captures him and delivers him to the natives who claim the prisoner. Ka-Zar escapes from his bonds and stabs de Kraft, thus avenging his father.