Mike Gregory, an airline pilot, crash lands in the desert of South-West Africa near the remains of an old wagon. Maria and Karl Du Val, the managers of a copper mine, nurse him back to health, and they express interest in the wagon. Maria attempts unsuccessfully to seduce Mike, but he returns to Johannesburg and learns that a wagon loaded with gold bullion was lost in the desert during the Boer War. Major Dillon suggests that he and Mike form an expedition; and with Dillon's son Jack, and Jack's girl friend, Helena, they set out for the desert to find the gold. During the trip they are attacked by an unknown assailant; their plane is burned, Major Dillon is wounded, and Jack and a desert policeman are killed. Maria and Karl Du Val, who are responsible for the sabotage, take Mike and Helena prisoner. Although Maria's advances are once again rejected by Mike, she repents of her role in the kidnaping and helps the hostages to escape. Du Val, now totally deranged, shoots Maria. Mike and Helena trace the gold bullion to a cave. Standing at the entrance is the skeleton of the original escort, still holding a machine gun. Du Val appears; Mike reveals that the bullion is actually lead, and Du Val lunges toward them. The machine gun discharges, and Du Val is killed.