 Hearing of a native uprising at the African Copper Mines at Karanga, manager Edmund Daniels (Addison Richards) and American counsel Jeff Worthing (Charles Bickford) catch an arms-and-ammunition bearing train. Other passengers include Paul Stacco (Maurice Moscovitch), a sort of native white god expected to settle the rebellion peacefully; Daniels s secretary David Wallace (John Sutton); Dr. Greenleaf (Frank Reicher) and his nurse Julia Garrett (Luli Deste); Steve Harley (James Craig), a young American adventurer; Manek Sen (Abner Biberman), a mysterious Eurasian; and Slats Breese (Paul Hurst), an American fight trainer. Daniels is murdered on the train and an investigation reveals that Dr. Greenleaf s real name is one notorious in medical circles, and that Manek Sen is set on killing Hawley to get the latter s treasure maps. Daniel s papers are found in Stacco s possession. Julia is wounded when the natives, under Stacco s orders, attack the train. Later, Jeff exposes Wallace as Daniels  killer, as Daniels had discovered he had been stealing from the mine.