This vintage 12-part serial follows adventurer Robert Grant (Walter Miller), who escapes from an Indian prison, travels to Africa, teams with winsome Muriel Armitage (Nora Lane) to locate her missing brother and battles a nasty sheik (Boris Karloff) for possession of a diamond mine. As Robert and Muriel try to clear him of murder charges and lay claim to the mine, they find themselves up against unfriendly natives and ferocious beasts.