 In a rigged gunfight Tom Blake is forced to shoot a man in self defense and is then hunted for murder. After a long trip fleeing the posse he uses a false name and joins the Pony Express which is just about to commence operatons. Relegated to the most dangerous section of the route, he finds himself fighting the District Manager s scheme to sabotage the inital run. But just then a wanted poster with his picture on it arrives.