The construction of the Great Western Railroad creates heavy conflict between the railway company and neighboring Indian tribes. Worse, criminal gang leader Santer sets his eyes on a gold mine located on holy Indian land and influences the construction supervisor to re-rout the planned railroad straight through Apache land. Old Shatterhand, who works as a measurement technician, discovers the evil plan and searches contact with the Apaches in an effort to avert war.
Fred Engel's father is murdered by Colonel Brinkley in order to acquire a treasure map, however the Colonel only acquires half of it, the other half as held by Mrs. Butler. Discovering the scene of the crime, Old Shatterhand and Winnetou help Fred bring his father's murderer to justice and locate the treasure of Silver Lake.
Strange things happen in a revue theatre. The dancer Maria seems to be hunted by an invisible admirer. When the body of a probable FBI agent is found in a trunk the police asks FBI man Joe Como for help. Como gets interested in the revue theatre and an ominous transport firm soon. When he is receiving mysterious threatening letters he is sure that Dr. Mabuse has risen again. But what is going on at "Enterprise X" so that both the goverment and the mad genius in crime are interested in it?
