Dastardly criminal genius Dr. Mabuse (Wolfgang Preiss) appears in three fiendish adventures in this classic horror triple feature. The Return of Dr. Mabuse finds the evil mastermind in cahoots with the Chicago mob; in The Invisible Dr. Mabuse, FBI man Joe Como investigates the murder of a fellow agent; and in The Death Ray Mirror of Dr. Mabuse, the mad criminal threatens the world with his death ray. It's a triple threat in this pulp horror fest.