Frankenstein's unscrupulous colleague, Dr. Bohmer, plans to transplant Ygor's brain so he can rule the world using the monster's body, but the plan goes sour when he turns malevolent and goes on a rampage.

Cast: Cedric Hardwicke, Ralph Bellamy, Lionel Atwill, Bela Lugosi, Evelyn Ankers, Lon Chaney Jr.