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.
The Ghost of Frankenstein is a 1942 American horror film directed by Erle C. Kenton and starring Cedric Hardwicke, Lon Chaney Jr. and Bela Lugosi. It is the fourth film in the Frankenstein series by Universal Pictures, and the follow-up to Son of Frankenstein (1939). The film's plot follows the previous film's plot: Frankenstein's Monster and his companion Ygor are chased out of town. They go to another small town to encourage the younger son of Henry Frankenstein to continue his father's experiments, so that Ygor can have revenge against his enemies and his brain transplanted into the Monster's skull.