Black Friday

After a university professor is severely injured during a confrontation with gangsters, a surgeon attempts an experimental procedure to save him. By transplanting a portion of the brain from a critically wounded criminal into the professor's skull, the doctor manages to preserve his life. However, the operation results in a dual personality, as the professor begins to exhibit the traits and memories of the gangster.

This 1940 American production from Universal Pictures was directed by Arthur Lubin. In the chronological sequence of his work, it follows Prison Break and precedes Hold That Ghost. The film features a cast including Stanley Ridges, who plays both the professor and the criminal, alongside Boris Karloff and Bela Lugosi. The screenplay was written by Curt Siodmak and Eric Taylor, with a total of 35 credited cast members.

The movie blends elements of crime, drama, horror, mystery, and science fiction over a 70-minute runtime. It has received a generally positive response from viewers, maintaining a 6.3 rating on IMDb based on 3,300 votes and a 6 rating on TMDB from 61 votes.