Black Friday (1940 film)

Black Friday is a 1940 American science fiction crime horror film directed by Arthur Lubin. It stars Boris Karloff, Bela Lugosi, Stanley Ridges, Anne Gwynne, and Anne Nagel.

The film centers on Dr. Ernest Sovac (Karloff), a brilliant but ethically dubious neurosurgeon who saves the life of college professor George Kingsley (Ridges) after a near-fatal car accident. To save Kingsley, Sovac transplants a portion of the brain of notorious gangster Red Cannon into the professor.

As Kingsley recovers, the criminal personality of Red Cannon begins to surface, vying for control of Kingsley's consciousness. Cannon’s memories and violent tendencies emerge, compelling Kingsley to seek out Cannon's hidden loot and settle old scores. Dr. Sovac, meanwhile, attempts to control Cannon's influence for his own purposes, leading to a series of murders and increasingly bizarre consequences. Lugosi plays a minor role as a gangster connected to Cannon. The film explores themes of identity, morality, and the dangers of tampering with the human brain.