Black Friday

University professor George Kingsley is struck by gangsters while crossing the street, leaving him with brain damage and one of the gangsters, Cannon, paralyzed. Kingsley's friend Dr. Sovac attends to both men, and when Cannon offers him a reward for aiding his recovery, Kovac transplants part of Cannon's brain into the dying Kingsley's skull, creating a dual personality.

• 
  Arthur Lubin

• 
  Stanley Ridges
  Prof. George Kingsley / Red Cannon
• 
  Boris Karloff
  Dr. Ernest Sovac
• 
  Bela Lugosi
  Eric Marnay
• 
  Anne Nagel
  Sunny Rogers
• 
  Anne Gwynne
  Jean Sovac
• 
  Virginia Brissac
  Mrs. Margaret Kingsley
• 
  Edmund MacDonald
  Frank Miller
• 
  Paul Fix
  William Kane
• 
  Murray Alper
  Bellhop
• 
  Jack Mulhall
  Bartender
• 
  Raymond Bailey
  Louis Devore
• 
  Joe King
  Chief of Police
• 
  John Kelly
  Taxi Driver
• 
  Jessie Arnold
  Nurse
• 
  Elfriede Borodin
  2nd Nurse
• 
  Tommy Conlon
  Student
• 
  Franco Corsaro
  Club Maitre d' (uncredited)
• 
  James Craig
  Reporter Ernst Gives Notes To
• 
  Kernan Cripps
  Detective
• 
  Eddie Dunn
  Det. Farnow