
In 19th century London, Dr. Charles Marlowe experiments with a mind-altering drug which causes him to develop an evil alter ego, Edward Blake, whom his colleague begins to suspect is someone that is blackmailing Marlowe.
Christopher LeeDr. Charles Marlowe / Mr. Edward Blake
Peter CushingFrederick UttersonMike RavenEnfield
Richard HurndallLanyon
George MerrittPoole
Kenneth J. WarrenDeane
Susan JamesonDianeMarjie LawrenceAnnie
Aimée DelamainLandlady
Michael Des BarresBoy in alley
Ian McCullochMan at Bar (uncredited)
Chloe FranksGirl in Alley (uncredited)