Black Friday (1940)
Karloff plays a only slightly mad doctor who did a brain switch between a dying mobster and his fatally injured Academic friend. The Gangster (now in the other body) comes back incognito to get revenge on his old gang, lead by Bela Lugosi.
Though the 2 horror icons headline the poster, surprisingly it is the acting of Stanley Ridges that steals the show. He is hypnotic as he switches between the mild mannered professor and the tough guy mobster. The film is an entertaining watch but disappointing as Karloff and Lugosi never share a scene.