Nightmare

Clarinetist Stan Grayson (Kevin McCarthy) has a nightmare about killing a man in a mirrored room. Upon waking and finding blood marks on himself and a key from the dream, he suspects that it may have truly happened. He turns to his police detective brother-in-law, Rene Bressard (Edward G. Robinson), for help as Stan leads his girlfriend and sister to an empty house where the nightmare took place.