In this famed Hitchcok feature, Dr. Edwardes, a famous psychiatrist, comes to Green Manors mental asylum to replace the retiring Dr. Murchison. Although Edwardes is attracted to Constance Petersen, she discovers by comparing handwriting, that he is an amnesiac imposter by the name of John Ballantyne. John Ballantyne and Dr. Peterson travel together in the night, pursued by the police, trying to unlock the mystery of what happened to the real Dr. Edwardes.
The film is particularly memorable for a surrealist interlude directed by artist Salvador Dali. The sequence, which accompanies John Ballantyne's description of a reoccurring nightmare is full of iconic psychoanalytic symbols: eyes, curtains, scissors, playing cards (some of them blank), a man with no face, a man falling off a building, a man hiding behind a chimney dropping a wheel, and wings.