The film's action takes place in a psychiatric clinic, Green Manors, where the institute's new director, Dr Anthony Edwardes, arrives. Doctor Constance Petersen, the leading woman played by Ingrid Bergman, works in the clinic.
The arrival of the new director Edwardes, played by Gregory Peck, is immediately suffused with an aura of suspense. The man, in fact, will be discovered, is not the real director, but John Ballantyne, a mysterious individual who suffers from dissociative amnesia.

Ballantyne is also convinced that he is the killer of the real Dr Edwardes. Dr Petersen falls in love with him and tries to solve the puzzle about Ballantyne's identity. By managing the balance between her professionalism and the emotional tension arising from the feeling she feels for the man, she will try to cure him of his phobias and discover the real murderer of Dr Edwardes.