Rose Kotter works in the emergency psychiatric department, and one day she encounters a seemingly typical patient—a student who, a few days earlier, had witnessed a professor's suicide. The girl, in a hysterical state, claims that she is sane and is being haunted by a malevolent entity. Then, with a terrifying smile, she slits her own throat. From that moment, Rose begins to see a smiling suicide victim in the most inappropriate places, and her life gradually falls apart.