The film tells the story of Scottie Ferguson (Stewart), a retired police detective who suffers from acrophobia (fear of heights). He is hired by Gavin Elster (Tom Helmore) to follow his wife, Madeleine (Novak). Scottie becomes obsessed with Madeleine and her mysterious behavior. He follows her to a mission, where he sees her jump to her death.
Scottie is devastated by Madeleine's death and begins to hallucinate. He sees Madeleine everywhere he goes. He is eventually able to overcome his acrophobia and confront the truth about Madeleine's death.