Vertigo

Scottie Ferguson resigns from the police force when he discovers he suffers from vertigo. He is asked by an old college friend, Gavin Elster to follow and keep an eye on his wife Madeleine. He does so and falls in love with her. The night they confess their love, Madeleine seems to throw herself to her death. Scottie has a nervous breakdown, but months later he meets a girl, Judy, who resembles Madeleine so much that he begins to fall in love with her. Meanwhile, it is shown in a flashback that Judy had posed as Madeleine as part of a plot to kill another woman.