The film begins with "Scottie" Ferguson, a [[police|police detective]] chasing a criminal across a city rooftop. During this chase, a fellow officer falls to his death, and Ferguson finds that his feat of heights has increased to a problem with vertigo. He has to retire from his police work as a result of his disability.
A former college friend of his, Gavin Elster, hires Scottie to spy on his wife Madeleine, telling him that she has been acting strangely and he suspects she may be suicidal. Scottie trails Judy to an [[museum|art museum]], where he watches her as for three hours as she stares intently at a portrait of Carlotta Valdes, a Spanish matron who has been dead for more than two centuries. Then she goes and buys flowers and puts them on Carlotta's grave.
Scottie determines that Madeleine is depressed; that she is obsessed with a dead Spanish woman; and that she has only one suit, which is gray. After a few days of observation, Madeline travels to a ledge below the [[Golden Gate Bridge]] (a familiar backdrop in Hitchcock's films) and jumps over the edge. Scottie follows her in, and saves her. He brings her back to his apartment to recuperate, they speak, and she returns home.