Gavin: “Do you believe that someone out of the past, someone dead, can enter and take possession of a living being?”
Gavin Elster asks Scottie this question in his attempt to hire Scottie to trail his wife. Elster is referring to his belief that the long-dead Carlotta Valdes has taken possession of his wife, Madeleine. For the first two-thirds of the film, both Scottie and the viewer come to believe that it is indeed possible for someone dead to take possession of a living being, as Madeleine glides around San Francisco apparently haunted by Carlotta, even driven to suicide by her ghost. But Madeleine is not the only one in the film possessed by a dead person. After Madeleine’s apparent suicide, Scottie, too, becomes possessed. As he wanders about the streets of San Francisco after her death, he is continually convinced that he sees Madeleine in other women. When he meets Judy, he is certain that he has found her.
Judy also spends much of the film possessed by a dead person. The Madeleine whom she impersonates comes back to “haunt” her when Scottie insists that she assume the dead Madeleine’s identity in both appearance and behavior. Eventually, Judy loses herself to a kind of possession by the dead woman. As Scottie drags her up the stairs of the bell tower at the end of the film, Judy answers sometimes as herself, sometimes as Madeleine, no longer certain of her true identity. When she sees the shadowy figure of a nun at the top of the bell tower, she panics and falls, fearing the apparition may be the dead Madeleine returning to avenge her murder.