S%C3%A9ance on a Wet Afternoon

Sance on a Wet Afternoon is a 1964 British film directed by Bryan Forbes, based on the novel by Mark McShane, in which an unstable medium convinces her husband to kidnap a child so she can help the police solve the crime and achieve renown for her abilities. The film stars Richard Attenborough who was also the films coproducer, Kim Stanley, Nanette Newman, Mark Eden and Patrick Magee.

At Myras insistence, Billy kidnaps the young daughter Judith Donner of a wealthy couple Mark Eden and Nanette Newman, confining her in a room in the Savage home dressed as a hospital ward. Myra impersonates a nurse to deceive the girl into believing she is hospitalised. Myra insists she is borrowing the girl to demonstrate her psychic abilities to the police in helping them find her. Although they ask for a 25,000 ransom, they plan to return the money with the girl after Myra has become famous for helping find her.Myras plan goes awry as her unsteady mental health begins to fray. She tells Billy to kill the girl, and he takes her into the woods and leaves her body under a tree. ........

Source: Wikipedia