Charles and Ruth Condomine await three dinner guests, one of whom is the celebrated medium Madame Arcati, who is to hold a séance after dinner. The purpose of this séance—although Madame Arcati is not told this—is to allow Charles to gather background material for his new thriller, The Unseen. While waiting, Ruth attempts to teach the new maid, Edith, some discipline and decorum. Conversation turns to the subject of Charles’s former wife, Elvira, who died of a heart attack brought on by a fit of uncontrollable laughter.

Ruth, who was also married before, claims that she does not mind in the least being thought less attractive than Elvira, although the manner in which she brings the subject up and Charles’s determination to avoid making any such judgment suggest that she does mind. It seems that Ruth feels that she is still, in some sense, competing with her predecessor for her husband’s affections. She suggests to Charles that he was dominated by women throughout his life and still remains under Elvira’s spell. He denies this but says that if it were so then Ruth is obviously the one presently running his life.

When the Condomines’ friends, the Bradmans, arrive, the discussion switches to the topic of Madame Arcati, whom all know only by sight and reputation. Charles is dismissive of her literary endeavors, which include fantasies for children and biographies of minor members of the royal families of Europe. Madame Arcati eventually arrives on her bicycle.

Before the séance begins, Madame Arcati puts the popular song “Always” on the gramophone because her spirit guide—a child named Daphne—likes music. The séance is rather chaotic to begin with, producing a good deal of table-rapping and an abundance of sarcastic remarks that begin to annoy the medium. Charles’s mood undergoes a dramatic change, however, when he hears Elvira’s voice speaking to him—a voice that, as becomes clear, no one else (except, of course, the audience) can hear. Madame Arcati faints, and when she regains consciousness everything seems normal. As soon as Charles shows her to the door, the conversation between Ruth and the Bradmans becomes casual again. They are unable to see the ghost of Elvira enter the room and sit down.

When Charles returns he joins in the lighthearted conversation. Not until the Bradmans have gone does he move to a position from which Elvira is visible. Because Ruth is unable to see or hear Elvira, Charles’s reaction to her presence and his subsequent dialogue with the ghost seems to be evidence of madness. Ruth soon stalks off to bed, leaving Charles to sleep in a chair.

When Charles awakens the next day he assumes that he was the victim of a hallucination. He almost makes his peace with Ruth when Elvira’s ghost strolls in from the garden. As misunderstandings multiply once again, Charles prevails upon Elvira to prove she exists by moving various inanimate objects. As soon as Ruth is convinced, she summons Madame Arcati with a view to exorcising the ghost, but the medium is not at all certain whether this can be done.

The problem becomes urgent when Ruth becomes convinced that Elvira is trying to kill Charles in order to secure a permanent reunion on equal terms. Charles is initially skeptical about Elvira’s murderous intentions, in spite of her constant sniping at Ruth. He is, however, forced to see the truth when one of Elvira’s traps catches the wrong victim and kills Ruth instead of him.

At this point Elvira decides that perhaps she would be better off where she came from. Madame Arcati manages to locate a...