Act I
Monica, the daughter of Madame Flora (Baba) and Toby, the mute boy living with them, are playing while Flora is away. As she returns, she is furious that they are not yet ready for the seance she has planned. Monica prevents her from striking Toby. They all busily prepare and when the three guests arrive to the seance, Monica pretends to be the dead teenage daughter of Mrs. Nolan and then the baby son of the Gobineau couple, while Toby works the lights and furniture in the room. Suddenly, Madame Flora stops the seance and sends the guests away. She tells Monica she felt a spectral hand clutch her throat during the seance. Flora suspects Toby at first but as Monica tries to comfort her, Flora hears a voice imitating Monica’s performance of the dead baby boy at the séance.
Act II
A few days later, Monica is watching Toby perform a puppet show for her and then she dances for him. Monica realizes he is trying to tell her that he loves her but cannot actually pronounce any sound. Pretending to be his voice, she says it for him. Monica runs off as Flora returns and the elderly woman tries to make Toby confess it was him who touched her during the seance, or that he at least knows something about it. As he fails to answer, Flora begins hitting Toby but is interrupted by the entrance of the three clients coming for another séance. Flora gives them their money back and tries to convince them that she has cheated them but they refuse to believe, after all they did hear the voices of their dead children. Flora throws them out and despite Monica’s protests throws Toby out too. Monica leaves and Flora, frightened by what she has experienced, drinks herself to sleep. Toby returns and as Flora awakes he hides from her. Flora, thinking she saw the spirit she felt, shoots him.