The film is based on a short story by Julio Cortazar, published in 1951. Its main theme is about perverse sexual gratification in a repressed Catholic environment. Delia Mañara is notorious in her quarter of Buenos Aires for the mysterious deaths of two of her fiancés. She lives in a twilight world and gains most satisfaction through the exercise of power over others. It emerges that she killed the two men by poisoning them with the sweets she makes; when this fails with her third fiancé, he is freed from her fatal attraction by the knowledge.