"The Postman Always Rings Twice" is a novel by James M. Cain, published in 1934. It tells the story of a drifter named Frank Chambers who becomes involved with a married woman, Cora Smith, at her roadside diner. Their passionate affair leads them to plot the murder of her husband, Nick Smith, to be together. The narrative explores themes of desire, betrayal, and moral ambiguity. The title symbolizes the inevitability of fate and consequences, as the characters' actions ultimately lead to tragic outcomes. The novel has been adapted into several films, highlighting its enduring impact on American literature and cinema.