Franz “Fox” Biberkopf, a working-class carnival worker, faces a sudden change in fortune when he wins the lottery. With newfound wealth, he becomes entangled with a circle of sophisticated, yet morally dubious, upper-class individuals. Fox meets Eugen Thiess, an elegant and cunning antiques dealer, and the two develop a romantic relationship. Eugen introduces Fox to his family and social circle, where Fox's lack of polish and naivety stand out. Despite his rough edges, Fox is eager to fit in and willingly indulges in their lifestyle, often at considerable financial cost.

As Fox becomes more deeply involved with Eugen and his affluent friends, he starts to spend extravagantly, striving to gain acceptance and recognition. His blind trust in Eugen gradually leads to manipulation and exploitation, revealing a stark divide between his innocent optimism and the cynical opportunism of those around him. This evolving dynamic highlights themes of class disparity, exploitation, and the sometimes harsh realities of love and trust in a socioeconomic context. As the story progresses, Fox's journey takes him through experiences that challenge his perceptions and his place within this new world of high society.