John Binkerson ("Binx") Bolling is a young man from a "good" New Orleans family who for some years has devoted himself to money, sex, and watching movies. During Mardi Gras, when the novel begins, he wakes up to the vague feeling that something more is needed in his life.

We meet his Aunt Emily, a Southern noblewoman, and his cousin Kate, who is said to be somewhat unstable since her fiance's death some years earlier; she is currently engaged to the virtually invisible Walter. The action also takes us to the bayous, where Binx visits his remarried (Catholic) mother and her family, including his sickly adolescent stepbrother, Lonnie. (Binx's father died in World War II; Binx, himself, has survived service in the Korean Conflict.)

Subsequently, Binx takes a trip to Chicago with Kate; on the train she offers to have sex with him, but he refuses. Binx and Kate must then respond to Lonnie's unexpected death. In the end Binx decides to give up his business as a bond dealer and go to medical school, and he and Kate decide to marry.