At her father's funeral, Ann Chapin thinks back over the last five years of his life, years of apparent political and personal failure dominated by a selfish and dissatified wife and eased only by alcohol. But it starts to emerge that there was in fact one brief and unsuspected period of happiness and love.

In Apr 1945, outside Ten North Frederick Street in Gibbsville, Pennsylvania, a newscaster reports on the funeral of prominent attorney Joseph P. Chapin. As the governor, district attorney and other dignitaries file into the house, Chapin's widow Edith addresses the gathering. While the cold-blooded, selfish Edith eulogizes the man she never loved, her son and daughter, Joby and Ann, wonder why their father lost his will to live. Ann's memories return to a happier time, five years earlier, at Joe's fiftieth birthday party: After a night of celebration, Ann, Edith and Joe return home to discover that Joby has been expelled from boarding school. Although Joe expects Joby to follow in his footsteps and go to law school, Joby dreams of attending music school and playing jazz piano. Ann, the perfect "daddy's girl," defends her brother's decision, while Edith fears what others would think if their son became a musician. Edith is politically ambitious, and so prods Joe to enter the race for lieutenant governor, a post his grandfather once held. To win the nomination, Joe pays $20,000 to Mike Slattery, a corrupt power broker. One day at a fair, Ann spots handsome trumpet player Charley Bongiorno and brazenly introduces herself. The brash Charley cavalierly invites the naïve Ann for a drink, and during the band's intermission, they climb into the back seat of a stranger's car and passionately kiss. The car's owner abruptly interrupts their romantic interlude, and throttles Charley. Soon after, Slattery visits Joe to show him a newspaper column criticizing his candidacy. Ann, distraught, tries to speak with her father, but Joe, preoccupied with his campaign, hurries away to a business dinner. In desperation, Ann turns to her mother and confides that she and Charley are secretly married and are expecting a baby. Unsympathetic, Edith pronounces Charley unsuitable and castigates Ann for damaging her father's political chances. When Edith suggests an annulment, Ann becomes hysterical. After Slattery and district attorney Lloyd Williams, a family friend, convince Joe to let them handle the situation, they convene in Slattery's office, where Joe mutely watches as Charley is offered a check to annul his marriage. When Charley balks, Lloyd threatens to charge him with statutory rape, as Ann is under eighteen, and intimidates him into accepting the money. Soon after, Ann suffers a miscarriage, and when she calls for Charley, Joe informs her that Charley accepted a bribe to annul their marriage. Repulsed, Ann decides that she must leave home and moves to New York City. When the party power brokers refuse to back Joe, fearing that Ann's pregnancy may create a scandal, Joe decides to withdraw from the race, bitterly disappointing Edith. After Joe returns home from a night of drowning his sorrows, Edith accuses him of being with another woman and cruelly reveals that she had an affair with Lloyd fifteen years earlier. She then declares that she has wasted her life on him, a failure. Despondent, Joe begins to drink heavily. During a business trip to New York, Joe goes to visit Ann and is greeted by her roommate, young model Kate Drummond. In Ann's absence, Joe confides to Kate that he feels guilty for destroying his daughter's happiness. When Kate responds sympathetically, Joe invites her to accompany him to the theater. At a nightclub after the play, Joe encounters Paul Donaldson, a womanizing acquaintance from Gibbsville, who leers at Kate. The night he spends with Kate rekindles Joe's desire to live, and when Kate returns home that evening, Ann senses that she has a new man in her life. While Ann and Joby vacation in Bermuda over Christmas, Joe seizes the opportunity to visit Kate. Realizing that they have both fallen in love for the first time in their lives, Joe drives Ann to a secluded mountain cabin and presents her with a ruby that once belonged to his grandfather. When Kate suggests that they need to be discreet about their affair, Joe replies that he intends to divorce Edith and marry Kate. That night, while dining at a restaurant, Joe's ardor is dampened after a group of Kate's friends mistake him for her father. Unable to deal with the vast difference in their ages, Joe breaks off the romance. Five years later, Joby, now a soldier, comes home from war after he is notified by the family doctor that his father is gravely ill. Joe, now a hopeless drunk, declines all medical help, and Edith selfishly refuses to intervene on his behalf. After Joby tells Ann that their father is suffering from a case of "galloping despair," she agrees to return home for the first time in five years. When Joe asks Ann about Kate, Ann, unaware of their affair, replies that Kate is about to be married, although she never got over her first love. After Ann leaves the room, Joe recalls a conversation he had with Kate, then loses consciousness and dies. Ann's thoughts return to the present when Joby drunkenly decides to address his father's mourners and accuses Slattery of betrayal and Edith of murder. As Joby eulogizes Joe as the last Chapin of Frederick Street, Ann wishes that Joe had been able to savor one small victory in his years of defeat. Some time later, at Kate's wedding, Ann is helping pack Kate's bags when she finds the ruby and realizes that Joe was Kate's true love. After Ann tells Kate that Joe asked about her on the night he died, they begin to walk down the aisle.