A young man joins forces with a judge in an effort to reconcile his parents' broken marriage.

Traveling with his mother Evelyn on the train on his return from camp, twelve-year-old Christopher Blake dreams that he has developed a plan for world peace. As the train arrives in Los Angeles, Chris asks his mother if his father Ken will be there to meet them, but she avoids answering his question. When Chris continues to press her, she replies that Ken is out of town. After Evelyn goes upstairs for a nap, however, Ken arrives at the house. He starts to tell Chris something, but ends by agreeing to stay home for Chris's birthday. After Chris is in bed for the night, Evelyn demands that Ken tell Chris about their separation and pending divorce. Although Ken asked for the divorce when he fell in love with a sculptor named Ruth, he no longer is sure that he made the right decision. Evelyn, on the other hand, is too hurt by the knowledge of his affair to reconcile. The next morning, Chris asks to accompany his mother to her lawyer's office and accidentally learns about the divorce from the lawyer's secretary. When Ken and Evelyn are unable to reach an agreement as to which parent will have custody of Chris, the lawyers reply that Chris will have to make that choice himself. On the day of Chris's thirteenth birthday, Ken is not present, but Evelyn reassures Chris that both she and his father love him and want him to love both of them. Later, Ken takes Chris to a play during which Chris falls asleep and dreams that he is a great playwright, who authors a play about divorce. Afterward, Chris and Ken spend some time together at their lakeside cottage. In response to Chris's questions, Ken tells his son about Ruth, and that night Chris has a dream in which he begs Ruth not to break up his parents' marriage. When Ken drops Chris off at Evelyn's, he again begs her to call off the divorce for Chris's sake, but when he fails to say that he loves her, Evelyn sends him away. Chris then dreams that he is being honored for developing an atom bomb and a world peace plan, when he is shot by John Wilkes Booth, and that his sorrowing parents are reunited over his body. At the Blakes's divorce hearing, the judge questions a teary Chris, who cannot make a decision about who will care for him. Later, while the judge speaks privately with Chris, Ken apologizes to Evelyn for his behavior and adds that he still loves her. After Chris tells his mother that he has chosen to live with his father and then tells his father that he has chosen to live with his mother, both parents realize that they are going to lose the most important person in their lives and reconcile.