On the night that presidential nominee Dewey Roberts is to speak at a banquet at the Mayflower Hotel in Washington D.C., elderly teacher Nora Trinell arrives to wish him luck, for Dewey is one of her former pupils. As she listens to the band playing Dewey's favorite song, "(Back Home Again in) Indiana," Nora reminisces about when they met in Indiana on 14 Apr 1916: Nora is a new teacher taking over Dewey's class, and she dismays the headstrong young boy by announcing that she will be taking the class to a play matinee on the same day that he is to pitch in an important baseball game. Dewey appeals to his coach and manual training instructor, Dan Hopkins, who in turn asks Nora to postpone the matinee. Although Nora does not appear to be swayed, she and Dewey do find a common interest in boats and resolve to become friends. Nora does let Dewey play in the game, which she attends with Kate Hill, another of her pupils, who likes Dewey. Dewey's knee is injured in the game, but Nora visits him at home to continue his education. Nora gently guides the boy into becoming more studious and living up to his potential, and he soon develops a worshipful crush on her. Meanwhile, Dan also becomes enamored of Nora and pursues her. At the semester's end, Nora goes with the other women teachers on a summer holiday, but is soon bored and is very happy when Dan turns up one afternoon. Nora spends the rest of the summer at Avery Farm with Dan, and the two fall deeply in love. When school resumes in the fall, Nora and Dan decide to keep their relationship a secret and marry at Christmas. Dewey, who has refused to go away to prep school so that he may remain near Nora and play football for Dan, builds a sailboat modeled after one in the picture postcards of Avery Lake that both Dan and Nora sent him. Mr. Steele, the school's principal, sees the postcards and assumes that Dan and Nora spent the summer together having an illicit love affair. Wishing to spare Nora's reputation, Dan agrees to resign but asks Steele not to tell Nora why. After Dan tells Nora that he resigned in order to get a better job, he goes to Chicago, and autumn quickly passes. At Christmas, Dan returns in uniform and tells Nora that he has joined the Royal Canadian Engineers. Because Dan must go overseas in two weeks, Nora decides that she wishes to marry him immediately, and the couple spend an idyllic honeymoon at Avery Farm. After welcoming in 1917 together, Dan and Nora return to the school, where Dewey, after seeing them kissing, feels that they have betrayed him. Heartbroken that Nora could love someone else, Dewey decides to go to boarding school and is about to leave without saying goodbye to Nora when she comes to his house. Nora explains to the boy that although he is very special to her, she loves Dan. Inspired by her words of encouragement, Dewey happily boards the train, which also carries Dan, and the pair wave goodbye to Nora as they leave the station. After her reminiscences, Nora finds another of her former pupils, Bill Tower, who is now a bellboy at the hotel. Bill sneaks Nora into Dewey's office, but Dewey does not recognize her as she tells him how proud she is of him. In the elevator, however, Dewey remembers Nora and sends a hotel detective to find her. Dewey and Kate, who are now married, warmly welcome Nora, and Dewey tells Kate that all those years ago, on the train, Dan told him that he and Nora were married. Nora quietly informs them that Dan was killed in France, then attends the banquet with Kate. As the applause for Dewey swells, Nora proudly tells Kate that he was always a good boy.