Carvel judge James K. Hardy is confronted by banker George Benedict, who informs him that the judge's high school senior son Andy has bounced a check. The judge learns that Andy's check bounced because a check for fees signed by Steven V. Land, father of graduating seniors Kathryn and Harry, was not good. Soon discovering that the Lands are impoverished, the judge convinces the busy Andy to "hire" Kathryn to act as his secretary and give Harry the job of decorating the gymnasium. Steven, a well-educated former travel agent who fled Europe at the start of World War II, can only find work in a garage. In gratitude for Steven's help when Andy's jalopy breaks down in a rainstorm, the judge calls J. O. Harper, a friend in the state department, to try to get a job for the multi-lingual Steven. Mr. Benedict's daughter Polly, Andy's girl friend, is jealous of Kathryn, especially after she encounters Andy buying stockings for Kathryn to wear at graduation. As final examinations begin, the principal, Mr. Davis, announces that the governor is offering a $25 prize and a trophy to the student who gets the highest mark in English. Andy has a tough time with his final, while Harry breezes through. That afternoon, Steven learns that he has been offered a job in South America and must leave on Thursday, the day before graduation. Harry and Kathryn are happy about the job, but regret that they will miss commencement. When Andy realizes how disappointed they are, he secretly changes the date of the acceptance telegram from Thursday to Saturday. Later, when Andy gives Kathryn her gift, a telegram arrives from the state department stating that due to "the circumstances" the job offer has been withdrawn. The family is shattered. Andy asks Kathryn to come with him to his house and has a father-son talk with the judge, during which he confesses what he has done. The judge then explains that the exact date was very important because they were to sail in a group with a trade commission, but offers to contact Harper. The next day, Andy's aunt, Milly Forrest, who is his English teacher, tearfully reveals that he has failed his English exam and cannot graduate. Shattered, he goes home to tell his father, who angrily tells Andy that he was concentrating too much on graduation activities. Andy is so despondent that he wants to leave town until after graduation, but the judge says that he must face up to his failure. At a meeting the next day, Andy announces to the class that he is the only one not graduating and tenders his resignation to all of his committees. Harry, Polly and Kathryn try to console Andy, but he leaves, then sends his white flannel graduation pants to Harry, who cannot afford them himself. At the train station, Andy buys a ticket for the city and sadly watches workmen unloading the new car that the judge had ordered for him as a graduation present. Meanwhile, Harry and Kathryn show Aunt Milly that school rules allow students who fail a final exam to re-take it if their grades previously had been good. When Harry receives Andy's package he realizes that Andy is running away and goes to the station to bring Andy back. After Mr. Davis agrees to let Andy have another chance, Polly, Kathryn and Harry grill him all night, and the next morning he easily passes the exam. His happiness is marred, however, when the judge informs him that Mr. Harper has already hired a replacement for Steven. Andy then tells Kathryn, who has a beautiful singing voice, to sing a solo at commencement in place of his essay, which he now feels is hypocritical. The governor awards the graduation prize to Harry and, because he admires Harry's work decorating the gym, offers him a job as a window dresser in his brother's store. Finally, the governor appoints Steven as interpreter for the appelate court. Later, when Polly shows Andy what he thinks is his new car, he is chagrined to discover that it is really hers until the judge arrives in another one just like it.