Mark Christopher (Powell) is a successful thirty-five-year-old Hollywood screenwriter who has suffered from partial writer's block since winning an Academy Award and has been unable to produce a decent script. One Christmas Eve, he receives an unexpected and very unwanted surprise present.
Vice Squad Sergeant Sam Hanlon (Herb Vigran) brings seventeen-year-old Susan Landis (Reynolds) to Mark's luxurious apartment. Susan had been abandoned by her mother and was arrested for vagrancy and hitting a sailor over the head with a beer bottle. Not wanting to keep her in jail over the holidays and aware that Mark was interested in writing a script about juvenile delinquency, the kindhearted cop decides to bend the rules (much to the disapproval of his partner). Hanlon suggests that Susan stay with Mark until her arraignment the day after Christmas.
Mark is naturally appalled, but is eventually persuaded to take the girl in. This doesn't go over too well with his long-time fiancée, Isabella Alexander (Anne Francis), the demanding daughter of a U.S. Senator. Isabella's jealousy grows when Susan develops a crush on Mark. Mark's secretary Maude Snodgrass (Glenda Farrell), his best friend Virgil (Alvy Moore), and his lawyer Harvey Butterworth (Les Tremayne) do their best to keep the situation under control.
When Harvey lets slip that Susan will likely stay in a juvenile detention facility till she is 18, Mark impulsively takes her to Las Vegas and marries her. The marriage, he explains to his friends, will last for just long enough to convince the judge that Susan has made good. To avoid consummating the marriage, he takes Susan out dancing till she collapses with fatigue, and brings her back to Hollywood.
Mark then slips away to a cabin in the Sierra Nevada mountains to work on his script with Maude. The marriage is reported in the newspapers. Enraged Isabella confronts Susan, but is hauled away by Hanlon and his partner.
Some weeks later, Isabella finds Mark in the cabin. She has calmed down, but Mark says he thinks they are not really suited to each other. Susan also arrives, determined to win Mark to a real marriage. She is encouraged and supported by Maude, who still regrets leaving her childhood love behind for an attempted acting career in Hollywood. Susan refuses to sign the annulment papers, while Mark still will not consummate the marriage.
When Susan is seen eating strawberries and pickles, Mark's friends assume the worst: that she is pregnant. Susan eventually confesses to Mark that she just likes that combination. Mark has his own confession: he is in love with Susan but is worried by their age difference. Susan tells him all the reasons that they should stay married and pulls him into the bedroom.Dick Powell as Mark Christopher
Debbie Reynolds as Susan Beauregard Landis
Anne Francis as Isabella Alexander
Alvy Moore as Virgil, Mark's assistant
Glenda Farrell as Maude Snodgrass
Horace McMahon as Sergeant Monty Maizel
Herb Vigran as Sergeant Sam Hanlon
Les Tremayne as Harvey Butterworth, Mark's lawyer
Mara Lane as Marilyn, Mark's neighbor
Maidie Norman as Georgette, Mark's maid
Rita Johnson as Dr. Rawley, Harvey's psychiatrist
Ellen Corby as Coffee Shop Waitress
Benny Rubin as Sylvester the janitor
Barbara Darrow as Miss Jennings, Dr. Rawley's secretary
Sue Carlton as Coffee Shop Cashier
Reynolds later admitted having "a mad crush on" Dick Powell. "He taught me common courtesy and to treat my crew and colleagues with equal respect."
Reynolds liked the film later stating "that little comedy made $5,500,000, pulled RKO out of the red and then Howard Hughes sold the studio".
The film was nominated for two Academy Awards, for Best Music, Original Song "Hold My Hand" (sung by Don Cornell), and for Best Sound, Recording (John Aalberg).