Vice Squad Sergeant Sam Hanlon brings 17-year-old Susan Landis 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.