On the same day that Margaret Wilson joins the staff of Martha Washington School for Girls in Southern California, a miserable and taciturn Betsy Abel, who claims to hate her mother, is “committed.” Mrs. Nichols, the unsympathetic head of the institution, tells Maggie that Betsy, who she calls “the little criminal,” refuses to name the father of her illegitimate, two-month-old son. A twenty-three-year veteran of the institution, Nichols believes that the girls are beyond help, but Maggie empathizes with Betsy’s suffering and tries to comfort her. In her cottage dormitory, Betsy’s roommates welcome her into their fold and the maternal Trixie Budlong, the daughter of an absent sailor and recently deceased mother, tells Betsy that their motto is “Best buddies por vida .” The other girls have all suffered from broken homes, alcoholic parents and little love: the competent and helpful Ouisie; the undependable Joyce, who wants to be a movie star; mentally ill Cuckoo, who is prone to erratic behavior; and Greeneyes, who will be released in four weeks. Greeneyes is engaged to her paroled boyfriend, Cliff Munster, who plans to “stay clean.” Late that night, alerted by a written message Betsy brought in from the outside, Greeneyes sneaks to the fence to meet Cliff, who reports that he has a job with a trucking firm. On Sunday, Betsy’s alcoholic mother, Sally Abel, and Sal’s boyfriend, Ed, a taxi driver with a police record, visit her. While Ed cringes behind her, Sal pleads with Betsy to name the father so that he can be made to help pay for the baby, unaware that Ed fathered the boy. Irked by Betsy’s reticence, Sal threatens to send the baby to an orphanage. The eavesdropping Cuckoo, hearing Sal say that the unwanted baby is in the back seat of the car, “rescues” and hides him. Ed and Sal drive off without first checking on the baby and when they later discover he is missing, Sal tells Betsy that they found a nice home for him. When the other girls learn about the boy, they rally to prevent him from being sent to an orphanage. They also protect Cuckoo, who they assume will be sent to a mental asylum for kidnapping the baby. Although Betsy’s confused feelings about the child drive her to remain aloof, the others, touched by the unwanted child, organize themselves to watch over the boy, whom they name “Buddy” after their motto. Hiding him in the closet, they raid the pantry for canned milk and tear up sheets for diapers. The girls in the other dormitories also help hide his presence by singing to cover his cries and distracting the staff. Eventually, Betsy’s motherly instincts take over and she, too, takes care of him. Anticipating a “real Christmas” because the baby is there, the girls make gifts for him. The staff is mystified by the sudden high morale and good behavior of the girls. Although they are puzzled by missing sheets and canned milk, as well as the singing at unusual times, they are pleased to note that there has been no need for disciplinary actions, thus resulting in less work for them. Only Maggie can see the good in the girls and tries to interact with them. During a conversation, she tells them how she was left on the steps of an orphanage as an infant and was raised in an institution until she got a job at age sixteen. One day Maggie discovers Buddy and is torn between her responsibility and her sympathy for the plight of the child and the girls’ rare happiness. When she compromises by deciding to do nothing until after Christmas, the girls agree to turn him over the day after. However, during Maggie’s day off, Ouisie is seen by a staff member burying dirty diapers and, although Greeneyes tries to hide Buddy, she is caught and the baby taken away. Later when orphanage personnel drive away with the baby, Cuckoo screams to alert the girls. An institution-wide riot ensues, in which the girls destroy property and try to escape. After the police restore order, Nichols questions Greeneyes and Betsy, but neither will tell who originally abducted the child. Nichols extends Greeneyes’ term six months and then considers having Buddy taken from Betsy permanently. Although their pain is acute, both girls refuse to turn in Cuckoo. After confessing that she knew about the child, Maggie begs mercy from Nichols on behalf of the girls, recalling how they gained dignity by caring for the boy. Unmoved, Nichols claims that nothing can really change the girls. Maggie points out that Greeneyes has turned her life around and has plans to marry. When she argues that keeping Greeneyes another six months “will kill her,” Nichols says that only punishment achieves results and that the girls are “durable.” On Christmas Eve, Trixie’s father, a loving man who has moved to town to give her a home, arrives to pick her up. Greeneyes, unwilling to wait six more months, sends a note to Cliff through Trixie. That night, she climbs over the fence to freedom, where Cliff waits with a stolen car. Maggie and the girls gather around the Christmas tree, where Betsy unwraps their presents for Buddy and promises herself that next year, she and Buddy will have a real Christmas together. On the radio, they hear a news bulletin reporting that Cliff and Greeneyes were killed while trying to evade the police, who were pursuing their stolen car.