Patty Bergen is twelve years old and school is out for the summer in her small Arkansas town where nothing much ever happens - that is, until this summer, when a prison camp for German prisoners of war captured during World War Two is opened and the first prisoners arrive. The town is briefly fascinated by them, but for Patty the fascination endures. She hopes that telling her father about the prisoners' arrival will get his attention and please him but although he is interested he is still as disdainful of her as ever. Patty is excited when the prisoners come into the department store her parents own whilst she is there; she jumps onto the register to help and meets gentle, polite Anton Reiker who is looking to buy a pencil sharpener. She is immediately struck by his manners and finds him easy to speak to; she is also surprised when he buys a rather cheap-looking pin with imitation diamonds that are a bit too shiny, that seems like something he would never buy. There is a definite and immediate connection between Patty and Anton.
The next time she hears Anton's name it is on the lips of everyone in town, as he escapes from the prison. Nobody can quite understand how he is able to get away and the FBI is brought in to investigate. The local sherrif questions Patty as it was she who helped him in the store and perhaps he let something slip about his escape plans. She also talks to a reporter named Charlene Madlee who is convinced Anton had inside help at the prison. Patty rides along to the prison with Charlene after telling her she wants to be a reporter when she is older. They speak with all of the guards but cannot find any explanation for Anton's seemingly easy escape.
With a prisoner on the loose Patty is not allowed out in the street anymore but luckily has the secret room she has renovated above her parents' garage. This is also where Anton is hiding out, and rather than being scared to see him Patty is actually relieved. She begins taking food from the kitchen to give to him; she also takes some clothes from her father's closet, giving him the very expensive monogrammed shirt she had given her father in an attempt to make him feel some kind of love for her; it hadn't worked and the shirt remained in its gift box. Anton and Patty enjoy each others company and get to know each other in secret, finding that they both feel lonely, isolated and frightened. Anton tells her that the cheap pin he bought from her parents' store was the key to his escape as he had told one of the guards the pin was valuable and genuine diamond, which meant that the guard was happy to turn a blind eye to his escape in return for the pin.
One evening as Patty's father is shouting at her for another perceived transgression he begins beating her with his belt, a regular occurrence, and as she is on the ground she sees Anton who has come from his hiding place to defend her; she frantically gestures him to go away so that he does not give himself away and he goes back to the secret room again but not before Ruth, the Bergen's housekeeper Ruth has seen him.
Ruth, who loves Patty like her own daughter, questions Patty about the prisoner and Patty tells her the truth. Aware he will be hungry, Ruth makes a large breakfast and invites Anton into the kitchen to eat it. They talk easily and Ruth talks about her son who is fighting in Europe. Patty's father comes home early from work and Anton only just makes it into the secret room without being seen, making both Ruth and Anton aware that he needs to move on. Patty makes up her mind to go with him but he will not agree to this. He gives Patty a treasures ring that is a family heirloom which she hides for safe keeping.
Once Anton has left Patty misses him deeply and imagines meeting him again someday. A couple of weeks after he has moved on her father comes home accompanied by an FBI agent who questions her about Anton. She talks mostly about their meeting at the store but the agent tells her they know she assisted him because when they captured him he was wearing the monogrammed shirt that her father has already identified. When the agent shows her the shirt there is a bloodstained bullet hole in the chest area which is how she finds out Anton was shot and killed in New York; she becomes almost hysterical.
Patty is arrested and sent to a reform school but the lawyer her father appointed to defend her really did nothing but tell Patty not to tell her story. Her only visitor in reform school is Ruth. Patty vows that the moment she is eighteen she will leave home and never have to endure her father's abuse again.
