This is a very long and complex storyline.
The boy returned is NOT Christine's son. Her son was kidnapped and held prisoner at a ranch where he was supposedly murdered by a serial killer. The killer is captured, tried, and sentenced to death. The police team that presented Christine with a false son is exposed, and the superiors relieved of their positions. Many years later, another of the killer's supposed victims is found to be alive, and tells how Christine's son helped him to escape. Christine does not give up the thought that her son is still alive, but at least has hope that he is still eager to return home.
Christine Collins reports her son Walter missing. The police investigate and five months later recover a boy abandoned in a restaurant several states away. Christine immediately recognizes the child as not her son, but the boy and the police protest otherwise. At home, Christine finds distinct characteristics that mark the boy an impostor. Interested only in the recovery of her real son, Christine goes to the police. Police captain JJ Jones insists that the boy is her son, and sends a doctor to explain how things may change over a period of five months for a boy his age. Christine continues to deny the boy's identity, but at the same time maintains her responsibilities as his caretaker. When he calls her "mommy," Christine becomes very upset and takes him to the family dentist and her son's schoolteacher, who both adamantly agree that the boy is no relation to her.
With the help of Reverend Gustav Briegleb, Christine goes to the press. To prevent an issue from occurring, Captain Jones has Christine locked up in the mental ward of the county hospital, where she meets other perfectly sane women whose only mistake was to oppose the police. When Christine tells the doctor in charge that there is nothing wrong with her, the doctor insists that the only way she will be set free is if she signs a form saying that the boy is her son. She refuses.
Outside of town, Detective Ybarra investigates the warrant for the arrest of an illegal teenage Canadian alien. Before Sanford is to be deported, he begs to speak to the detective. Sanford tells the detective how his cousin Gordon forced him to kill at least 20 boys they abducted together. Among the photos of missing children Ybarra shows him, Sanford identifies Walter, Christine's son. Ybarra has Sanford bring them back to Gordon's ranch, and identify the place where the bodies were buried, and he digs up the bones of at least one boy. Ybarra then calls in the investigation, exonerating Christine.
Reverend Briegleb storms into the mental ward and forces the release of Christine, who continues to protest that her son Walter is still alive, despite reports of his murder. In Canada, Gordon is arrested at his sister's house, and returned to California for trial. At the same time, the police department is investigated for improper handling of citizen reports. When told that he would be charged as an accomplice after the fact to Walter Collins' murder, the impostor child confesses. The lawyer for the case also has all women released who were incarcerated under the police "code 12" to have them testify in open court.
When tried, Gordon suggests that he was framed the same way Christine was framed. For the murder of the children, Gordon is sentenced to death by hanging. In the civil case, police captain Jones is put on permanent suspension, and police chief Davis is forced to resign.
Two years later, Christine receives a telegram from Gordon saying that if she visited him, he would tell her the truth about how her son died. When confronted, Gordon says that he cannot lie to her, and never says anything about her son Walter. Christine stays the extra day and bears witness to Gordon's execution, still sure that he did not murder her son.
Three more years later, the parents of another of the missing boy call Christine. Their son came home. The last scene is their son telling detective Ybarra how he, Walter, and another boy managed to escape Gordon's farm. He never saw Walter or the other boy after that. More important, he says that Walter ran back to help him get out, and that he owes his life to Walter. Christine never gave up looking for her son, but gained hope when she found out that he escaped, and was probably still eager to return home.
Herbert also adds...
"A lot like LotR RotK, in that there are parts where you say, "so the movie is over now...no...well, I wanted to see how that ended anyway."
***1/2 out of four. Comparing this to Mystic River, I don't like Clint Eastwood's interest in mutilating children."