The Score is based on an autobiography written by an ex-convict, describing his prison experiences.

A group of youths, high on drugs, steal a car and try to hold up a bank with a toy pistol. Their attempt fails; the police testify the gun was real, and the boys receive a four year sentence.

The film opens with the last two weeks of Kennet Ahl's term. Though still aggressive, with the help of an older prisoner, who befriends him, he is trying to reform, hoping for a normal life with his girlfriend, Karin, when their expected child is born.

When he is released, Kennet goes to Karin's home, but her father fails to give him a promised job in his driving school. Karin puts pressure on her father, and Kennet is found a job in which he succeeds, and a flat in which they live.

Then, without warning, or explanation, the police seize him again. It turns out that his arrest was due to a mistake, but red tape prevents his release for weeks. He vents his frustration in a violent outburst, the prison authorities put him in solitary confinement. When finally released, Kennet finds that Karin in despair at being unable to find out what had happened to him, had attempted suicide, and gave birth to the child prematurely. At the hospital Karin and her parents reject Kennet; he attacks the father, and he is returned to prison. He escapes with his former prison friend; they visit a drug pedlar they knew, but find him dead from an overdose, with a large stock of drugs with him. They take the drugs, but Kennet is persuaded to give himself up, He does so, and reforms in prison. After a reconciliation with Karen, he hopes that, when he is finally freed, he will be able to lead an honest life.