Jacob Harlon is a successful stockbroker living with his wife Katherine and son Joshua in California. Driving his wife and friends, Jacob unintentionally runs a red light, causing a collision; his best friend Tom is killed. Advised to take a plea deal, Jacob is sentenced to 16 months at the California Institution for Men in Chino.
Shocked by the brutality of prison life, Jacob heeds his lawyer's advice to stand his ground. He attacks an African-American inmate when provoked, drawing the attention of Bottles, the “shot caller” for violent white supremacist gang PEN1 (Public Enemy No.1). In return for protection and entry into PEN1, Jacob is forced to smuggle heroin and kill a "snitch" within the gang.