Bradley Thomas is laid off from his job at an auto repair shop. When he arrives home, he finds a hickey on his wife, Lauren, who admits to an extramarital affair. Bradley orders her inside the house before he violently dismantles her car. He later discusses with Lauren their failing relationship, forgives her, and turns to drug trafficking.

Eighteen months later, Bradley and a now-pregnant Lauren have adjusted to a better life. Bradley’s boss, Gil, introduces him to Eleazar, a new business associate, with a task to pick up a package of crystal meth with two of Eleazar’s men. Bradley distrusts one of Eleazar’s henchmen, Roman, but accepts the job when Gil offers him three months’ paternity leave. During the job, Bradley realizes it is a police trap and orders Eleazar’s men to ditch the drugs. However, Eleazar’s men ignore him and exchange fire with the police. Bradley, hesitant, attacks Eleazar’s men; one of the men is fatally shot by the police while Roman is incapacitated. The police detain Bradley alive. Unwilling to give out names, Bradley is sentenced to seven years in a medium-security prison.

During the night, Eleazar’s men kidnap Lauren. In prison, Bradley is visited by the Placid Man, a henchman for Eleazar. The Placid Man commands Bradley to assassinate an inmate who is held in Cell Block 99 at Redleaf, a maximum-security prison. If Bradley refuses, the limbs of his unborn child will be surgically removed and sent to him. Bradley reluctantly accepts and fights multiple guards in order to be transferred to Redleaf.

At Redleaf, Bradley meets the authoritarian warden Tuggs, who demeans him and sends Bradley to a dilapidated cell. He learns that Cell Block 99 is for society’s most despised criminals. Bradley starts a brawl with other prisoners in order to be reassigned to Cell Block 99. After he is reassigned, Bradley learns that his assassination target does not exist.

During the night, a Redleaf guard escorts Bradley to another cell, where Eleazar and his gang, including Roman, are held. They intend to torture Bradley for their amusement throughout his incarceration at Redleaf. Bradley ambushes the guards and brutally kills most of Eleazar’s gang. Eleazar calls the doctor to carry out Eleazar’s threat and harm Bradley’s unborn child. Bradley tortures Eleazar until he calls off the operation.

The Placid Man and the doctor follow Eleazar’s orders and drive Lauren unharmed to Gil’s house. As they drive away, Gil retrieves a hidden rifle and kills the Placid Man. Lauren takes the rifle and shoots the doctor. Gil phones Bradley to inform him that his family is finally safe, and Bradley speaks to Lauren about their unborn child. Bradley then decapitates Eleazar in his cell. Tuggs and his guards emerge and the warden executes Bradley with his revolver.