Upon his release from prison, James "Jimmy" Cullen gets his 1970 Chevrolet Chevelle, a gun, and a list of names. He goes to a telemarketing office in Bakersfield, California, where he kills Prescott Ashton. Next, he meets Roy Grone, who provided him with the car and gun, and pressures him for more names. Detectives Cicero and Humphries are on Cullen's trail; a hitman called "Killer" is also sent to eliminate him. Humphries struggles with heroin addiction and is close to retirement, which brings him full benefits. Cicero is competent but dislikes Humphries. She deduces from security footage that Prescott was familiar with his killer.
Cullen finds Kenneth Tyson, a snuff film maker, and kills him. Afterward, Cullen engages in a shootout with Killer but escapes. This encounter deeply impacts Killer, who becomes personally invested in the chase after proposing to his girlfriend, Lily. Killer, a perfectionist, overcame childhood polio through surgery and has never failed at anything, making Cullen’s success over him particularly frustrating. Humphries and Cicero look into Cullen's history and find out he was betrayed during a robbery. Cullen was the getaway driver, while Gary was part of the crew. He managed to escape due to his excellent driving skills. However, the crew got ambushed by another gang in a setup, which was captured on video. Cicero recalls a video of Gary's death filmed by Tyson, showing an unidentified man shooting Cullen, who barely survived and now has a metal plate in his head. The killers were not identifiable in the footage, so the case was closed. Cicero concludes that Cullen is targeting everyone shown in that video.
Cullen visits his ex-girlfriend, Nan Porterman, who realizes he's avenging those involved in Gary's death. She shares that she aborted their child and has moved on with her life, wishing him well. At a Nevada strip club, Cullen attacks bouncer Hovis Nixon for his connection to Gary's death, but Nixon survives. Humphries and Killer learn that Nixon is hospitalized and anticipate Cullen will return to finish him off.
Cullen enters the hospital and kills Nixon during surgery. Humphries tries to apprehend Cullen but is spared when Cullen sees his badge. While fleeing the hospital, Cullen is pursued by Killer, resulting in a high-speed chase where Killer shoots Cullen in the neck. Killer receives a call from his handler about canceling the job, but he refuses to back down. Cullen goes to his mother for stitches on his neck. He eventually suspects his father orchestrated the murder of him and Gary due to their refusal to share stolen money, but later learns his father died 3-4 years prior. Mrs. Cullen (Annie Corley) claims that Cullen's father wouldn't have killed Gary. Mr. Cullen was harsh towards Cullen because he was aware Cullen was born from an affair. Cullen notices a family photo highlighting Gary's girlfriend, who is now married to Humphries.
The last person on Cullen's list is traveling evangelist Alexander Jerrod (Adewale Akinnuoye-Agbaje). After his service, Cullen confronts him but spares him when Jerrod admits to changing his life and asks for forgiveness. Cullen is then approached by Killer, who tells him there are still unresolved matters regarding his employer. Cicero uncovers the identity of the man who shot Cullen. She discovers that all victims were police informants with minimal prison time, handled by Humphries.
She rushes to the church where Humphries is present. As Killer and Cullen face off, Humphries arrives and shoots Cullen in the head, revealing he was the one who shot him in the video. He offers Killer payment for the job, but Killer refuses and instructs Humphries never to contact him again. Humphries contacts his wife, Marina, who was secretly his informant while also dating Gary. Out of nowhere, Cullen shoots and kills him, having survived thanks to his metal plate. Cicero arrives after Cullen departs and conceals Humphries' actions.