The film begins with a tense scene where a woman named Lydia (played by Erin Moriarty) purchases bullets from a local store. Shortly after, she gets into a vehicle with her boyfriend, Jonah (portrayed by Diego Luna), and several men who seem equally involved in a troubling situation. The men prepare for an unsettling task, loading their weapons as they drive to a rented house. Here, Jonah, who has seemingly hired these men for muscle, intends to confront the occupants of the house, where he believes drug money has been hidden. His anger is palpable as Lydia exhibits visible anxiety about the impending confrontation, prompting him to offer her a line of cocaine to take the edge off, suggesting she keep an eye on the children playing in the backyard.
While keeping watch, Lydia is suddenly jolted by the sound of gunfire. Rushing inside, she discovers a grim scene: a man lay dead on the floor, and a woman is tied up in a corner. Jonah is above her, demanding to know the whereabouts of his stolen money. Lydia desperately pleads for the woman's life, but Jonah is unyielding and continues his intimidation. In a moment of chaos, Lydia unintentionally shoots Jonah in the neck, leaving him gravely injured. She escapes the house just as his men hear the commotion and rush in to help him.
Meanwhile, miles away, Lydia's father, John (played by Mel Gibson), is introduced as an ex-con recently released on parole. He shares his experiences during an Alcoholics Anonymous meeting with his sponsor, Kirby (William H. Macy), and later retreats to his trailer, which doubles as his tattoo parlor. Suddenly, Lydia’s call interrupts his quiet evening; she reveals that she is in deep trouble and informs him of her location in Santa Monica.
After picking her up, John takes her back to his place where she, coming down from her drug and alcohol high, quickly falls asleep. As days pass, John notices Lydia's erratic behavior: one moment she's calm and collected, the next, she's hyper and talkative. Concerned, he checks her purse and discards the drugs he finds inside.
Their lives take a dangerous turn when gang members arrive at John's trailer. He confronts them, claiming he's closed for business, but when they start shooting, both he and Lydia are forced to take cover. Amid the chaos, John stabs one of the gang members and, with the help of his neighbors, successfully fends them off. With police sirens approaching, they escape, but not without tension.
The very next day, Lydia confides in John about the events that led to the death of Jonah. They stop at a motel to rest, but when Lydia sneaks out to speak with the clerk, she discovers that the police are on their way. They manage to evade capture, but just as they think they are safe, violence erupts—a cop is killed.
Desperation escalates as John reaches out to an old friend, Preacher (played by Michael Parks), hoping for help. However, betrayal lurks as Preacher aims to cash in on the reward for turning them in. After a violent confrontation, John makes a narrow escape with Lydia.
Their journey becomes a harrowing fight for survival, facing professional assassins and navigating highway shootouts that test their resolve. John learns from a friend in prison that Jonah was implicated in stealing from the drug operations, complicating their predicament. The stakes intensify when Lydia is kidnapped, and John is forced to confront Jonah again.
In a gripping showdown in the desert, John cunningly places a landmine on his motorcycle as a trap for Jonah's men. During the chaotic confrontation that follows, John showcases his fierce determination and resourcefulness, managing to free Lydia while confronting Jonah in a violent struggle. Tragedy strikes as John receives multiple gunshot wounds during the melee, ultimately sacrificing himself for Lydia's safety.
As police arrive, John's legacy becomes clear, leaving behind a love that Lydia deeply cherishes. In a poignant closing scene, she reflects on their journey at an AA meeting, sharing her struggles and how she draws strength from his memory, stating, > "I've been sober a year, but I miss my Dad so much that sometimes I can't sleep at night, but I tell myself that he's watching over me. Sometimes, there's this shame that almost breaks my back, but I tell myself, when you owe your life to someone, you better live it... So I just say thank you." The screen fades to black, encapsulating the enduring bond between father and daughter amidst the turmoil.
