Major Charles Rane, played by Tommy Lee Jones, returns to a drastically altered San Antonio after being imprisoned as a POW in Hanoi for seven long years. His homecoming is bittersweet, as he grapples with a changed life where his son, Mark, has matured without him, and his wife, Janet, now has feelings for local policeman Cliff Nichols. Despite her lingering affection for Rane, a silent longing remains between them. With unwavering resolve, Rane aims to rebuild his relationship with Mark, strictly adhering to the disciplined mentality developed during his captivity. During the extravagant homecoming celebration, he is honored with a Cadillac and 2,555 silver dollars – each representing a day of his harrowing ordeal, with an extra token from Linda Forchet, a spirited Texan who kept Rane's ID bracelet close throughout his struggles in Vietnam. Although she shows interest in Rane, he finds it difficult to respond to her advances.
As Rane ventures through the streets, he unwittingly attracts the attention of four rugged outlaws – "The Texan," "Automatic Slim," "T-Bird," and "Melio." Having witnessed Rane's triumphant return on television, they schemed to seize his newfound fortune. Haunted by the trauma of his past, Rane faces a brutal confrontation when the gang resorts to torturing him, brutally damaging his hand. In a desperate bid to protect his father, Mark ultimately hands over the silver dollars, but the gang responds with merciless violence, leaving the family shattered and broken. Though Rane survives, the scars of that day run deep, and Janet and Mark are forever changed.
As Rane recuperates in the hospital with Linda and Master Sergeant Johnny Vohden, he ponders the heavy burden of his uncertain future. Vohden's choice to re-enlist in the Airborne Division serves as a stark reminder of what Rane has lost. He keeps secrets from Cliff, intentionally withholding the names of those responsible for his torment. His deeply rooted fury brims just beneath the surface, anticipating the day he can exact his revenge.
Upon his release, Rane prepares for his quest for vengeance, meticulously disassembling the double-barrel shotgun that Mark and Cliff gifted him, while adapting to life with a prosthetic hook that has come to embody his new reality. Just before he sets off for Mexico, Linda agrees to accompany him on this perilous journey fraught with moral dilemmas.
Rane's motives remain concealed as he sends Linda into a dodgy Mexican cantina to locate "Fat Ed." Unbeknownst to her, she is entrapped in the web of the vile Lopez, who has sinister plans for her. Fortunately, Rane arrives just in time to rescue her, extracting crucial information from the unscrupulous lowlife. Despite her apprehension about Rane's intentions, Linda finds herself unwillingly ensnared in a world of violence and treachery.
Their travels through dusty towns and winding roads expose them to deadly foes determined to reclaim their lives. In a rundown bar, Rane confronts Automatic Slim, igniting a vicious battle that leads to Slim being injured by Rane’s hook hand during a narrow escape.
Meanwhile, Cliff begins to unravel Rane's scheme upon discovering the modified firearm. Hustling through his police connections, he tracks Rane's vehicle to Lopez’s hideout, leading to an explosive confrontation. The two men engage in a chaotic struggle that barrels through an abandoned house and into a stockyard, culminating in a fierce gunfight where Cliff must eliminate Lopez and his associates.
As the body count rises, Linda and Rane share a deepening bond, molded in the flames of shared experiences and mutual comprehension. One evening in a seedy motel in El Paso, they connect authentically, with Linda unearthing her tomboy past while Rane reminisces about the simple joys lost to the ravages of war. However, during a vulnerable moment, Linda implores Rane to abandon his quest for vengeance. Ultimately, she leaves him with a wad of cash, but her resolve to reach out to the authorities evaporates, influenced by the intimacy they have forged together.
Rane continues his covert surveillance of the murderous gang, culminating his efforts at a disreputable brothel in Juárez. Meeting with Vohden at their stronghold in El Paso, Rane arrives to find him estranged from his family, shielding himself emotionally. Briefing Vohden unreservedly, Rane then leads them back to the brothel where Vohden secures the company of a courtesan. As they ascend to their scheduled rendezvous, Rane infiltrates via the fire escape, timing his entry perfectly. He incites a fierce gun battle that results in the deaths of T-Bird, Melio, and several other infamous criminals, finally culminating in a climactic confrontation between Rane and Automatic Slim. In a chilling display, Rane eliminates Slim and callously unleashes a barrage of bullets into his lifeless body. Wounded and battered, Rane and Vohden emerge from the brothel, their bond unbreakable and forged in the fire of their tumultuous and bloody exploits.
