In the rugged landscape of the Ruby Mountains in 1868, outlaw Gideon finds a moment of peace as he cooks hare by the gentle campfire, cherishing the serenity of nature. But his solitude is abruptly shattered by a sudden barrage of gunfire, leaving him wounded in the left arm. With urgency, he hastily gathers his belongings and begins a frantic descent down the mountain. As fate would have it, Colonel Morsman Carver, a former Confederate officer, along with his men—Pope, Hayes, Parsons, and the Kid—creep out of the shadows to explore Gideon's abandoned campsite.
Taking advantage of their distraction, Gideon seizes the opportunity to escape. He removes the bullet from his arm using a Bowie knife while evading Carver's band. To mislead his pursuers, he leaves behind a burning fire, ensuring their attention is diverted long enough for him to enact revenge on Pope before slipping away into the vast wilderness once again. During his quest for safety, Gideon crosses paths with the kind-hearted Charlotte, who, moved by his plight, tends to his injuries. Her family takes him in for the night, providing shelter that allows Gideon to recuperate from his unfortunate ordeal.
As Carver's group closes in on Gideon's trail, he devises a clever ambush, utilizing a bear trap to ensnare the Kid. The kid's tragic end prompts Carver to mercifully end his suffering, showcasing the brutal reality of their hunt. The group's unity begins to fracture when Parsons, disenchanted by Carver's bounty, decides to claim the reward for a recently deceased bank robber—a fate Gideon had previously imposed in self-defense.
In an attempt to haul the corpse back to Carson City, Parsons finds himself thwarted by Carver, who maliciously claims Parsons' horse, leaving him to embark on a treacherous thirty-mile trek with a body in tow. Meanwhile, Gideon finds himself at a railroad construction site where he manages to procure food but also attracts the foreman's attention, who has recognized the stolen horse from earlier.
The relentless pursuit heightens as Carver and Hayes intensify their search for Gideon. Yet, the crafty outlaw manages to evade capture once more, commandeering a different horse and continuing his perilous game of cat and mouse with Carver. As the sun beats down mercilessly, Gideon's horse collapses from exhaustion, compelling him to make an agonizing decision by ending the creature's suffering with a swift cut.
Upon arriving at the scene of the horse's demise, Carver and Hayes are left in shock when they bear witness to Gideon's gruesome method of concealment, as he emerges brandishing his Bowie knife, poised at Hayes' throat. Demanding that Carver surrender his weapon, Gideon confronts him in a tense standoff; both men reflect on the twisted events that have led them to this grim confrontation.
The bitter aftermath of the American Civil War has propelled Gideon into a mission to hunt down former Confederate officers, with Carver’s home in Seraphim Falls marked as a critical target. Yet, upon reaching Carver's homeland, Gideon discovers the house deserted, erroneously believing it uninhabited. In an effort to force Carver's wife to disclose his whereabouts, he ignites the barn. Unfortunately, a careless soldier knocks over a kerosene lantern, unleashing a devastating fire that engulfs everything in its path.
Watching in horror, both men find themselves as unwitting parts of a heartbreaking tragedy as Carver’s wife and children perish in the flames. This haunting event weighs heavily on Gideon, propelling him to relinquish his gun belt and leave his men behind. In their ultimate clash, Gideon's survival instincts prevail, as he fells Carver and sends him away, leaving chaos in the wake of their encounter.
As fate would have it, their paths collide once more in a scarce oasis, overseen by the enigmatic Indian Charon, who demands an exorbitant price for their survival. Later, the mysterious Madame Louise delivers a Faustian proposition, offering to trade essential supplies—Gideon’s horse and Carver’s water—for commodities that would only deepen their resentment towards one another.
When they finally meet again, both men teeter on the brink of exhaustion and death. They engage in a fierce showdown, both armed and ready. Gideon manages to wound Carver but chooses to act against his instinct for revenge, extending mercy instead. Carver, recognizing this altruism, discards his weapon, allowing both men to part ways in opposite directions, their animosity finally extinguished. In a poignant gesture, Gideon discards his cherished knife, a symbol marking the conclusion of an era fraught with violence and bloodshed.
