Jay Cavendish (Kodi Smit-McPhee), a young man hailing from Scotland, embarks on a profound journey through the United States in pursuit of his beloved, Rose Ross (Caren Pistorius). His travels take him through dense woods, where he encounters a Native American camp, and witnesses a confrontation involving Union officers chasing a Native American. Just then, a bandit known as Silas Selleck (Michael Fassbender) appears, gun drawn at one of the officers. In a tense moment, Jay raises his weapon at Silas, but the bandit pulls the trigger first, shooting the officer. This encounter forges an unlikely bond between Jay and Silas as they decide to join forces.
Through a series of poignant flashbacks, we glimpse the tender moments shared between Jay and Rose back in Scotland, where they roll joyfully down a hill near the sea. Jay harbors deep feelings of love for Rose, who views him more as a brother, leaving him emotionally conflicted. As their journey continues, Jay and Silas traverse a picturesque field resonating with the sounds of a love song sung by three Congolese men. Jay expresses his fondness for the melody, sharing the notion that "love is universal like death."
However, lurking nearby are bounty hunters led by the threatening figure of Payne (Ben Mendelsohn). Their path crosses a shop where Silas spots a wanted poster featuring both Rose and her father, John (Rory McCann), with a hefty reward of $2,000 for their capture. Unbeknownst to Jay, who remains blissfully unaware, they barely avoid a deadly encounter when a Swedish couple, Johan and Maria (Karl Willetts and Brooke Williams), turn violent. Chaos ensues as Maria demands money from Silas and Jay, leading to Jay reluctantly defending himself and ultimately taking Maria's life, leaving behind two innocent children, Eva and Jan ([Evie and George Simon]), with only a handful of items.
In another haunting flashback, after Rose gently informs Jay that he feels more like a brother to her, she instructs him to hide under the bed. Hours pass before he hears a commotion as Jay's uncle Rupert (Alex MacQueen) arrives, dismissing everyone as peasants. In a shocking turn of events, Rupert physically confronts Rose, leading to John’s vengeful action that results in Rupert's death. This pivotal moment marks John and Rose's descent into outlaw life.
As Jay finally reaches America, he encounters a clergyman named Angus ([Tony Croft]), who shares his intentions of documenting the decline of the Aboriginal people while promoting Christianity. Seeking guidance, Jay finds himself alone the next morning with nothing but an egg containing a note simply stating "West." Breaking the egg, he lets its yolk fall away, a symbol of loss and potential.
Throughout their journey, as Jay and Silas grow closer, Silas begins to mentor Jay, even shaving his face using a knife, while Jay reveals his loneliness. When Payne surprises the duo at their campsite, it becomes clear that the bounty on John and Rose is a constant threat. Payne's manipulative tactics surface, as he tries to extract information from Silas but discovers nothing useful, because Silas left his mercenary past behind.
As they continue, Jay gradually realizes the truth about the danger surrounding Rose. Meanwhile, we see John and Rose living quietly in their secluded cabin, accompanied by their Native American ally, Kotori ([Kalani Queypo]). Their tranquility is shattered when an unknown visitor recognizes Rose, filling her with dread, though John reassures her of their anonymity.
The tension escalates as Silas imprisons Jay to prevent him from jeopardizing Rose's safety. However, as fate unfolds, a violent confrontation erupts between Silas's group and Payne’s gang, leading to a deadly exchange of gunfire. In the chaos, John is the first to fall, while Rose refuses to give up her fight for survival. In a dramatic turn, Silas intervenes, sustaining serious injuries in an effort to protect her. In a heart-wrenching moment, Jay rushes to Rose's side only to be shot by her in a tragic misunderstanding.
The aftermath is devastating; as Rose navigates the fallout of her actions, she is left to grapple with the reality of her own survival and loss. In a poignant conclusion, she takes Eva and Jan under her wing, while Silas remains a steadfast reminder of Jay's sacrifice and the love that transcended their tragic story.
