In the year 1980, a group of assassins including Danny Bryce (Jason Statham), Hunter (Robert De Niro), Davies (Dominic Purcell), and Meier (Aden Young) embark on a mission in Mexico to eliminate a target. Tragically, during the operation, Danny ends up killing the man right in front of his young child. The aftermath leaves Danny wounded and deeply affected, leading him to retire and return home to Australia.
Fast forward a year, and Danny receives a call to Oman, where Hunter is being held hostage. There, he meets the Agent (Adewale Akinnuoye-Agbaje), who informs him that Hunter took on a $6 million job but failed to execute it. The serious stakes reveal that if Danny doesn't complete Hunter's task, Hunter will face execution.
Danny soon learns that he is tasked with killing three former SAS agents—Steven Harris (Lachy Hulme), Steven Cregg, and Simon McCann—who were responsible for the deaths of Sheikh Amr's three eldest sons during the Dhofar Rebellion. To fulfill this mission, he must record their confessions and stage their deaths to appear accidental, all before the terminally ill Sheikh passes away. This would pave the way for the Sheikh's fourth son, Bakhait (Firass Dirani), to reclaim control over his father's domain. To help in this dangerous mission, Danny reunites with his assassin friends, Davies and Meier, who agree to aid him for a cut of the promised payment.
As they infiltrate the house of their initial target, Steven Harris, Davies investigates the local scene for intel on former SAS members. However, their movements draw the attention of the Feathermen, a clandestine group of former operatives. The head enforcer, Spike Logan (Clive Owen), is dispatched to look into their activities, leading to a dangerous cat-and-mouse game.
During the confession videotaping of Harris, an unexpected visitor disrupts their plan. What was meant to appear as an accident turns into a lethal struggle when Meier unfortunately kills Harris out of desperation. Back in London, Davies learns about their next target, Steven Cregg, who is training for a night march in harsh winter conditions. By feigning car trouble outside the base, Davies helps Danny infiltrate it. Danny proceeds to drug Cregg’s coffee to induce chaos, leading to his death from hypothermia while confessing on tape. Just when Danny thinks he's home free, he narrowly escapes Logan's watchful eye.
As the hunt progresses, Danny realizes that Logan is tailing them. The Agent contacts the British government, revealing a larger conspiracy at play, hinting that they might be manipulating the Sheikh for his oil. They assure Danny that the government will handle Logan, but tensions rise when Danny discovers that their plot involves powerful interests at stake.
For their final target, Simon McCann, Danny and his team employ a remote-controlled truck to orchestrate his demise. But the plan goes awry, leading to unexpected casualties including the tragic death of Meier orchestrated by their inexperienced teammate, Jake (Michael Dorman). Heartbroken by their losses, Danny and Davies reluctantly agree to disband.
Upon returning to Oman, Danny presents the Sheikh with the last confession tape, ultimately securing Hunter's freedom. However, Danny soon learns of one last task involving the notorious Ranulph Fiennes—an author planning to release a tell-all book about his SAS experiences. Danny informs Anne (Yvonne Strahovski), a childhood friend, to escape to France with Hunter for safety, while he prepares to complete his dangerous mission.
As Danny navigates through deception and betrayal, he opts to merely wound Fiennes, leaving a trail of evidence that misleads everyone into thinking he is dead. A confrontation ensues with Logan, which culminates in interference from the British government, revealing their own motives—a power struggle over the Sheikh's valuable oil reserves.
As alliances crumble and betrayals unfold, Danny ultimately faces Logan one last time. Exhibiting a sense of closure, Danny relinquishes the money that was due to him and Hunter, deciding instead to let Logan keep it for his own future, concluding that he has chosen to leave behind this dangerous life. With an intention to start anew, Danny reunites with Anne in France, looking forward to leaving his past behind.
