In this captivating film, we follow the lives of four centuries-old immortal assassins—Charlize Theron as Andy, Matthias Schoenaerts as Booker, Marwan Kenzari as Joe, and Luca Marinelli as Nicky—who are determined to remain hidden from the world. Their existence is marked by constant danger and the need for utmost secrecy, which is vividly illustrated when Andy discreetly erases a photo featuring her to prevent their identities from being exposed.
The story begins with an intense scene where the four are ambushed and shot during a covert operation in South Sudan, highlighting both their vulnerabilities and resilience. Despite being riddled with bullets, their supernatural healing abilities enable them to recover swiftly and eliminate the threat, revealing their secret power to the audience. Their mission, assigned by Copley (Chiwetel Ejiofor), an ex-CIA operative, involves tracking down a violent militia terrorizing local communities. As they navigate this perilous assignment, they realize they may have been set up, and the scene ends with them injured and questioning their trust in Copley and their own allies.
The narrative then shifts to scenes in Afghanistan where Nile Freeman (Kiki Layne), leading a team of U.S. Marines, encounters a brutal terrorist leader. During a mission to rescue captives, Nile is gravely wounded but, much to everyone's surprise, heals completely while in a medic tent, hinting at her own immortality. This awakens the four assassins to the possibility of finding someone like them—a revelation that deeply impacts their understanding of their own existence.
In London, Copley attends a presentation of technological advancements from his employer, Merrick, who aims to use his company's innovations to save lives. Copley shows Merrick footage of the assassins’ recent mission, impressing him but demanding concrete proof of their supernatural abilities for further experiments, which hints at Merrick's increasingly dangerous intentions.
The story explores Nile’s growing sense of alienation after her near-death experience, leading her to be transferred for more tests. Andy quickly intervenes, rescuing Nile from the authorities and later revealing her own doubts about their purpose and mortality. As Nile begins to suspect her newfound abilities, she and Andy meet in conflict, with Nile grasping that she truly cannot die, a realization that profoundly affects her.
Further flashbacks reveal the tragic tale of Quynh (van Veronica Ngo), Andy’s former partner and the first immortal she encountered. Quynh was captured and sealed in an iron coffin to drown for centuries, a haunting image that underscores the everlasting pain of their curse. Nile's empathetic connection to Quynh’s suffering becomes a poignant subplot, emphasizing the enduring toll of their immortality.
The protagonists face devastating setbacks when Merrick’s mercenaries—employing increasingly vicious tactics—attack their hideout, capturing some team members and wounding others. During confrontations, Joe (Marwan Kenzari) and Nicky are subjected to brutal interrogations, revealing the extent to which Merrick seeks to destroy or control them. Meanwhile, Booker’s betrayal is uncovered when he turns against the team, shooting Andy, believing Merrick’s claim that ending their immortality could bring peace.
As Andy’s wounds heal more slowly, the remaining team members unite for one final assault on Merrick’s facility. During this climactic showdown, Copley joins forces with Nile, revealing his own conflicted role and helping to free the captives. Andy fights Merrick directly, ultimately killing him with her axe before Nile pushes him out of a window, ending his reign of terror. Their victory is hard-won, with wounds and scars serving as a reminder of what they've endured.
In the aftermath, Nile is considered “killed in action,” a cover story to protect her from Merrick’s lingering shadow. The team resolves to remain in hiding, with Copley continuing to assist them. Booker, having betrayed his friends, is sent into a century-long exile in Paris, where he is unexpectedly visited by Quynh, reopening old wounds and hinting at the ongoing pain and unresolved battles that define their eternal lives.
Throughout the film, themes of loyalty, betrayal, resilience, and the quest for peace in a life without death intertwine, creating a richly textured story that examines what it truly means to live forever.