The film begins with a mysterious scene overlooking the ocean, where a crew, led by an enigmatic woman portrayed by [Uma Thurman], retrieves an ancient iron maiden from the water. Upon breaking it open, they discover the immortal [Veronica Ngo] inside, fighting to breathe after centuries of confinement. This opening sequence sets the stage for a story steeped in long-hidden secrets and ancient powers.
In a different part of the world, in Croatia, the legendary team known as The Old Guard—consisting of Charlize Theron as Andy, Chiwetel Ejiofor as Copley, Kiki Layne as Nile, Marwan Kenzari as Joe, and Luca Marinelli as Nicky—are on a dangerous mission targeting a notorious arms dealer named Konrad, played by [Slavko Sobin]. During this mission, Andy struggles with the unsettling loss of her immortality, a condition that has defined her existence for centuries. The team orchestrates a daring attack, with Joe and Nicky creating a distraction on the road, battling Konrad’s henchmen while Andy, Copley, and Nile infiltrate his compound.
Inside the mansion, they confronting guards before ultimately forcing Konrad to his death off a balcony, an act witnessed by the others. After the successful operation, the team retreats to their hidden sanctuary. Copley reveals that Konrad was merely a pawn, with the real buyer being a mysterious woman spotted in CCTV footage—who, Nile recognizes from her dreams as someone she’s seen in visions, entering a library and killing an unknown man. This revelation deepens the mystery surrounding their enemies.
Meanwhile, in Paris, a disillusioned and drunken [Matthias Schoenaerts] as Booker, has been living in self-imposed exile after losing his own immortality. One night, he is shocked to find [Yvette Etiévant] as Louise, the boss of a local café, standing in his apartment. She seeks his help to locate Andy, blaming her for Quynh’s long imprisonment underwater. Quynh, played by [Veronica Ngo], then appears unexpectedly, asking Booker how she can find Andy, expressing feelings of betrayal and anger towards her for her perceived abandonment, as she was trapped for five centuries.
Nile joins Joe and Nicky in the search for Booker, while Andy and Copley seek out another immortal, Tuah, who resides in a vast library. Tuah reveals that the mysterious woman is named Discord, who was actually the first immortal, not Andy. Both Quynh and Discord were present at the time of Quynh’s execution, with Discord holding a different view on mortal affairs. While Tuah remains uncertain about Discord's motives, Andy confides in him that she has lost her immortality.
The team reunites after locating Booker, who provides a crucial message from Quynh. Nile then sets out to find Quynh, and when they finally meet, a tense confrontation ensues as Quynh accuses Andy of abandonment. The situation escalates with a brief fight before Discord herself emerges, revealing her desire to reclaim her lost immortality. She claims to be the first immortal and suggests that Nile, whose powers seem linked to her wounds, might hold the key to restoring her eternal life.
Later, Booker confesses to Nile that by injuring him during a sparring session, her wounds caused him to lose his immortality—though he keeps this secret from everyone else. The team uncovers that Discord and Quynh are planning to set off nuclear bombs at a facility to kill millions, a deadly trap designed to lure them into a final confrontation. Despite knowing the danger, they rush to intervene.
In a fierce battle at the nuclear plant, the immortals face Discord’s henchmen. Booker makes a heroic sacrifice, enduring a deadly attack that restores Andy’s immortality when he takes a blow meant for her. He fights bravely, taking down numerous enemies before succumbing to a permanent death. Meanwhile, Nile and Quynh battle fiercely; Nile manages to injure Quynh, stripping her of her immortality, but also gets wounded by Discord in the process.
Andy fights Discord on the rooftop of the facility, where Discord reveals her plan: to take the powers of Joe, Nicky, and Tuah to regain her immortality. Despite her formidable strength, Andy is outmatched, and Discord escapes with her captives. In the aftermath, Andy returns to her library, where she is met by Quynh once more, and the two reconcile. Together, they resolve to team up and pursue Discord, determined to prevent her from gaining her destructive, immortal ambitions.
Throughout this gripping tale of eternal life, ancient rivals, and moral dilemmas, the story explores themes of loss, redemption, and the true cost of immortality. Each character’s journey reveals their vulnerabilities and strengths, leading to a climactic, emotional resolution that leaves the fate of the immortals open to future stories.
