In South Africa, a convoy of Interpol agents, led by Lin, is tasked with transporting a prisoner named Keith. However, during a checkpoint stop, they are ambushed, resulting in a devastating loss as most agents are killed. Fortunately, Lin manages to escape with Keith in a tense and dangerous situation.
Meanwhile, Travis Conrad (played by Ethan Hawke), a hitman, is commemorating the one-year anniversary of the death of his loved ones by fishing with his father-in-law, Frank. After scattering ashes in the ocean, Travis leaves Frank asleep and heads to a bar to get cocaine. It's here that he is confronted by two thugs who inform him that Jim wants to meet him. Jim, offering an enticing $1 million per day, tasks Travis with cleaning up the mess following a botched assassination attempt involving Keith and Lin. Although he initially refuses, claiming it's time to leave that life behind, the promise of money sways him to accept the job.
Relocating to Hong Kong, Travis cunningly steals Lin's son’s cell phone to track her whereabouts. Upon meeting Lin at the airport, he uses his charm to seduce her and, the following morning, retrieves Keith's location from her phone. However, instead of fulfilling his contract, he refrains from killing her when she discovers his true intent and retaliates by killing him instead.
In a shocking twist, Travis is revived by his agency, Red Mountain, through an experimental procedure. After revealing Keith's location, he learns that his revival was merely a means to an end; the doctor plans to eliminate him once she gets the information. Escaping from his restraints with a scalpel, he manages to overpower a guard and learns that he now has only 24 hours to live. With the doctor as his hostage, he sets out on a mission to find Lin, warning her not to make him regret his decision to spare her life.
As Keith testifies against Red Mountain, he unveils the dark truth of their experiments on over 70 civilians in their quest for the resurrection procedure. Just as he bravely testifies, chaos erupts when Jim snipes guards from a distance, and Red Mountain storms the courthouse. In a desperate bid to escape, Lin and Keith flee when Travis arrives, now fully aware of Red Mountain's betrayal. Tragically, during their escape, Keith is killed, but he manages to secure the memory card containing crucial evidence against Red Mountain.
Travis entrusts this card to Lin, only to face another hurdle when Jim informs them that he has taken her son hostage in exchange for the card. Determined to rescue the boy, Travis gathers guns and explosives from a hidden stash. They then make their way to the village marked by the horrors inflicted upon civilians by Red Mountain, rallying the community to join them in their quest for vengeance.
Utilizing his knowledge of prisoner transport protocols, Travis devises a plan to ambush the convoy and successfully rescues Lin's son. He instructs her to take the testimony to the authorities while he prepares to face Red Mountain one last time, fully aware of his impending death.
Feigning to be a prisoner, he forces a surviving agent to drive him to the base where the enemy is headquartered. Once inside, he engages in a fierce battle, killing numerous guards as he crashes a vehicle into the building. In a climactic confrontation with Jim and Wetzler, the leader of Red Mountain, Travis faces a moral quandary; though seething with rage over the deaths of his family at Wetzler’s orders, he chooses mercy over vengeance and spares Jim.
In a shocking conclusion, Jim, feeling the weight of his betrayals, takes it upon himself to execute Wetzler but ends up gunned down by the police. As the dust settles, Travis succumbs to his injuries, envisioning a serene moment on a beach with his family. He calls out for his son, but the boy runs away, leaving Travis to hear a mysterious woman's voice beckoning him back to consciousness in the lab of his resurrection.
