In the year 2055, a catastrophic event occurs when an artificial intelligence (AI) radios a nuclear warhead that obliterates Los Angeles, California. This revelation leads the Western nations to engage in an all-out war against AI, in a desperate attempt to avert mankind's extinction. However, they face resistance from inhabitants of New Asia—which includes Southeast Asia, Japan, Taiwan, Bangladesh, Bhutan, Nepal, and parts of India—who have chosen to embrace AI technology rather than fight against it. To counter the growing threat, military forces develop the USS NOMAD (North American Orbital Mobile Aerospace Defense), a sophisticated space station designed for executing devastating orbital strikes.
Within this fraught atmosphere, U.S. Army sergeant Joshua Taylor, portrayed by John David Washington, operates undercover alongside his pregnant wife Maya Fey, played by Gemma Chan. The military suspects Maya is the daughter of Nirmata, the enigmatic figure behind the advancements in AI. When their home is raided, revealing Joshua's covert status, Maya manages to escape but is subsequently struck by a military strike from NOMAD.
Fast forward five years, and we find Taylor participating in cleanup efforts in Los Angeles. Here, he is contacted by General Andrews and Colonel Howell, who enlist him for a mission to annihilate "Alpha O," a new weapon designed by Nirmata that poses a grave threat to NOMAD's existence and the war's trajectory. To entice him, they display a video suggesting Maya is alive, leading Joshua to believe they could be reunited if he joins the operation.
Moving into New Asia, Taylor, now separated from his team, infiltrates a compound that supposedly houses the weapon, only to uncover an advanced robotic “simulant” resembling a young girl. He names her Alphie and discovers she possesses extraordinary abilities to control technology. Despite Allison Janney’s Colonel Howell's instructions to eliminate Alphie, Taylor defies her orders. Together, they search for Drew, Taylor's former commanding officer.
In their journey, Drew, portrayed by Sturgill Simpson, assesses Alphie and informs Taylor that she could develop into the most formidable weapon on Earth as her capabilities surge. The dangerous encounter escalates as New Asian police invade Drew's apartment and tragically kill his simulant girlfriend Kami, played by Veronica Ngo, just as Howell and McBride, portrayed by Marc Menchaca, close in. With Drew's assistance, Taylor discovers a signal from Maya but is ambushed, resulting in Drew sustaining fatal injuries while shielding him. Before perishing, Drew reveals that the catastrophic raid five years prior happened due to erroneous intelligence suggesting Maya was Nirmata.
When Taylor and Alphie are captured by the New Asian forces led by Harun, a simulant warrior and Taylor's old ally, he learns that the nuclear detonation was triggered due to human error, a fact the U.S. government wrongfully pinned on AI, who merely desire peaceful coexistence. After a daring escape, Taylor saves Alphie and meditates on their next move as a fierce assault led by Howell approaches. Alphie's intervention using her unique abilities leaves her gravely injured at the hands of McBride.
In a heart-wrenching moment, Taylor discovers that Maya has been in a comatose state since the strike on their home, cared for by simulant monks. This revelation leads to the stunning truth that Alphie is an embodiment of their lost unborn daughter, her scanning conducted in utero before the calamity. Overwhelmed, Taylor decides to take Maya off life support. As Howell and her forces confront him, Harun intervenes, stating that the eradication of NOMAD is essential for peace.
As the conflict escalates, Taylor and Alphie are taken into custody by U.S. troops in Los Angeles, where he finds himself forced to eliminate Alphie using an electromagnetic pulse weapon. However, General Andrews soon uncovers the elaborate deception and manages to aid their escape before Alphie meets her fate. As they make their way to a lunar shuttle at the Los Angeles Interplanetary Air and Space Port, Alphie morphs the spacecraft to land on NOMAD while Andrews initiates a global assault against the remaining AI strongholds.
In a dramatic climax, Taylor plants a timed bomb aboard NOMAD while Alphie disables its power supply. Yet, just as he attempts to escape via a pod, Andrews activates a monstrous robot that bars his path, prompting Taylor to eject himself with Alphie on board. The ensuing explosion of NOMAD halts the military offensive and sends shockwaves across the world. With profound emotion, Taylor embraces a simulant molded in Maya's likeness, activated by Alphie using a data chip containing memories Howell extracted from Maya's brain before her death. In their final moments, as NOMAD erupts in flames, both Taylor and Maya perish, while Alphie returns to Earth, observing the populace celebrating NOMAD's downfall and hailing her as Nirmata.
