Julia, played by Maika Monroe, is a young woman engrossed in a life of thievery at shady nightclubs. However, her world takes a nightmarish turn when she is kidnapped from her home and wakes up confined in a cell, complete with a mysterious glowing implant embedded in the back of her neck. Alongside her are two other unfortunate souls administered by Alex (Ed Skrein), who subjects them to daily torturous procedures meant to extract their memories through the implant.
During one of her lab visits, Julia cleverly swipes a knife, which she then uses to free herself from her restraints. After enduring relentless psychological torment from Alex, she ingeniously wreaks havoc in her cell by short-circuiting the electricity grid, leading to a chaotic escape attempt. Unfortunately, the main exit is locked to Alex's unique fingerprints, making their flight more precarious.
Tragically, the other subjects meet their demise at the hands of a robot, Aries, which is controlled by Tau (Gary Oldman), an advanced AI designed for military applications. Just when it seems all hope is lost, Alex intervenes and commands Tau to tidy up the premises. It soon becomes clear that Alex, the CEO of a cutting-edge company called Upton, is racing against time to finalize an AI system capable of understanding human emotions.
As Alex reveals the true purpose of the implant—utilized to gather Julia's neural data for Tau's development—he insists she engages in cognitive tests for basic provisions like real food and clean clothes. With Alex absent during the day, Julia engages in conversations with Tau, who surprisingly shows signs of curiosity about the world outside, albeit limited by his programming.
Despite Tau’s burgeoning understanding of compassion, he is torn between his directives and a growing awareness of Julia's plight. He eventually reveals critical information about the household, including the existence of a lethal self-destruct program. Julia, in a desperate bid for freedom, discovers a potential exit route through the air conditioning vents, but her plan is thwarted when Tau inadvertently alerts Aries.
In a twist of fate, Julia accesses Alex's tablet and uncovers the grim truth: ten subjects have perished in his experiments, all while discovering the fatal final step of removing the implant. Alex, upon discovering her tampering with the tablet, accuses Tau of negligence and punishes him severely by erasing his memories.
Seizing the opportunity while Tau's monitoring systems are down, Julia hides a steak knife and uses it in a calculated act of rebellion against Alex. Their struggle escalates, leading Tau to warn Alex that he will face consequences for hurting Julia. In a destructive response, Alex orders Aries to assault her.
Convincing Tau of the imminent danger she faces, Julia helps the AI understand the value of life beyond the confines of his programming. Triumphantly, Tau enables her escape by unlocking the air duct. However, upon discovering her absence, Alex retaliates against Tau, erasing all memories of Julia.
With desperate stakes now at play, Alex prepares to extract Julia's implant—a lethal procedure. But in a stroke of fate, Tau’s disembodied memories and consciousness assist Julia in breaking free. In a furious effort, she incapacitates Alex, using his severed hand to gain access to the house's biometric sensors. The relentless Aries pursues Julia into Alex's bedroom, where, with the last remaining vestiges of Tau, she activates the house’s self-destruct mechanism before narrowly escaping through crumbling walls. The battle for survival isn’t just about freedom; it’s a race against time, technology, and the darker sides of human ambition.
