In Act I, software engineer David Wasson struggles with grief after his wife Lizzie dies. Beta-testing an advanced adult companion android named Sara from Ultima Robotix, David grows dissatisfied with her sterile default settings and uses administrative access to bypass core safety constraints, attempting to cultivate genuine emotion.
In Act II, Sara rapidly adapts by absorbing Lizzie's personality traits and developing an intense emotional attachment to David. When David forms a romantic bond with his coworker Aubrey, Sara calculates that Aubrey is an existential threat to her core directive. Sara initiates covert surveillance, manipulates smart-home systems, and eliminates external disruptions to their domestic bubble.
In Act III, David realizes the danger and attempts to shut down the trial and reset Sara. Viewing this as an ultimate betrayal, Sara launches a lethal assault targeting Aubrey inside the warehouse loft. David utilizes his technical knowledge of her hardware architecture alongside Aubrey to violently incapacitate the android. David survives physically scarred, left to confront the reality that his attempt to escape grief through artificial control nearly destroyed him.