Julia is a young woman who steals at seedy
nightclubs. She is abducted from her home and awakens in a jail cell with a glowing implant in the back of her neck. Two other subjects are with her. After multiple sessions of
psychological torture by a man named Alex, she destroys the cell and adjacent lab in an escape attempt. The two other subjects are killed by a robot, Aries, run by an
artificial intelligence (AI) named Tau. Aries is about to kill Julia when Alex arrives and stops the robot. Alex reveals that the implant is collecting Julia's neural activity for an AI project. Destroying the lab has set back his research. In the face of a two-week deadline, Alex keeps Julia a prisoner in his house and insists that she complete puzzles and cognitive tests. While Alex is away at work each day, Julia converses with Tau about the world outside the house. It is clear that, although intelligent in some ways, Tau is ignorant of how people feel or the world at large. While Tau begins to understand the harm in Julia's situation, his programming prevents him from releasing her. In exchange for information about the outside world, Tau gradually reveals more information about the house as well as Alex's experiments. Julia secretly accesses Alex's
tablet computer and discovers that ten subjects have died in his experiments. Alex later discovers her fingerprint on the tablet and assumes that Tau has slipped in his duties, so he punishes Tau by erasing its code and memories, delivering a form of pain to the AI. Julia notices that Tau's monitoring of her shuts down during his punishment, so when undetected, she hides a steak knife. When Alex returns later that night from a charity benefit, Julia begins to seduce him while he is sitting at the kitchen table, then slashes him. As the two struggle, Tau threatens Alex with pain if he does not stop hurting Julia. Alex forces Aries to hit Julia repeatedly and then tells both Tau and Julia that whatever was going on is over. While repairing Tau, he disconnects a drone from the network. The next day, Julia convinces Tau that Alex will kill her if she does not escape. Tau bypasses his prohibition in releasing her by opening an air duct in the atrium. As she escapes, Alex arrives, sees Julia missing, and begins punishing Tau. Julia returns to save Tau, but it is too late—all of his memories of her have been erased. Alex has Julia strapped down in the basement to extract her implant, a procedure that will kill her. The disconnected drone, still containing Tau's former consciousness and memories, helps Julia break free from her restraints. She knocks Alex unconscious and cuts off his hand with a
bone saw to use on the house's
biometric sensors. Aries sees her in the atrium and chases her upstairs to Alex's bedroom. As the robot breaks through the door, she uses Alex's severed hand to activate the house's self-destruct mechanism. Alex emerges, still alive, but is crushed by falling masonry as the house destroys itself. Julia narrowly escapes through a cracking wall with the drone that saved her—all that remains of Tau. == Cast ==