Mike Regan (Pierce Brosnan) is a self-made aviation tycoon (he owns a private jet leasing business which he wants to take public in a IPO) who lives in a state-of-the-art smart house full of modern technologies with his wife Rose (Anna Friel), and 17-year-old daughter Kaitlyn (Stefanie Scott). Mike's company is developing an app called "Omni Jet" (allowing customers to book a private jet just as they would book an Uber) which will increase business while they raise much-needed capital with a stock offer. The Securities and Exchange Commission (SEC) needs to approve it, though.At the company, he meets a 28-year-old I.T. consultant, Ed Porter (James Frecheville), whom he calls to fix his home's Wi-Fi signal which his daughter complains is slow. Porter also upgrades Mike's car's GPS and claims that he also worked at the NSA and had joined the military exercise in Kandahar. Mike invites Porter to the family's barbecue.Porter meets Kaitlyn and starts a relationship with her through social media, but Mike fires him after Kaitlyn invites him in the house, cutting his promising career at the company. Devastated, Porter begins to remotely access Mike's private data, including his house, as he covertly monitors them through the security cameras and devices all over the house. He even spies and records Kaitlyn, unknown to her, masturbating in the shower room.Porter sends fake emails to Mike's clients and the SEC, threatening the company's survival. He also takes full control of the house's technology, which leaves the family terrified, and using a spoof email sends Rose fake mammogram results saying that she tested positive for breast cancer. Rose is devastated, but the truth is her test results were negative according to her attending physician. After Mike realizes that Porter had done it, he attacks Porter and threatens to kill him if he does not stay away from his family.Porter then uploads the video of Kaitlyn masturbating, immediately catching the attention of her schoolmates, leaving Kaitlyn embarrassed. She blames her father for the technology installed in the house. Angered, Mike drives on his way to Porter but he is also being monitored by Porter, who mockingly phones him through the car navigation system and sends the video of his daughter masturbating. Porter then remotely activates the car's brake system, hitting a nearby stalled truck and destroying the car.Mike requests help from I.T. expert Henrik (James Frecheville). Henrik states that Mike must destroy all the smart technology in the house and delete all emails, bank accounts, and computer files. Henrik explains that Porter's real name is Richard Edward Portman and his father committed suicide when he was six years old. He also reveals that he never worked in the NSA, as he claimed, and the photo of him with the soldiers in Kandahar was fake. In order to take evidence from the apartment where Porter lives, Henrik makes a diversion by stealing a phone from a coffee shop waitress, whom Porter's obsessed about, and texts Porter to come to the coffee shop. While Porter's gone, Mike manages to take the thumb drives containing the evidence and escapes just as Porter realizes it is a diversion. Realizing that the masked man he saw in his apartment is Mike, he frames him for assault by injuring himself, but blaming it on Mike.After the police releases him, Mike goes back to his home to find Kaitlyn and Rose tied up and gagged by Porter, who holds the family at gunpoint. A struggle ensues; Porter shoots out a window and Mike punches Porter who hits his head, and lays dying as Mike holds the gun to his chest, but Rose begs Mike not to shoot. Sometime later, the employees applaud Mike and his family for successfully developing the app and their house is restored.