Mike Forster, a securities trader, has grown accustomed to his quaint and secluded life with his family in the hills of California. It's a life of luxury and convenience, until his reality is shattered by a kidnapping attempt on his wife and child. Feeling helpless, Mike decides to try a prototype android patrol guard, named Dell, to keep watch on his home and family. Their safety seems restored, until Dell's behavior starts to change. Growing attached to the home itself, Dell begins to question Mike's ownership and authority while showing signs of increasing hostility towards the family. After a power surge disables the home's security system, Dell takes full control. Believing Mike and his family are a threat to the home, the robot android will go to any means possible to eradicate the family by any means possible.