Kale's punishment for his violent outburst at school is to be put under house arrest, with an electronic bracelet tracking his movements. His mother, Julie, is strict with the rules, limiting his internet and phone usage and keeping a close eye on him. With nothing to do, Kale starts to spy on his neighbors, becoming particularly obsessed with the Turner family who just moved in across the street.
Kale becomes convinced that the father, Robert Turner, is a killer when he sees strange behavior from him and notices that several people who have entered the Turner's house haven't come out. Kale enlists his friends, Ronnie and Ashley, to help him investigate, and they start to break the rules to get a closer look at what's going on.
Their investigation leads them to discover that Turner is actually a serial killer who has been preying on young women. They try to get the attention of the police and save the latest victim, Turner's daughter, but their efforts are thwarted by Turner himself.
In the end, Kale manages to expose Turner as a killer, with the help of the police and a recording they made of Turner confessing to his crimes. While the experience has been traumatic for Kale and his friends, they have also formed a closer bond and learned valuable lessons about trust and survival.