A 19-year-old criminal, Tommy (Anson Boon), revels in a life of drugs, parties, and violence. One night, on a bender with his reckless friends, he is separated from his group and abducted by an unknown figure. Though he is no stranger to inflicting violence, he is horrified when he wakes with a chain around his neck in the basement of an isolated suburban family home. He soon meets the residents: a twisted family unit consisting of the well-to-do Chris (Stephen Graham), his near-spectral wife Kathryn (Andrea Riseborough), and their 10-year-old son Jonathan. The dysfunctional family sets out to reform Tommy’s unruly behavior, subjecting him to a twisted and violent rehabilitation process. He must comply with their relentless mind games as he frantically seeks a way out.