1993. After the death of her parents, a Montana girl of twelve years old has to go live with her aunt, a very conservative woman. Cameron Post (Chloë Grace Moretz) is a perfect high school girl who, after being caught with a partner in the backseat of a car the night of the dance, is quickly sent to a therapy center where she deals with teenagers " struggling with the attraction to the same sex. " On the premises, Cameron is subject to an outlandish discipline that includes dubious methods and Christian rock songs. However, this environment also provides the young woman with a community in which to feel identified. For the first time, the protagonist connects with her peers and is able to find her place among the marginalized.