Clair lives in the leafy suburbs and has worked hard to create the perfect life for her husband and her two children. She has devoted herself to creating a safe world for her family; she feeds them well, helps out at school and volunteers on the parents and citizens committee. Clair knows from experience how harsh the world can be for children but in her mind she is able to hold any threats at bay - until a new family arrives in the area.
The first time she sees Chelsea she has her pegged as a spoilt only child who has the potential to change the ordered calm that Clair has woven. But she has no idea exactly what events are about to unfold.
A tragic accident that Clair interprets as something far more sinister proves to her that she was right to be strict with her children. But as she reacts to what is going on her children start to rebel. The tighter she reins them in, the less control she has. As she loses her grip on them and her ability to govern what happens to them she starts to lose her grasp on reality. Teetering on the edges of madness, Clair will do anything to protect her family and in so doing risks destroying all their lives.