When Janet and Oliver Gowdie move to a quaint mountain town, their daughter Casey becomes part of a horrific chain of events revealing that their neighbors are anything but what they seem. Soon an unsettling old woman named Agnes Early fixates on Janet and Oliver’s other daughter–2-year-old Isobel. It becomes clear that it’s impossible to know who to trust… or who is even still human…

Casey’s uncanny behavior and obsessive interest in her younger sister raises suspicion in Oliver as he spirals into further paranoia that his step-daughter and their neighbors aren’t who or what they claim to be. Oliver’s fear becomes so overwhelming, in fact, that Janet’s family must fight to keep themselves sane, as the outside world becomes increasingly monstrous…