Devoted to their devastated mother, siblings Aidan and Mia resent Grace, the younger woman their newly separated father plans to marry. They flatly reject Grace’s attempts to bond, and they dig up dirt on her tragic past—but soon they find themselves trapped with her, snowed in in a remote holiday village after their dad heads back to the city for work. Just as relations begin to thaw, strange and frightening events threaten to unearth psychological demons from Grace’s strictly religious childhood.