When an American family (Mackenzie Davis, Scoot McNairy and Alix West Lefler) is invited to spend the weekend at the idyllic country estate of a charming British family (James McAvoy, Aisling Franciosi and Dan Hough) they befriended on vacation, what begins as a dream holiday soon warps into a snarled psychological nightmare. As the weekend progresses, they realize that a strange side lies within the family who invited them: the untrammeled hospitality of the charismatic, alpha-male estate owner masks an unspeakable darkness.