The stressed and jealous middle-aged banker Theo is married with the young actress Susanna and they have a six-year-old daughter, Ella. Theo is a hated man since he was accused of drowning his first wife, but he was considered not guilty by the justice. Out of the blue, they decide to travel on vacation to a huge, isolated house in the Welsh countryside to resolve the problems in their relationship. But soon they have nightmares and Theo believes something evil is hidden in the house.