A stressed and jealous middle-aged banker is married to a young actress, Susanna, and they have a six-year-old daughter, Ella. Theo is a hated man because he was accused of cheating on his first wife, but was found not guilty. Out of the blue, they decide to go on a holiday to a large, isolated house in the Welsh countryside to work through their relationship problems. But soon they have nightmares and Theo believes that something evil is lurking in the house.