A former banker, his actress wife, and their spirited daughter book a vacation at an isolated modern home in the Welsh countryside where nothing is quite as it seems.
Theo Conroy is a writer struggling with a past trauma. He takes his wife Susanna and their daughter Ella to a vacation house in Wales, which starts to plague them with haunting dreams.
An evil spirit named Stetler haunts the house and has haunted it for generations. He tries to take Ella into his realm but promises Theo she can come out if he does what he must. Theo admits to Susanna that he deliberately let his first wife drown in the bathtub when he could have saved her. Ella is free but Theo’s soul remains in the house.
The film starts with a little girl, Ella (Avery Essex), walking through the halls of her house, muttering some swears to herself. A ghostly man named Stetler appears to grab her. This turns out to be a nightmare that Ella’s father, Theo Conroy (Kevin Bacon), is having.
Theo is married to an actress named Susanna (Amanda Seyfried). When he tries to visit her on set, he is denied access by one of the assistants. Theo is also unhappy that one of the scenes Susanna just filmed was very sexual. It is implied that people have an aversion to Theo due to a past incident that he is getting over
The Conroys go to stay at an old-fashioned vacation home in Wales. After exploring the place, the family seems to love it. That night, as Ella is making shadow puppets, she sees what looks like the shadow of a man appear on the wall. Theo and Susanna try to get intimate, but after Theo goes to turn down the thermostat, he finds Susanna apparently asleep already. He lightly nudges her and she wakes up startled, claiming to have had a bad dream.
Theo writes in his journal as a way to cope with past trauma. Susanna and Ella go walking in the woods, when Ella asks her mom why people seem to hate her dad. Susanna explains that Theo’s first wife drowned in the bathtub, and people suspected that Theo killed her, although Susanna does her best to defend Theo. Later, Theo finds out that Susanna told Ella and admonishes her for it since he was waiting for the right time to talk to her about it. This leads to an argument, but Theo apologizes to her.
Theo goes into town for some groceries. The shopkeeper (Colin Blumenau) asks Theo if he is staying up in that house and makes a reference to Stetler and all the houses that have been up on that hill. As Theo leaves, another random woman asks him about Stetler.
Later that night, Theo goes to listen to his self-help tapes when he can’t sleep. He wanders through the house and finds what appears to be a hidden stairway in the bookshelf. He follows it downstairs and comes across what appears to be Ella’s body. He knows it’s a dream and he tries to wake himself up by slashing his wrists, and then his throat. Surely enough, Theo wakes up unharmed.
The next day, the family prepares to leave since they are not having a good time. Theo watches Susanna and Ella play outside. He tries to text her something, but as she looks at her phone, he finds the same phone on the kitchen counter. He then goes to look at his journal and finds things that he never wrote inside it. He then goes outside to give Susanna the other phone and assumes she is using another phone to talk to another guy named Max that is apparently her ex. This leads to another argument that ends with Susanna leaving the house by herself without Theo and Ella.
Theo and Ella start to check out the weird things about the house, like how when he drops water, it splits into two nearly symmetrical halves, as well as how the interior of one room is larger than the exterior. Later, the two of them appear to be experiencing visions in the dream world, but Theo manages to get back to Ella. He tries calling for a cab and gets the shopkeeper to answer him, telling him that no taxis are in that area and something about the devil collecting souls from that house.
Theo and Ella prepare to leave by walking away from the house. Theo can see a figure standing by the window observing them. Eventually, they walk right back to the house somehow. Theo convinces Ella to stay there for the night, but as they sleep, Theo enters the dream world again and sees his and Susanna’s past selves as they first came to the house and admired it. He then finds that Ella is trapped and he cannot find her. He confronts Stetler, who takes Theo’s form to taunt him. He says he will return Ella on the condition that Theo does what he must. Ella is returned to him, and he embraces her.
Susanna returns, and Theo puts Ella in the car. He finally comes clean to Susanna about what happened with his first wife. He didn’t directly kill her, but he saw her lose consciousness and simply did not choose to save her, letting her die as he watched. Susanna is horrified. We then see that Theo’s soul is now trapped inside the house.
The last we see is the the halls of the house as the shopkeeper’s voice says that some people don’t leave the house. A listing for it then becomes available on a website.