Ollie and Caro Harcourt are moving house with their twelve-year-old daughter Jade. Ollie is desperate to leave the city. Caro is less sure. Then they view Cold Hill House, a dilapidated rural mansion, and fall instantly in love. It's expensive, but with its space, seclusion, and huge grounds, it seems like a brilliant idea.

That is, until they arrive.

It soon becomes apparent that they are not alone. A spectral woman appears on screens and walks the corridors, vanishing before she can be challenged. Strange occurrences become ever more common. Then Caro starts seeing faces, always looking out of the same upstairs window.

The room behind it could hold the key to the disturbing secret behind the house's mysterious past. Except for the fact that the room doesn't seem to exist . . .