When Nathan Appleby (Colin Morgan), a pioneering psychologist, inherits Shepzoy House in a beautiful but isolated Somerset valley, he decides to make a new life for himself and his adored wife, Charlotte (Charlotte Spencer). But soon the idyll is compromised by strange and disturbing occurrences that all seem to inexplicably swirl around the increasingly troubled Nathan. Is he being haunted? Why? And by whom? The answers will shatter every belief this man has ever held and threaten everything and everyone he has ever loved.