Sara finds herself in a house she doesn't recognize, with a husband she doesn't remember and the creeping and foreboding shadows of a previous life closing in. Clues turn up, people, places and vague memories of friends and family, and as Sara tries to piece together the shreds of her missing past, she finds herself in a terrifying struggle for her very survival against the house itself, it's occupants and guests. As she uncovers the truth, Sara makes the horrific discovery that her true adversary is far more powerful and intimate than she can possibly understand, and the only way out of this hell, is to fall into it.