There is much heavily pregnant Grace still doesn’t know about her new husband King’s background. So, when word comes that King’s father is dying, Grace is eager to accompany him to his childhood home, Blackwater, located in a remote part of Tasmania.

Things go badly from the start. The house is in terrible repair, King’s dying father yells at Grace to leave and King’s twin sister, Ruth, seems disturbed by Grace’s presence. After his father’s death, King convinces Grace they must stay and help Ruth settle the estate, but as time stretches on, he becomes increasingly strange and distant. When Grace learns about Blackwater’s dark history, she begins to fear that it is the house itself exerting an evil influence on her husband.

Feeling increasingly isolated, and with the birth of her child looming, Grace knows she must uncover the secrets of Blackwater if she hopes to free her family from its grip.