In the aftermath of a miscarriage, prospective parents Kate (Farmiga) and John (Sarsgaard) find their lives turned upside down; their marriage is falling apart, and the demons of Kate's past begin manifesting themselves in a series of horrifying nightmares. Deciding that the best means of achieving some semblance of normalcy is to simply adopt, the dejected couple visits a local orphanage. There, they are both drawn to a nine-year-old girl named Esther. But Esther isn't as sweet as first impressions suggest, and almost immediately after welcoming the young child into their home, Kate and John suspect that something is terribly wrong with their adoptive daughter.