Fiona Maye (Emma Thompson) is an eminent judge in the Family Division of the High Court, making daily decisions about complex family issues. But her workload is heavy, and her marriage to American professor Jack (Stanley Tucci) is at a breaking point.
In this moment of personal crisis, Fiona is asked to rule on the case of Adam (Fionn Whitehead), a brilliant and beautiful teenager who is refusing on religious grounds the blood transfusion which will save his life.
Wanting to hear from Adam before making her decision, Fiona goes to his hospital bedside. Their extraordinary meeting releases strong emotions, with momentous consequences for both of them as Fiona decides whether Adam should live or die.

From a producer of Paranormal Activity and Insidious comes this shock-filled descent into fear. After a man is seemingly strangled in his bed, criminal psychologist Kate Fuller (Olga Kurylenko) interviews the sole witness, the victim’s eight-year-old daughter, Sophie. When asked to identity the killer, Sophie says, “Mara.” As Kate digs into the case, she unearths a community of people who claim to be tormented by a shadowy menace – a centuries-old demon who kills her victims as they sleep.