In sixteenth century England, fear of witchcraft abounds. But witches are not the only source of evil, as Dr William Gilbert will discover ... When Dr William Gilbert is caught in an Essex snowstorm, his life is saved by a strange, wolf-like dog. Taken in by the family that owns the animal, he is nursed back to health in an eerie, isolated building with a terrible history, where the cries of a child echo through the corridors at night. Having recovered, William is pleased to leave the Old Priory, but equally grateful to the husband, wife and daughter that saved him. So, when the women are accused of witchcraft and seem certain to be burned, he feels duty-bound to help them, despite the dire warnings of his father. To the people of sixteenth-century Essex, witches are everywhere and to associate with them is destruction. Nevertheless, William is driven to seek justice for his saviours, and as he delves into the case, discovers there is evil at play, of a type far worse than any invented tale of witchcraft. But can he prove that before the next victim dies and the innocent burn?