A man staggers out of his cottage into the streets of Oxfordshire, shattering an otherwise peaceful evening with the terrible sight of his body shaking and heaving, eyes wild with horror. Many of the villagers believe the Devil himself has entered Joseph Makepeace, the latest victim of a “great fog” that darkens the skies over England like a Biblical plague. When Joseph’s son and daughter are found murdered–heads bashed in by a shovel–the town’s worst suspicions are confirmed: Evil is abroad, and needs to be banished.