A beautiful June day in the Yorkshire Dales, and a group of children swimming in the river near Hindswell Woods discover a man's body, hanging from a tree. DI Annie Cabott soon discovers he is Mark Hardcastle, the set designer for the Eastvale Theatre's current production of Othello. Everything points to suicide, and Annie is mystified. Why would such a man want to take his own life? Then Annie's investigation leads to another shattering discovery, and DCI Alan Banks is called in. Banks soon finds himself plunged into a shadow-world where nothing is what it seems. The deeper he digs the more he discovers that the monster he has awakened will extend its deadly reach to his friends and family.