A beautiful June day in the Yorkshire Dales, and a group of children are spending the last of their half-term freedom swimming in the river near Hindswell Woods.

But the idyll is shattered by their discovery of a man's body, hanging from a tree. DI Annie Cabott soon discovers he is Mark Hardcastle, the well-liked and successful 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 back from the idyllic weekend he had planned with his new girlfriend. Banks soon finds himself plunged into a shadow-world where nothing is what it seems, where secrets and deceit are the norm, and where murder is seen as the solution to a problem. The deeper he digs the more he discovers that the monster he has awakened will extend its deadly reach to his friends and family. Nobody is safe.