Morse and Lewis hunt a violent rapist who has escaped from prison. They find themselves drawn into an under-world of satanists, and some of them seem more respectable than others.

A man suspected of being a multiple murderer is killed in prison while on remand awaiting trial, leaving the disappearance of a fifth woman unsolved. 
In the missing woman's effects was a postcard of a pre-Raphaelite painting, the background of which was painted in some woods near Oxford. Morse is assigned to a new murder investigation when what appears to be her body is found in the woods.