The gates between the human world and the world of demons suddenly swung wide open - and a stream of ghosts and wraiths, zombies, werewolves and dozens more creatures of Darkness poured into modern cities. However, life goes on... only paranormal crimes have been added to human crimes, and the eternal rivals of the police - private detectives - have been replaced by master exorcists. Felix Castor was once considered the best of such exorcists in England, but now he has retired and refuses to even hear about his former work. But money is never too much... and expelling a weak demon who has taken up residence in an ancient church archive building is a piece of cake for an experienced master. Simple? Too simple. And free cheese, as you know, only comes in a mousetrap. And a “too easy” case turns out to be the most difficult and dangerous in Castor’s entire career...