Two children playing the game "Witch Hunter" near St. Bride's Church put a curse on a woman who enters the church and dies of an unknown cause. The case is so baffling, it's sure to be given to the Peculiar Crimes Unit, an unconventional group of investigators, led by Arthur Bryan and John May, who are assigned the really unusual murder cases.

Instead, PCU is given an even more perplexing assignment when their supervisor and longtime nemesis in the Home Office, Oskar Kasavian, asks for their help. His young wife is suffering behavioral problems and is becoming a security risk. Her personality dysfunction started six weeks ago, and now she's convinced her life is in danger. Even after she's confined to a clinic for mental evaluation, her paranoia does not dissipate. When a news photographer assigned to cover her at public appearances is brutally murdered, the case takes on new dimensions.

Bryant and May are doing everything they can solve their boss' dilemma, but dealing with so many politicians soon puts them and the PCU team in eminent danger. And the complexity of the case makes traditional investigative approaches ineffective. Discovering an unusual link between the two cases has Bryant and May at odds with their supervisors as the truth finally reveals itself in a most bizarre way.

THE INVISIBLE CODE by Christopher Fowler is another great addition to this clever and enthralling series. Bryant, May and their PCU colleagues are smart and resourceful as they deal with some of the most inexplicable and tricky murder cases in London.