When the body of a young woman is found on the Lady Chapel altar in Hereford Cathedral, it appears that serial killer The Sacristan has set the grandest stage yet for his unholy tableaux, and the newspapers waste no time in stoking up public fear and fury. But there are slight differences between this case and those of The Sacristan so, fearing that a copycat killer has taken up a grisly challenge, Lambert and Hook set about discovering all they can about the dead girl.

And there is much to discover, with many theories and many suspects: there is the well-known Member of Parliament who was paying for her sexual favours; the passionate young actor who had begged her to give up her destructive lifestyle to marry him; and her abusive step-father, who has recreated himself as the charismatic leader of a money-grabbing cult. And there is still the matter of The Sacristan.

Lambert and Hook have little time to solve one of the most puzzling cases of their career, before the media drown the police force in a wave of hysteria. . .

Lambert and Hook must find the crocodile amongst these tearful suspects In the midst of a heatwave in Gloucestershire, unseen hands slide the body of a young woman quietly into the waters of one of England's great rivers under cover of darkness. It is some days before the corpse is discovered, and the police have first to identify the victim as Clare Mills and then try to build up a picture of her puzzling lifestyle.