Behind its impenetrable walls, the residential Close of Melchester Cathedral is troubled by a growing sense of uneasiness among its populace. Towards whom, or what, it would have been difficult to say -- until slanderous messages against the head verger, Appledown, started appearing everywhere: in anonymous letters addressed to various members of the community and even in a banner unfurled after morning prayers in the presence of the staff and students of the choir school.

Following so closely the tragic, accidental fall of Canon Whyte from the roof of the Cathedral, these events fill the Dean with foreboding. So he decides to invite his young nephew, Bobby Pollock, to come down for a visit. He has heard that Bobby joined the Metropolitan Police Force after graduation and is now attached to Scotland Yard. Sergeant Pollock arrives to conduct a minor investigation during his short holiday in the country but instead finds himself in scandal and murder of much more serious proportions.