MI5 Officers Brian Courteous and Archie Twentyman are sent to the village of Hardon at the request of the Archbishop of Canterbury to investigate rumours of widespread promiscuity and the mystery of why the village has had four vicars in the last twelve months, one of which has totally disappeared. They soon discover that the Parochial Church Council (PCC) turn out to be a gang of eccentric and sinister characters and the duo's mission proves to be a little more dangerous than they first imagined.