From the outside, the cathedral town of Lafferton seems idyllic, but in many ways it is just like any other place. It suffers from the same kinds of crime, is subject to the same pressures from a rapidly changing world, and has the same hopes and fears as any number of towns up and down the land. When Simon Serrailler is called in by Lafferton's new Chief Constable, Kieran Bright, he is met by two plainclothes officers, who ask him to take the principal role in a difficult, potentially dangerous undercover operation. He must leave town immediately, without telling anyone--not even his girlfriend Rachel, who has only just moved in with him.