Oliver is a middle-aged lecturer in Comparative Religion, with a passion for trivia, crosswords, and anagrams, and a very strange taste in jokes. Having been fired from the University of the Rhondda Valley, and with no family ties, he decides to set off on a quest to find "Aristotle", a setter of crosswords. He soon teams up with Woman Police Constable Diane Priest, who has just been suspended from the police force because she has been asking too many questions about a local murder that seems to implicate the Chief Constable. Pursued by Baxter ("the man with no name"), Oliver and Diane visit Shrewsbury, North Yorkshire, Durham, Hadrian's Wall, and Kirkleven in the Scottish highlands on their journey to find "Aristotle" in the Orkney Isles. Along the way, they uncover a major scandal centred around a property company.