Oliver, a professor of comparative religion with a penchant for word games, is fired from his job and decides to take a road trip to the home of his favorite crossword compiler, who uses the pseudonym Aristotle. When he finds the house abandoned, he alerts the police and eventually secures the assistance of a police investigator, Diane Priest. She discovers that Aristotle is now living in the Orkneys, as well as suggestions of high level corruption.
Oliver proposes marriage to Priest because when she is telling him how to address her, she says, "Diane, not Priest" which is an anagram for "predestination." She refuses, but they travel together to the Orkneys, he investigating the disappearance of Aristotle, and she investigating the coverup she begins to reveal. Gradually, connections appear linking the two incidents into one vast conspiracy, and things begin to get out of hand.
Contains examples of:
- Aristocrats Are Evil: Baron Kite.
- Black Helicopter: One attacks the car Oliver and Diane are traveling in.
- Chekhov's Gun: Oliver finds a king from a chess set in Aristotle's abandoned house which at the end, allows Oliver to know that he has found Aristotle's house in the Orkneys.
- Corrupt Corporate Executive: Baron Kite.
- Crossword Puzzle
- Enigmatic Minion: The mysterious Baxter, who shows up from time to time to make vaguely menacing conversation and warn Oliver and Diane off their investigation. It turns out that he's Kite's chief of security. And then it turns out that he's Aristotle's son, that he infiltrated Kite's organization in an attempt to bring Kite down, and that in between warning Oliver and Diane off he's also been feeding them the clues that enabled them to put everything togther.
- The Everyman: Diane's nice but ordinary son Michael.
- Daddy's Girl: Diane's father calls her every day, no matter where she is.
- Faceless Goons: A man in a balaclava who turns out to be Diane's son, who has been working for a security firm involved in the coverup.
- Good All Along: Baxter is Aristotle's son. He infiltrated Kite's organization in an attempt to bring Kite down, and in between warning Oliver and Diane off he's also been feeding them the clues that enabled them to put everything togther.
- No Full Name Given: The rest of Oliver's name is never revealed. It's not even made explicit whether "Oliver" is his given name or his surname.
- Playful Hacker: Michael's friend who helps dig out the evidence of the villains' wrongdoing.
- Public Secret Message: Aristotle's crosswords are still appearing in the newspaper, and at one point Oliver realises that the one he's just done contains a hidden message indicating who's behind the coverup.
- Running Gag: Oliver's habit of telling everyone he meets that he knows a strange and amusing fact about sex, in the hope that someday somebody will ask him what it is. (Diane eventually does.)
- Seeking the Missing, Finding the Dead: When Oliver and Diane reach the town in the Orkneys that Aristotle moved to and ask for directions, they're directed to the graveyard.