Five episode British miniseries. Oliver, a professor of comparative religion, 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. Based on the book by Creator/AlanPlater.

!!Contains examples of:

* ChekhovsGun: Oliver finds a [[spoiler:king from a chess set in Aristotle's abandoned house]] which at the end, allows [[spoiler:Oliver to know that he has found Aristotle's house in the Orkneys]].
* CrosswordPuzzle
* BlackHelicopter
* CorruptCorporateExecutive and AristocratsAreEvil: Baron Kite.
* EnigmaticMinion: The mysterious Baxter, who shows up from time to time to make vaguely menacing conversation and warn Oliver and Diane off their investigation. [[spoiler: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]].
* TheEveryman: Diane's nice but ordinary son Michael.
* DaddysGirl: Diane's father calls her every day, no matter where she is.
* FacelessGoons: A man in a balaclava who turns out [[spoiler:to be Diane's son, who has been working for a security firm involved in the coverup]].
* PlayfulHacker: Michael's friend who helps dig out the evidence of the villains' wrongdoing.
* PublicSecretMessage: 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.
* RunningGag: 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.)
* SeekingTheMissingFindingTheDead: When Oliver and Diane reach the town in the Orkneys that Aristotle moved to and ask for directions, they're directed to the graveyard.