Oliver is an involuntarily retired professor with a yen for Beethoven, Jazz and puzzles of all kinds. Diane Priest is a WPC (Woman Police Constable) whose suspicions about a superior officer get her booted from the force. They team up on a journey that Oliver thinks will lead to love, since Diane's statement "Diane, not Priest" is an anagram for "predestination." She thinks he's a loony, but is intrigued by his promise to tell her "the very funny thing I know about sex."