When Guy Fletcher protests at a feeble joke he overhears in his grotty local pub, he finds himself headbutted and struck by an idea in quick succession. Is it possible to trace a joke all the way back to its original source? Guy's meandering trail leads him to a humourless Hungarian dentist, a hyperactive troupe of Boy Scouts, a group of giggling grave-diggers and half a dozen undercover detectives. And there are some pretty odd things happening along the way. Guy is sure he's being followed by a sinister Englishman, Irishman and Scotsman. He has an unfortunate accident on a banana skin. And there's a fly in his soup. Guy is on the verge of discovering something very unpleasant. Making jokes is no laughing matter...