Oh, that Donald Westlake. He is such a card. In the third John Dortmunder escapade, Jimmy the Kid, Andy Kelp convinces the gang to kidnap the 12-year-old son of a wealthy Wall Street broker. The plan they will follow, to hilarious ends, is to be taken from a book, Child Heist, written by one Richard Stark. The joke here of course is that Richard Stark is the pseudonym that Westlake used for his series about the darker Parker, professional criminal.
It seems that Kelp read the book (which in real life does not exist) while he was whiling away some time in jail. Here, he thinks, are the perfect step-by-step snatch instructions and ransom negotiations.
Dortmunder and his crew refer to chapters in the Parker book - three or four of which are excerpted - and the reader then gets to enjoy how things don't go according to 'script.' It is all quite amusing and Mr. Westlake must have had much fun bringing the it-always-works-out Parker into the world of it-rarely-works-out Dortmunder.