The first three Campion novels, "The Crime at Black Dudley", "Mystery Mile" and "Look to the Lady", were all written by what Allingham referred to as the "plum pudding" method, focused less on methods of murder or the formal strictures of the whodunit and more on mixing possibilities together. As the series progresses, however, Campion comes to work more closely with the police and MI6 counter-intelligence. He also falls in love, gets married and has a child, and as time goes by he grows in wisdom and matures emotionally.