Critics of the British detective novel have generally agreed that it is a conservative genre. The detective functions as the guardian of the status quo: he brings to justice criminals who have threatened middle-class stability by threatening the foundation of that stability—money. Not surprisingly, the genre itself is a product of the nineteenth century, for only this century saw the triumph of a class into which an outsider could buy his way—as he could not into the aristocracy—if only he could get his hands on capital. The getting of capital, therefore, motivates most criminals to murder in detective fiction, and the detective is worshiped by the middle classes who understand that their wealth and position will eventually be safe in his hands.

Given the conservatism of the genre, one can further predict that stereotypes of character will seldom be violated. Thus, upon opening an [Margery...