In his famous essay, "The Simple Art of Murder," Raymond Chandler insisted that in a crime narrative the hero "is everything." In his private notebooks, published since as "Twelve Notes on the Mystery Story," he was equally resolute: "The hero of a mystery story is the detective. Everything hangs on his personality. If he hasn't one, you have very little." In Philip Marlowe, Chandler created one of modern literature's most famous and enduring characters, a hero so vivid and real that even his off-stage life became the subject of interest.

Chandler, obliging, fleshed it out when asked to do so. In a 1951 letter to D. J. Ibberson, entitled "The Facts of Philip Marlowe's Life" which was published in Selected Letters of Raymond Chandler, we learn that the detective is about forty, has no living relatives, attended college for a couple of years, worked as an investigator for an...