Raymond Chandler is the master, the guy who pretty much created the pattern for most of the fictional, tough-guy detectives that would follow Chandler's own Philip Marlowe. Written in 1953 (while his wife was dying of a terminal illness), The Long Goodbye is my favorite of all the Philip Marlowe novels because of how much it reveals about Marlowe's character and core beliefs. Marlowe is a cynic with a good heart, a man attracted to the down and out characters he so often finds on the streets of Los Angeles. He still believes that he can help them, even though more times than not, he fails to do so.
One of those whom Marlowe tries to help is a hopeless drunk by the name of Terry Lennox. Marlowe and Lennox meet late one night when a woman angrily drives away and leaves the appallingly drunk Lennox standing alongside Marlowe outside a restaurant. After Marlowe takes the man home with him so that he can safely sleep off his drunk, the two men become friends of a sort. Things get interesting a few months later when Lennox comes to Marlowe looking for a quick ride to the Tijuana airport. Marlowe, hoping to avoid incriminating himself, refuses to listen to the reason for the sudden trip but decides to drive his friend to Mexico despite his suspicions that Lennox is in trouble. Upon his return to Los Angeles, Marlowe learns two things: Lennox's wife was murdered just before the man left town, and the cops know that Marlowe helped him flee the city.
Chandler, never one to shy away from using coincidence to move his story along, uses the device effectively several times in The Long Goodbye to keep Marlowe involved in Lennox's problems long after their late night drive to Tijuana. For instance, when a New York publisher asks Marlowe to help find missing writer Roger Wade, another out-of-control drunk, the detective (only after the man's wife personally asks for his help) reluctantly agrees to take the job. As it turns out, there are connections - several of them - between Terry Lennox and the Wades, and what Marlowe learns about those connections keeps him hanging around the Wades a whole lot longer than he ever intended to.
Probably because of what he and his wife were going through at the time he was writing The Long Goodbye, the novel has a more serious tone than what Marlowe fans had come to expect from Chandler. Marlowe is presented here as a cynic trying to get by, a hard man with a soft side who values friendship but has few friends because he understands that he lives in an every-man-for-himself world where he is all too often the odd man out. This aspect of Marlowe's character not only makes Chandler's writing a little different from most of the detective fiction of his day, it is one of the chief influences on the writers who followed him.