This was Raymond Chandler's first novel, from 1939, penned after a few years writing short stories for pulp mags like Black Mask and Dime Detective. I think I first read it back in the early 1970s, maybe once or twice since. And (of course) I watched both the movies one with Bogie and the other with Mitchum in the role of private eye Philip Marlowe. When I noticed that used paperbacks of this "annotated" version were pretty cheap at Amazon, I bit. Always looking for new insights.
Chandler's text (footnoted) is printed on the book's left-side pages. Footnotes themselves (written by scholars Owen Hill, Pamela Jackson, and Anthony Dean Rizzuto) are on the right-side pages. This makes them easy to follow.
The classic opening has Marlowe "calling on four million dollars": the frail oil magnate General Sternwood at his palatial estate in Beverly Hills. (One of those footnotes points out that $4 million in 1939 would be about $70 million today. A decent sum in any case.) Marlowe is tasked with investigating how Sternwood's younger daughter, Carmen, wound up being blackmailed by a shady bookseller named Geiger. And (by the way) Sternwood's older daughter, Vivian, has a missing husband that the General took a liking to. But Marlowe isn't asked to investigate that. Not directly, anyway.
Well, Phil is off to the dark underbelly of sunny Los Angeles. (Where it seems to be raining a lot.) Geiger turns out to be a sordid character indeed, but before Marlowe can confront him, Geiger winds up on the floor of his house with a couple of slugs in him. Witnessing all that was a drugged and naked Carmen. And there's a camera. Empty. And then other bodies start piling up.
So much for the plot, how much do the annotations add to the reader experience? It's a mixed bag. Some are trivial. (Did you know that a "croupier" is the guy running the roulette wheel? Well, maybe not everyone does.) Some are overly literary, looking for symbolism and psychosexual indications. The anecdote about Chandler being asked by movie screenwriter Leigh Brackett who committed one of the murders, and replying that he didn't know for sure—that's here. Some others are pretty interesting. For example, I never noticed that (spoiler, sorry) "Pretty much everything that did happen [in the novel] would have happened anyway without Marlowe." Well, I can think of one thing, but I get the annotator's point: Marlowe observes, he's less of an active participant. Not for lack of trying though.