The important thing about noir is the ride, not the mystery. Seriously, if you're reading (or watching) The Big Sleep in order to find out Whodunnit, you're making a mistake (and you will go insane). You can bet (and you'd be right) that the mystery Pynchon's noir set in Nixon-era Los Angeles with a pot-smoking hippie detective is not going to make a lick of sense. Some of the journey doesn't make sense either, but at least it's a fun ride. Also interesting that the PI's office is in the South Bay, so a lot of the local geography in the book is familiar territory. Apparently, Pynchon lived in Manhattan Beach for a few years around that same time, so it all definitely has the ring of authenticity.