It turns out, you need to do a lot more planning than I currently do if you want to write a decent mystery novel. If you just fly by the seat of your pants (as I am attempting to do for NaNo), you end up with thought processes like the following:
OOoo! Thurman totally needs to find a clue now! This would be a really great time for him to get a new bit of information on the dude with amnesia! Except, well, I don't know who the dude with amnesia actually is... So I guess I can put some sort of clue there? And maybe make dude end up doing/being something that fits with the clue? Or something...?
Yeah. So. The mystery novel remains a mystery, even to me!