I think I had a big breakthrough yesterday. I got one major scene rewritten, and now I'm up to the part where I realized while writing it that it was a major turning point scene, so what's there is essentially a placeholder until I can figure out exactly what will happen. That will require more research and a trip to the library today. However, I've passed the approximate halfway point. Yay! This part I'm working on is probably going to be the hard part of the entire book. The rest should actually be pretty easy -- unless I come up with something else that I didn't anticipate.
One weird thing that had a lot to do with spurring me on to productivity: I realized I was really missing a character. I've been wrestling with this one part of the book for weeks, and the character who is possibly my favorite isn't in this section. I found myself missing him and looking forward to getting back to him, and to do that, I have to finish this section so we can return to his part of the story. In the finished book, he won't be away for too long. It's just that it's taken me so long to deal with this one part that it's been ages since I've written him.
Meanwhile, a character I wasn't expecting turned up and came to life, and now I need to think of more things for him to do because he's a lot of fun. He should also be useful because he has an interesting skill set, and that skill set may actually bring him into some kind of interaction with another character you'd never imagine with this kind of person.
Oooh, I'm being all hinty and vague, aren't I? But I don't like to talk in specifics about works in progress and especially about works that aren't contracted. This one is still on submission. I hope someone buys it because I think it's a lot of fun.