Yeah, so, turns out I was right about 1) Curse rewrites and 2) Halloween gumming up the writing works. I shipped out the last costume yesterday afternoon, and this morning I got up and wrote a couple pages on a new chapter of the third Jacob Tracy book. Which is now titled Confounded Immortals, if you're playing along at home.
I'm pretty sure I know what's going to happen next. And that's such a good feeling.