Yep. I've put a lid on chapter 4. Or, at least a draft of chapter four. It's not quite as "done" as I'd wanted it to be: for example, the second half of the chapter is still littered with square brackets advising me to check a reference here, or add some more analysis there, and the conclusion is, frankly, lame. But the honest-to-god truth is that I simply couldn't look at this thing anymore. I had gotten to the point where I was simply moving around the deck chairs on the Titanic, so to speak.
So anyway, even as we speak, the thing is printing out. I'm going to post this, then label a file folder "Chapter 4 Draft", and put it in my desk drawer, never to be looked at again until I've got drafts at this level of all the other chapters, too. By then, I should have some perspective.
Oh, and by the way: in this last iteration, the chapter lost some 550 words, so the word count went backwards for a while. Not bad, though: I expected this chapter to be about 13,000 words, and it ended up at 15,500 -- for better or for worse.