All right, everybody—it's really happening! I got the manuscript back from my editor. On the 345 pages, there are 4,101 edits (holy moly). Some are minor—a comma here, an adjective there—and some edits need fully rewritten paragraphs or sections.
The good news is one of my editor's comments in the email she sent: "There were several times actually that I found myself wrapped up in reading and had to go back because I realized I hadn't done my editing along the way!" (Aw shucks, I bet you say that to ALL the authors!)
It looks like I'll be heads-down in this next stage for the next few days. Send snacks.