At book 13, she's in a rut. Certainly rutting, anyway. Page 1: she's worried that she's possibly pregnant, by one of the (counts) five regular partners. Much of the novel's about the need to increase that number, and much whining about it, plus avoiding auditions. It all takes place over a couple of days, during a run-up to a big night at the ballet where lots of scary people will be, and whether it's safe to go, and... in the final pages, Hamilton pulls the rug away. I don't mean a twist ending, I mean was that it?
For the last book, I complained that it was really just a prelude. So's this, only it's much thicker. But even then, that wasn't what I meant. This is a prelude in that it's obviously laying the stage for some events involving one of the off-screen Big Bads, but in this book, Hamilton sets up a situation and then betrays her protagonist's character at the end. Not good.
So it's annoying that I like the characters, because I really wish she'd get back to what it used to be about.