Arguably the sequel to The Drowning City, although they’re in different settings with almost entirely different sets of characters, so knowledge of the first isn’t necessary to read the second. I’d been pretty meh about The Drowning City, though with no more specific criticism than “It didn’t grab me.” I probably wouldn’t have bothered with The Bone Palace except then I heard it had a transgender protagonist, and there are precious few of those in fantasy, so I was motivated to give it a try.
Verdict: better than the first one, but sharing most of the same flaws. Namely in characterization — nobody really made me care. I’m still not quite sure what the secret to writing compelling characters is, but I suspect it has to do with CARING about things — about a cause, about a person, whatever, it doesn’t matter. As long as the character is passionate about SOMETHING, some of it will spill over onto the reader as well, but in Downum’s books, all the passion is told rather than shown. And while it’s very unusual (and therefore interesting) to have a book populated entirely by female protagonists, I would have liked more about Kiril and Nikos; seeing as how love-for-those-dudes was a primary motivation for some of the female protagonists, it wouldn’t hurt to show us why those dudes were worth fighting for.
On the plus side, her world-building is rather good; very atmospheric, she has some cool ideas for magic, and she’s clearly put a lot of thought into some of the commonly-overlooked aspects of creating a fantasy world. (Mind, certain aspects of her city of Erisin are also uncannily reminiscent of Monette’s Melusine, and I would be very surprised if it turned out that Downum hadn’t read Monette before.)
TL;DR version: I dunno, find something else, prolly. I’d recommend Santa Olivia, not because it’s anything similar, but because it’s the best thing I’ve read recently.