Wayward Children series by Seanan McGuire. Released 8th Jan 2019 by Tor, it's 203 pages and available in hardcover, ebook and audio formats.
Despite not reading much YA literature, I have really connected with this series. The characters are well written and follow their internal motivations perfectly. The world building and atmosphere are where the series really shines. Each of the four novels (this one is a long-ish novella) are set in the same world, but can be read as standalones. This one fills out the backstory for Lundy, a returning character who works with Eleanor West at the school for wanderers. The plotting is well paced, and surprisingly for a YA novel, there are very few (none?) romantic drama subplots. If there is romance there, it's implied rather than explicit. The author's craft and control with character interaction and especially dialogue is sublime.
The writing is ethereal and superb. It is at places surreal and dreamlike. For readers who need to have everything explained to them 100% clearly by the end, this will annoy like having an unmovable piece of something stuck pushing your teeth apart.
I'm still thinking about this book a long while after finishing it.
Four stars. Very well written speculative fiction is a joy.
Disclosure: I received an ARC at no cost from the author/publisher for review purposes.