Founders trilogy by Robert Jackson Bennett. Released 21st April 2020 by Random House on their Del Rey imprint, it's 512 pages and available in hardcover, audio, and ebook formats.
This is a phenomenally well written book. Despite the fact that I hadn't read the first book, this book hooked me. The review has waited a few months because I fell in love with the writing, but found the plot so hard to follow that I needed to go back and read the first book. (It doesn't work well at all as a standalone and they're both doorstop chonky books (512+ pages each)). Getting to the point of being able to write a review was a bit of a commitment. I'm glad I took the time.
I found this installment much less of a rollicking fantasy magical engineering marvel (but not "steampunk-y in the slightest) and more of an exploration of created family, loyalty, pragmatism, good-vs-evil and general epic high fantasy. The magic system is subtle and believable. The author explores the ramifications of the system logically and well. There's an appealing f/f romance subplot which doesn't detract from the main adventure, but might not be *enough* romance for readers who prefer a little plot with their romance.
In some ways, Bennett's writing (and this trilogy) remind me most of Yoon Ha Lee (Machineries of Empire) and Seth Dickinson (The Masquerade) which is sort of weird because they're both really SF writers and this is definitely fantasy. The point is, he's a top shelf writer of speculative fiction and this book is *really* good, maybe one of the best SF/F offerings I've read this year, just don't try to read it as a standalone. I've intentionally avoided offering a precis of the plotline for 2 reasons: first, every other reviewer does just that and second, it's too complex to sum up in a couple of paragraphs.
Four and a half stars.
Disclosure: I received an ARC at no cost from the author/publisher for review purposes.