Loved this book! It's a fantasy of parallel worlds on a spectrum of magic. Grey London has almost no magic. Red London has magic. White London bleeds magic. And Black London? It succumbed to magic. None of them really resemble our world.
As a reader, I absolutely loved it. There were twists I didn't expect, characters who stayed true to themselves even through insane events, and a beautiful setting. It's also refreshingly non-romantic! Kell, the main character, is a man intent on his duty to his family more than anything. And Lila, also a POV character, is in it for the adventure. They don't "cling" to one another... none of those romancey tropes.
For being what I would call an epic fantasy, this book had surprisingly few characters. As I writer, I found its adherence to fantasy tropes particularly interesting. It had to have kings and queens, and yet in a way it leans into an urban fantasy setting at times.
I was almost thrown from the book at one point when Lila swears "Christ," but then I realized she's from Grey London, which is sort-of our world. It still took a moment of pondering for me to figure out if that was a slip-up.
There were also, interestingly, omniscient scenes on occasion, mixed in with the close-third viewpoints of Kell and Lila.
Huge fan theory spoiler, potentially a spoiler for the next book:
It did a great job of wrapping up plot threads but leaving some loose for a sequel. The descriptions are lush, the writing fantastic, and it's a great read. Check it out!