If you recall, I loved the previous books in this series. And I'm so glad that the third (and sadly last) book is as good as the previous two!
King is based mainly in Siphra. Akabe, the reluctant king, is desperate to build a temple to the Infinite. But it comes with a price - he must marry an Atean girl. And probably because he was upset that Ela rejected him (how could anyone not see that Ela and Kien were meant to be? Ok, fangirl moment over), he married her. The rest of the book deals with the Atean rebellion against the king (they have a queen that's Atean, why would they want the king to live?)
The queen is the 'new' character in the series, and I think she's actually really well-crafted. I could emphathize with her, although to be honest, I spent quite a lot of time wishing she wasn't so bull-headed. Still, she's young, vulnerable, and abandoned - bullheadness is probably one of the few ways she has to make sure she survives in an antagonist court.
What I liked about this series is that not all the Infinite's followers are admirable. They do a lot of, well I wouldn't say bad, but I would say "things you would disapprove off" like gossiping and such. It makes the world a lot more real to me.
For fans of Ela/Kien, I have really really good news - they get married in this book! (This takes place fairly early on, so this is not a spoiler). Of course, Ela is still struggling with her fear of an early death, because "a silver-haired prophet has failed". And Kien, when we last saw him, he was going to court in the Tracelands, and well, he lost. So the two of them have their own weaknesses, and it's beautiful to see how they mutually encourage each other.
This book has intrigue, romance and action (fight scenes, but nothing very gruesome). It's an awesome ending to a fantastic series!
Disclaimer: I got a free galley from the publisher via NetGalley in exchange for a free and honest review.