I LOVE this book. THE RAVEN TOWER reminds me of my favorite Bujold, the Five Gods series, and it actually has a lot in common with Bujold's Sharing Knife series too, but it's undeniably an Ann Leckie book. By which I mean, it masterfully manipulates form in order to delicately craft plot. It's the kind of writing that any writer, reading it, has to admire even if your own style is quite different.
Maybe you're not a writer and aren't swayed by talk of how the use of second person--an entire novel, in second person!--creates a sense of obsessive omniscience and also furious constraint, or rather of pulling furiously against constraint, as a quality of the prose itself.
Here's what I would say if I were to try to sell a non-writer friend on reading this book:
It has: gender crookedry, a priesthood of old women, blood sacrifice, all of world history, gods from between the stars and the depths of time, backstabbing and also many other types of stabbing, flawed heroes, clever brave girls, a forest that eats babies, emotional entanglement, plots and schemes, revenge and pestilence and a victory in the end that will leave you feeling as free as--well, as a very free thing. As free as camping alone in Joshua Tree and looking straight up into the dark dark night at a sea of stars that are so close you could reach out and touch them.
I love this book. Read it immediately.