I have very much enjoyed the Steerswoman series from Rosemary Kirstein. It's a really well-imagined, interesting world, and the over-arching story of the whole series is being told at just the right pace to keep you intrigued. The story of this book specifically, though, is a little slow and it doesn't really come together until towards the end. But the last part of the book is tense and the revelations intriguing.
What I particularly like about this series is that each book is its own story. You definitely benefit from having read the previous books, but each separate novel comes to a satisfying conclusion, rather than spending the last 20% setting up the next volume.
I'll post a spoiler alert comment with some more details about the plot.