Right, cards on the table: I read Graceling when it first came out and loved it. I grabbed Fire when that came out and ab-so-lute-ly loved it - I've read it and re-read it countless times, don't know why it grabs me so, but it does. So Bitterblue has a tough two acts to follow...
I don't think this book works if you haven't read Graceling. Time line-wise, Fire comes first, then Graceling - and I thing you can read those two either way about, but Bitterblue definitely follows on from Graceling. B'blue is one of the secondary characters in Graceling and this book puts her centre stage. If you haven't read Graceling you won't understand the significance of having two different coloured eyes, you won't know how B'blue came to be on the throne, you won't know who some of the main supporting characters are, and most importantly, you won't know about Leck. And what Leck did is fundamental to understanding this book; it colours everything that happens.
The main storyline covers a shortish period of 5 months or so, and takes place in either the palace or its environs. It's essentially about how B'blue comes to realise that she is living in a bubble of mis-information and ignorance, and how she bursts that bubble, albeit with tragic, heartbreaking, unexpected and unintended consequences.
It's well written, although a couple of times I felt it could have been tightened up a bit; there's a fair bit about codes and ciphers (they're very important), a fair sprinkling of trauma - fights, assaults, descriptions of torture - that aren't gratuitously bloody or nasty, but also quiet times where friendships are created or strengthened. What came across for me is how lonely B'blue is - at one point she manufactures a reason to go to her healer, because that's the only place she can get some gentle human contact - and she has a great mass of inner grief and anguish that she has to cope with on her own -at times she really, really needed a hug.
This is a big book - 545 pages in my copy - all from B'blue's perspective. She's an engaging, tenacious, brave, thoughtful, clever young soul who holds center stage well, and has you caring about her, and most definitely rooting for her.
If you've read Graceling, you will enjoy this; if you haven't, read it, then enjoy being able to read this without the long wait!
Oh, one last thing, these books are listed in some places as Young Adult, but as a far from young adult I can say that they read well from more mature eyes!