Once again, I love Kristin Cashore's writing, the depth of her characters and the intricacy of the world she creates. Bitterblue is a sequel to Cashore's Graceling and a companion to Fire. You can read it without reading the other two, but the story will be more satisfying and possibly less disturbing if you have some background.
It is now 8 years after Katsa killed King Leck and brought the country of Monsea out from the spell of his lying Grace. Leck is dead, but his life and lies plague Bitterblue as she struggles to rule a kingdom left broken by her father. Bitterblue searches for truth, but her entire country seems crazy and she doesn't know enough about the past to understand the people she rules. Her Counselors appear helpful, but their information doesn't add up.
In an attempt to find truth, Bitterblue sneaks out of the castle and enters her city disguised as a commoner. It is through her nighttime rambles and the new friends she meets that Bitterblue realizes someone is still trying to cover truth. As she struggles to uncover the mystery of her father's rule, Bitterblue learns more about her own strength and the strength of her friendships.
My only caution with this book is that Leck was an awful and demented villain. There are never vivid details about his crimes, but even the suggestion of them can be disconcerting. Even without details, I recommend this book for older and more mature readers. The story and writing is excellent, but Leck is disturbing.