Katsa is a Graceling, a dangerous one. In the Seven Kingdoms, sometimes children are born with mismatched eyes, a sign that they have been blessed (or cursed) with an extreme skill in some area...climbing trees, baking, juggling, mind reading, killing. This last one is Katsa's Grace and she has been manipulated into using it to carry out her uncle's (the king of one of the Seven Kingdoms) orders, mainly killing and torture.
But then during a mission she encouters a man, Po, who is obviously Graced in combat skills and it was a tough fight for her to win. Though she should have killed him she let him live. This decision would alter the course of Katsa's life permanently...and she's not at all sure it's for the best.
Okay, I LOVED this book. Loved it. I loved Katsa and Po and how their relationship develops. I love how Katsa herself changed and things she learned about herself on her journeys. The only thing I didn't love is that it seemed that Katsa was so completely anti-marriage that it almost felt like the author was trying to tell me what she thought about marriage and it probably only caught my attention because I am all about marriage. :) Still, that's one minor thing compared to the whole wonderfulness of the story. Kristin Cashore has apparently two more books planned that are set in this world. I can't wait.