Mer is a drowser, or water mage, who has had to do terrible things in the name of her leader and his quest to take over other lands. She's run away and is trying to live her life on her own terms. Of course, the former spymaster finds her quickly, but wants her to assist him in a quest to bring down the kingdom. Chaos in the heist ensues, including references to the fey realm. What a great book about sacrifice and caring for others.