Grave Mercy is one of the best historical fantasy novels I have read. Robin LaFevers is an amazing storyteller and readers will be captivated with the story of Ismae and the daughters of Mortain. Grave Mercy really does have everything readers could want: murder, betrayal, romance, and assassin nuns. Yes, you heard me right, assassin nuns.Ismae is a hard character to like in the beginning. She is cold, standoffish, and a bit cruel. She has been hurt by every man in her life and she is unwilling to see that a man could be a good person. The convent is her way to escape. They offer her a way to get back at all the men who hurt her and all the men who could hurt her in the future. The nuns train her in the art of death and they help her grow. Her true growth starts once she leaves the convent though. She becomes open to friends, romance, and a life outside her role as a daughter of Mortain. Duval is one of the main reasons for Ismae's growth. He is kind, strong, brave, and he shows Ismae that men can be gentle and kind. It's something Ismae has never seen and never believed. It changes not only the way she views men but also the way she views the world. De Lornay, Beast, Isabeau, and Anne are also great helps to Ismae and each one is a great character. Beast was probably my favorite though. The story of Mortain and his daughters is fascinating. It's a tale that has a feeling of an old myth but it is completely unique. Throughout the book new secrets are revealed about Mortain and the roles of his daughters. The convent keeps many things from their novices and each new truth is shocking and only gets readers more enraptured in the story. I also thought it was cool how some of the well known myths were retold in Grave Mercy with little twists.The plot does take some getting into. Ismae's training at the convent is not exactly exciting and the story only really starts to pick up after she leaves to begin her tests. From that point on the book is impossible to put down. New betrayals are revealed with practically every chapter. Nobody can be trusted in the court of Brittany and Ismae does not lack people to take care of according to the orders of Mortain. Every page is full of scandal, betrayal, and some sweet and sexy romance.Overall, Grave Mercy is an amazing start to His Fair Assassin series and I look forward to reading more from Robin LaFevers in the future. I certainly won't mind reading more about Duval.