Forsworn introduces readers to Erika, heir to the duchy of Leora in Kez. Branded as a powder mage who has sworn never to use her powers in return for not having to face execution, Erika has been training to fulfill her duty as a Kez noblewoman for most of her life. When a young powder mage on the run is discovered in the forests of her family's land, Erika makes the fateful choice to help the girl and put her life and that of her family in danger in order to do so. Can Erika and her companions help the girl Norrine to escape the Longdog mage hunters or will she face the headman after all?

Forsworn is an excellent introduction to the woman who would later become the wife of the powder mage Tamas. It gives insight to the situation of powder mages in Kez and why Erika would later lose her life for that crime. While I haven't read much of Promise of Blood yet, I loved getting to see such a strong female character in a series that seems to be largely dominated by men. It did have a bit of a bittersweet note knowing what eventually becomes of Erika but I really enjoyed getting to see a bit of her story.