"Shadow Scale" is a fantasy novel by Rachel Hartman, set in the same universe as her previous book, Seraphina. The story follows Seraphina as she navigates a world filled with dragons and political intrigue, focusing on her quest to find her long-lost half-siblings, who share her unique abilities. The novel explores themes of identity, belonging, and the complexities of family relationships. As Seraphina encounters various challenges, she learns more about herself and the true nature of her powers, ultimately striving to unite her family and confront the looming threats in her world.