"The Throne of Glass" is a young adult fantasy novel by Sarah J. Maas. It follows the story of Celaena Sardothien, a skilled assassin who is imprisoned in a salt mine. She is offered a chance at freedom by competing in a deadly competition to become the king's champion. As Celaena navigates the challenges of the competition, she uncovers dark secrets about the kingdom of Adarlan and its magic. The novel explores themes of power, loyalty, and identity, setting the stage for a larger series that delves into the complexities of its characters and their world.