"Crown of Midnight" is the second book in the Throne of Glass series by Sarah J. Maas. It follows the story of Celaena Sardothien, a skilled assassin, as she navigates the treacherous political landscape of the Kingdom of Adarlan. After becoming the royal assassin, Celaena faces moral dilemmas and dangerous missions that test her loyalty and strength. As the plot unfolds, Celaena uncovers dark secrets about the King and the true nature of her assignments. The book explores themes of friendship, betrayal, and the struggle for freedom, while introducing new characters and deepening existing relationships within the series.