Empire of Storms by Sarah J. Maas is a fantasy novel in the Throne of Glass series. It follows Aelin Galathynius, who is building alliances across kingdoms to prepare for a massive war against the dark forces of Erawan and the Valg army.
As the threat grows, Aelin and her companions—including Rowan, Aedion, Lysandra, Elide, and Manon Blackbeak—work separately and together to gather power, uncover ancient secrets, and secure support from different regions.
Meanwhile, Dorian, the young king of Adarlan, struggles with his dark magic and personal trauma while trying to protect his kingdom from invasion.