The Throne of Glass series is a romantic, epic fantasy series by Sarah J. Maas that encompasses many points of view yet centers around an infamous assassin named Celaena Sardothien, with a secret past as Aelin Galathynius, the heir to the throne of Terrasen. Set in a world plagued by parasitic demons called the Valg—who belong to another dimension and travel worlds via Wyrdgates unlocked by obsidian shards called Wyrdkeys—the series follows Aelin and her allies’ fight against the ancient evil who seek to conquer their world. While two of the three Valg Kings have been long since banished, the final Valg King Erawan remains—possessing the body of Duke Perrington, a loyal advisor to the King of Adarlan who is also possessed by a Valg Prince.

The series is set primarily in the Northern Continent of Erilea, which consists of many kingdoms: the Western Wastes, the Deserted Land, Ellwye, Melisandre, Terrasen, and Adarlan. Heir of Fire (2014) explores the Eastern Continent where faerie kingdoms—Doranelle and Wendlyn—reside, and Tower of Dawn veers toward the Southern Continent, home to the Torre Cesme (a school for magic healers) and where a government called the Khaganate reigns.