Kingdom of Ash by Sarah Maas is the seventh book in her Throne of Glass series - a fantasy series set in the land of Erilea, which used to have magic and is fighting to get it back before an evil tries to enslave them all.
This final book in the series brings together all of the various characters and clans to fight against evil from another realm. It is hard to review the book without giving away spoilers from the previous six books.
If you are a fan of fantasy, strong female characters overcoming great obstacles, or young adult fiction you will enjoy this series. There are some great characters.
Maas, Sarah J. (2018). Kingdom of Ash. New York: Bloomsbury.