Empire of Storms by Sarah J. Maas
Synopsis from GoodReads:
The long path to the throne has only just begun for Aelin Galathynius. Loyalties have been broken and bought, friends have been lost and gained, and those who possess magic find themselves at odds with those who don’t.
As the kingdoms of Erilea fracture around her, enemies must become allies if Aelin is to keep those she loves from falling to the dark forces poised to claim her world. With war looming on all horizons, the only chance for salvation lies in a desperate quest that may mark the end of everything Aelin holds dear.
Aelin’s journey from assassin to queen has entranced millions across the globe, and this fifth installment will leave fans breathless. Will Aelin succeed in keeping her world from splintering, or will it all come crashing down?