Queen of Shadows by Sarah J. Maas
Celaena has lost everyone she cared about. In this fourth installment of the Throne of Glass series. We see Celaena return to her own continent for vengeance, and then to take back the kingdom that was taken from her. Celaena must confront her former master, savior, and condemner. She must again side with him to rescue her cousin from the grips of the brutal king. A cousin that was like a brother to her growing up, who would die to see her put back onto her throne. She has to place trust in people who could ultimately destroy her and everyone she loves. Celaena has to battle a friend, trapped in his own body but controlled by another. Trapped by his own father, "for his own good." She will fight for her people that were enslaved by the king, awaiting their true queen's return. Celaena has confronted her past and excepted her future, and what she has to do to reclaim her throne by any means necessary. Her journey has been followed by millions of people, eager to find out