Throne of Glass By Sarah J Maas

TWO MEN LOVE HER 

THE WHOLE LAND FEARS HER

ONLY SHE CAN SAVE THEM ALL

In a world without magic, an assassin is summoned to the castle. She comes not to kill the vicious king who rules from his throne of glass but to win her freedom. If she defeats twenty-three killers, thieves, and warriors in a competition, she will be released from prison to serve as the King's Champion. Her name is Celaena Sardothien. 

The Crown Prince will provoke her. The Captain of the Guard will protect her. And a princess from a faraway land will befriend her. But something evil dwells in the castle-and it's there to kill. When her competitors start dying one by one, Celaena's fight for freedom becomes a fight for survival-and a desperate quest to root out the evil before it destroys her world.