The Throne of Glass Series
by Sarah J. Maas (Author)
In a land without magic, where the king rules with an iron hand, an assassin is summoned to the castle. She comes not to kill the king, but to win her freedom. If she defeats twenty-three killers, thieves, and warriors in a competition, she is released from prison to serve as the king's champion. Her name is Celaena Sardothien.