Celaena Sardothien, the world's most feared assassin, is offered an unexpected path to freedom: to win her liberty, she must outskill twenty-three convicted felons in a ruthless competition held at the king's behest. With no love lost for the tyrannical monarch, Celaena's objective isn't regicide; her eyes are set on victory. But as the tournament unfolds, sinister forces conspire within the castle's glass walls, claiming competitor lives one after another. To survive, Celaena must unravel the mysteries of the castle, navigate the dangers of a court rife with intrigue, and defy the iron grip of a king determined to see her fail. In this high-stakes, fantastical saga, ancient evil stirs and freedom is fought for with every cunning strike and whispered alliance.