When the king of Aizasea is assassinated, eighteen-year-old Celvene is wise enough to keep her head down after witnessing the attack. As a circus mage, she has no business in politics—until the next ruler is selected by ritual, and Celvene is the sole soul capable of wielding the king's sword. Branded as the new queen, she sets out to prove that, while young and inexperienced, she is worthy of her crown. But her own kingdom stands in her way. With their mortal enemy continuing to strike the city, the people yearn for a more ruthless leader, and the brutish general Aleksandr is hellbent on seizing the crown for himself. On top of that, forbidden and deadly magic begins to corrupt Celvene's heart, threatening to unravel all she holds dear. As tensions rise and the horrors of war unfold, Celvene uncovers twisted secrets that could spell the death of her city. Will she survive long enough to fulfill her destiny as queen, or will the shadows of dark magic and war consume her?