To avenge her family, Duchess Iona cuts her hair and disguises herself as a man, infiltrating the empire's most elite knightly order. By a twist of fate, she is partnered with Zephyr, the strangest boy in the ranks—a "monster" hiding his demonic bloodline. As a cataclysmic war sweeps the kingdom, Zephyr reveals a near-maniacal possessiveness over her, while she struggles in a maelstrom of vengeance, lies, and forbidden emotions. When her identity as a woman is exposed on the battlefield, will the half-demon who has sworn to claim her become her sharpest sword, or will he be the one to push her into the abyss of destruction? Loyalty and betrayal, love and possession—all will face their final judgment in blood and fire.
