The Three Kingdoms are at war, but Meilin's father refuses to answer the imperial draft. Trapped by his opium addiction, he plans to sell Meilin for her dowry instead but when she discovers that her husband-to-be is violent and ill-tempered, she decides to take matters into her own hands. The very next day, she disguises herself as a boy and enlists in her father's place. In the army, Meilin's hard work brings her recognition, friendship and a growing closeness with Sky, a prince turned training partner. But as her kingdom barrels towards destruction, Meilin must decide who to trust: Sky, who inspires her loyalty and love; a sea dragon spirit with the power to grant her impossible magic; or an infuriating enemy prince who makes her question everything she once knew about her kingdom, her loyalty and her own heart.