“I will make the world kneel at your feet.” Malgeum, a young woman who takes punishments in place of the noble family’s daughter, one day encounters Crown Prince Jeong-mun. He reveals the secret of her birth and asks her to become his sword. Having lost everything, Malgeum accepts the offer in order to survive. “Jin Seo-ha—that will be the name you are called from now on. And you will become the heir to the prime minister.” Her first mission: to disguise herself as a man, take revenge on her father, and bring down her own clan. Only then can she help Jeong-mun ascend to the throne. On a journey as dangerous as it is intense, the two of them grow ever closer, their feelings deepening with each step…