“I’ll make the world pay at your feet” Malgeum, a young woman taking punishment for the noble family’s daughter, encounters Crown Prince Jeong-mun one fateful day. He tells her the secret of her birth, and he wants her to become his sword. Malgeum lost everything, but to survive, she agrees to his request. “Your name will be Jin Seo-ha from now on. You will be the heir of the prime minister.” Her first assignment: to become a man, take revenge on her father and collapse her own clan. Only then can she fulfill her purpose to help Jeong-mun ascend to be king. An unexpected journey so acute, and inherently dangerous, only brought the two of them closer with deeper feelings…