When Shengyuan (played by Dong-wook Kim) was still a prince, he unexpectedly met the daughter of Minister Shen (played by Yeo-Jeong Jo), Huayan, and fell in love at first sight. However, his mother, for her own political ambitions, betrothed Huayan to his half-brother as a queen, prompting Shengyuan to leave his homeland. Huayan was originally in love with a servant, Quan Yong (played by Min-jun Kim), and she learned that she was to be taken to the palace as a concubine. In a desperate attempt to protect her lover, she fled but was caught by her father and had to enter the palace to ensure his safety. Five years later, the prince fell seriously ill; under the schemes and arrangements of his mother, Shengyuan became a puppet emperor. In the coup, Huayan's father was persecuted and executed by his mother. At this time, Shengyuan met Huayan, who had become the emperor's sister-in-law, and the constraints of power intensified his taboo desires. Meanwhile, the household servant Quan Yong, who had failed to escape and protect his life, was castrated by Minister Shen. To avenge his suffering and reach the heights of power, he entered the palace as a eunuch, enduring humiliation to survive. Set against the backdrop of court struggles, the fates of these three individuals intertwine, brewing a tragedy amid conflicts of love and power, passion and hatred.
