Hyo-joo (Ha-neul Kim) is a temporary teacher at a boys' high school and Hae-yeong (In-yeong Yu) is a fellow teacher who is the school board chairman's daughter. One day, Hyo-joo witnesses Hae-young locked in a passionate embrace with a boy and she starts feeling an inexplicable sense of humiliation towards Hae-yeong.

The story of Joseon's tyrant king Yeonsan who exploits the populace for his own carnal pleasures, his seemingly loyal retainer who controls him and all court dealings, and a woman who seeks vengeance.

Set in 1398. Kim Min-Jae (Shin Ha-Kyun) is the supreme commander of the Joseon Dynasty. He falls in love for the first time and for that woman he takes risks. Yi Bang-Won (Jang Hyuk) is the King’s son. He helped his father setup the Joseon Dynasty era, but he was not picked as the Crown Prince. He still holds ambitions of becoming the King one day. Jin (Kang Ha-Neul) is Kim Min-Jae’s son and the King’s son-in-law. Due to his position as the King's son-in-law, he is unable to take part in politics and only seeks out pleasure.