In the later years of Goguryeo, Princess Muyeong, King Yeongryu’s daughter and Yeon Choong, Yeon Gaesomun’s son have a fateful encounter and fall in love for the first time. However, King Yeongryu is killed during the coup led by Yeon Gaesomun which turns Princess Muyeong’s heart cold as ice and makes her get involved in a plot to assassinate Yeon Gaesomun and Yeon Choong.