Synopsis
The series retells the love story between Princess Pyeonggang and On Dal, who are characters in a classic Goguryeo folktale. Princess Pyeonggang (Kim So-hyun) who was born as a princess but raised to be a person who killed a sinner also known as Yeom Ga-jin, an ambitious woman who dreams to re-establish the status of Goguryeo and be the first female Taewang of Goguryeo. However, she uses On Dal's (Na In-woo) feelings for her to achieve her goals.
