Based on the novel of the same name by Hyun Go-Woon, the series tells the romance of a Goryeo prince and a Balhae princess, both of whom were deemed cursed by their families due to their prophesied fates. Although born a prince of Goryeo, Wang So was exiled from the palace at a young age due to a prophecy that foretells he will bring bloodshed to the royal family. By chance, he meets Shin Yool, the last princess of Balhae who was prophesied to become the "light of another nation." Brought together by a whirlwind marriage, they eventually fall in love and help each other confront their own fates.