Thirteen-year-old Heo Yeon Woo, the daughter of a high-ranking official, accompanies her mother to the royal palace to attend her brother, Heo Yeom's civil service examination congratulatory ceremony. By chance, she comes across Crown Prince Lee Hwon. They fall in love and Yeon Woo is chosen as the Crown Princess of Joseon.
Before they can marry, however, the Dowager Queen secretly orders her death, in order to install Yoon Bo Gyeong, the daughter of a family clan, as Crown Princess, thus securing more power for herself. She orders head shaman to cast a spell on Yeon Woo to stricken her with an unknown sickness. After dying, Yeon Woo is resurrected from her grave, but loses her memories. All believe her to be dead, including the Crown Prince Lee Hwon, who refuses to love another. Eight years later, Yeon Woo returns as a shaman named Wol (meaning moon). Meanwhile the young king begins to investigate the death of his love after seeing the grown up Wol. But he is fighting against time, because the queen's powerful political clan wants him removed from power.