Yun Gap is a government officer who works in the palace. He has a good reputation and has a handsome appearance. One day, Yun Gap's body becomes possessed by an Imoogi creature. Soon afterwards, people start talking about him as if he has lost his mind. The Imugi who possessed Yun Gap is related to Yeo Ri, whose first love was Yun Gap. Yeo Ri is the only granddaughter of a famous shaman. She has a divine gift but refuses to accept her fate as a medium of spirit. Instead, she works as a glass craftswoman. The Imugi needs Yeo Ri's body to ascend to Heaven, but Yeo Ri won't allow it. After Yun Gap becomes possessed, Yeo Ri enters the palace filled with powerful female ghosts and evil spirits. Meanwhile, King Yi Seong is a reformist monarch who dreams of a strong Joseon nation. Weird and terrible incidents continue to take place within the palace. These are related to the powerful female ghosts who hold a grudge against the royal family. To get rid of the ghosts, Yun Gap, Yeo Ri, and King Yi Seong search for the secret of the female ghosts.
