Yoon Gap, a respected palace official, becomes possessed by the ancient Imoogi spirit, threatening the royal court's safety. As dark rituals unfold, Minister Suk-joo manipulates events from the shadows to forcibly restore Yoon Gap’s body, intensifying palace intrigue. Meanwhile, Yeo Ri, a shaman with latent spiritual powers, confronts her destiny to combat the malevolent forces invading Joseon’s palace, blending fantasy, suspense, and political drama in a haunting saga.