In an old noble household, an evil spirit named Gaehwa had long been masquerading as the revered guardian deity. But when the family’s heir, Yuhyeon, accidentally shatters the sacred vessel that sealed his power, Gaehwa’s tranquil existence crumbles. Facing the threat of exorcism at Yuhyeon’s hands, Gaehwa lies claiming that he can only pass on peacefully if his lingering grudge is resolved. When Yuhyeon asks what that grudge is, his hesitant answer leads him to a dangerously intimate misunderstanding that changes both their fates.