It is AD 924, at the end of the United Shilla Dynasty. Continuous riots sweep the land ruled by a corrupted government. Evil forces are rampant and malicious demons roam the land. YI Kwak, born with the powers to see spirits, joins the royal demon hunting squad, 'Chuh-yong-dae' after losing his fiancée, Yon-hwa to evil demons. YI Kwak excels as the most talented warrior of Chuh-yong-dae and the royal squad seems to gain momentum as powerful fighters against the forces of darkness. Then one day, YI Kwak drifts into Joongcheon, the world of the dead through a strange shrine. Joongcheon, the intermediate world between Heaven and Earth, a place souls remain for 49 days, preparing for reincarnation.