KANG Tae-sik, a former cop who was once the best man on the force, is now an infamous private detective who handles all kinds of dirty work from catching philanderers to collecting people's debts.
A young boy Hee-Joon is possessed by an evil spirit. Nun Yunia tries to save him, assisted by Nun Mikaela. Priest Paul attempts medical treatment, while Priest Andrew performs an exorcism to rid Hee-Joon of the spirit.