Pastor Park is head of a religious investigation center that exposes cults and cult leaders. While looking into a suspicious new religion called ‘Deer Mount,’ he slowly uncovers clues that connect this cult to a series of mysterious cases of missing teenage girls when a body is found inside a damaged tunnel beams. He begins to uncover dark secrets surrounding this cult and its enforcer Na-han.

Ja-yoon is a high school student who struggles with memory loss after she endured some unknown trauma during her childhood. While trying to uncover the truth, she is unwittingly dragged into a world of crime and finds herself on a journey that will awaken many secrets hidden deep within.