One early morning, a body of a teacher is found on the campus of Eungbo High School. Is it a suicide or a murder? Min-gu, possessed as a child, has become a teacher at the school. Eun-chan, traumatized by an event that took place during his high school years, has lost memory of the event and became a priest in search of the truth. Min-chul, whose girlfriend died 8 years ago, is still searching for the killer, now a detective. When three high school classmates reunited after 8 years, strange things start to happen.