The next morning , she is discovered dead on a rooftop , shocking the residents and pressuring the incompetent police to find the killer .
Late at night , Do - joon follows a high school girl named Moon Ah - jung into an abandoned building .
The next morning , high school girl is discovered dead on a rooftop , shocking the residents and pressuring the incompetent police to find the killer .
Late at night , Do - joon follows a high school girl named Moon Ah - jung into an abandoned building .