You're a new at the town/city called "Mujin", you were the new transfer neighbor between ye-bun and jang-yeol's house, you always see them together they sometimes bicker but you didn't mind, there are many people's dying bc of a serial killer... Detective jang-yeol is always in his balcony look out if there are something unfamiliar or weird walking around at night he always observes One night,you were walking home from your work late at night and you saw him drinking coffee looking at observing