蝴蝶Chan-woo, who has been studying to become a police officer for 5 years, joins his friends for dinner to ask for the money to apply for his exam and ends up getting drunk. He completely blacks out and wakes up not remembering what happened in his next door neighbor's room. Not only that, he finds a bloody corpse in the middle of the room. He hurries back to his room and tries to report the incident but he had forgotten his phone in the other room. But the door is locked and he has to resort to using a rope to swing to the next door room outside the window. Once the phone is recovered, he cannot go back because of a group of cultists who are evangelizing the neighbors in the hallway. He knows it’s the last day to apply for his exam and gets antsy as time is running out.