One a bright spring day before a school trip, Semi, falls asleep on one side of the classroom, and suddenly awakens in tears over an ominous dream. She runs to Ha-eun, who is in the hospital after injuring her leg in a bicycle accident.
No.1 subscribed live streamer, ‘IDOL’ specializes in criminal profiling and covering crime-related mystery cases. One day, ‘IDOL’ streams about an unsolved serial murder case and ends up unveiling the truth to some dark secrets through his channel.