" Mr.Jeon , it seems like someone is helping her" " I won't let you go , V " " So these many days V was not a girl , V was a boy " "These many days we have been fooled " A person with multiple personality disorder and is also a serial killer aka Kim Taehyung , 26 years old . Her life changed in a good way because of the guy , whom the world considered as maniac , sadist but to her eyes he was traumatized kid . Hwang Y/n , 18 years old . Jeon jungkook , officer from criminal branch who is so desperate to solve this case no matter what happens . Love between serial killer and the girl with Jungkook chasing behind .