Cha Young Jin is a detective. She lost her friend 19 years ago to a serial killer. Cha Young Jin still carries guilt and trauma over the death of her friend. The serial killer case then begins again after 19 years. Cha Young Jin chases after the killer.
Also known as: 아무도 모른다 / Amudo Moleunda / Amoodo Moreunda / No One Knows