The ‘Beast Cop’ Ma Seok-do heads to a foreign country to extradite a suspect, but soon after his arrival, he discovers additional murder cases and hears about a vicious killer who has been committing crimes against tourists for several years.

Ja-yoon is a high school student who struggles with memory loss after she endured some unknown trauma during her childhood. While trying to uncover the truth, she is unwittingly dragged into a world of crime and finds herself on a journey that will awaken many secrets hidden deep within.