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.

Talented superstar Jung Woo Jin has a disease causing him to remember everything, bringing stress. He meets Do Hye Soo, whose rare condition resets her memory monthly. Their encounter leads to unforgettable situations.