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.

Days after a heart-fluttering encounter with a charming man, Yu Na Bi bumps into him again. This time, she's formally introduced to Park Jae Eon.

An extraordinary road to emotional healing opens up for an antisocial children's book writer and a selfless psych ward caretaker when they cross paths.