Two people are brought together by their connection to a horrible event and work together to solve the case. Choi Moo Gak lost his younger sister, Eun Seol, in a senseless killing known as the “Bar Code Murders” three years ago. Devastated by the loss, Moo Gak becomes a police officer to try to catch the perpetrator, who is still at large. He meets Oh Cho Rim, a woman who survived the event but lost her memory and acquired the unusual ability to visualize smells. Can Moo Gak and Cho Rim work together to catch the “Bar Code Murderer” and heal each other’s wounds?