A teenage girl's visual remnants on the beginning of a juvenile murder case! But the girl has no clue that her testimony is completely ignored, with the case closed almost immediately. 12 years later, police Kang Oh Soo is surprised after receiving a card and letter with no information of the sender. And soon after, Oh Soo is asigned to investigate the death of a lawyer in his father's company. He finds the same card he has received from the scene of murder. As Oh Soo digs deeper, the man who painted the card appears. (Source: Viu)