Back in the 1990s, the citizens of Seoul were gripped with a paralyzing fear after a series of brutal attacks and murders occurred. A mysterious figure dubbed ‘Red Cap’ was stalking women on the streets then killing his prey, seemingly without provocation. His habit of striking at random made it impossible for the detectives to predict his next move. At the top of their minds is what could be triggering him. Aware of the American F.B.I. and its successful use of criminal profilers to identify serial killers, the head of the Criminal Behavioral Analysis team, Kook Yeong Su recruits Song Ha Yeong, a quiet, reserved, incredibly perceptive former detective for his team. He believes using this new psychological method will give the police an edge in capturing 'Red Cap' and ending his killing spree. Homicide expert Yun Tae Gu and her officers question the value of this approach and are resistant to entering such uncharted territory. To quell their scorn they need to convince that this radical crime-fighting approach will increase their arrest rates. Does Song Ha Yeong have the ability to gain the trust of callous criminals while seeing through them? Is he clever enough to outwit them? But more importantly, does he possess the emotional fortitude to withstand the process? (Source: Viki; edited by Lee C) ~~ Adapted from the autobiography "Through the Darkness" (악의 마음을 읽는 자들) written by Korea's first criminal profiler Kwon Il Yong and journalist-turned-author Ko Na Mu, depicting some of Kwon's field experiences.