After noticing gaps in investigation methods for catching particularly heinous criminals, quiet, perceptive criminal behavioral analyst Song Ha Young (Kim Nam Gil) decides to explore the world of criminal profiling – a field previously untouched in South Korean policing. Alongside his supportive boss Young Soo (Jin Seon Kyu), Ha Young utilizes his newfound knowledge to delve into the darkest corners of the human psyche in the hopes of catching serial murderers. Ha Young must navigate skeptical law enforcement officers and the limits of his own mind as he strives to bring justice to the victims and prevent more lost life. This drama was inspired by the memoir “Those Who Read the Minds of Evil” by Kwon Il Yong and Ko Na Mu, which tells the true story of South Korea’s first criminal profiler.