"Criminal psychologist Seonkyeong receives an unexpected call one day. Yi Byeongdo, a serial killer whose gruesome murders shook the world, wants to be interviewed. Yi Byeongdo, who has refused to speak to anyone until now, asks specifically for her. Seonkyeong agrees out of curiosity. That same day Hayeong, her husband's eleven-year-old daughter from a previous marriage, shows up at their door after her grandparents, with whom she lived after her...