Shin Ha-Ru (Jung Yong-Hwa) works as a neuroscientist. He comes from a family of doctors spanning three generations and is wealthy from inherited property. Shin Ha-Ru is a self-assured person who acts and speaks according to his convictions, but he has no mercy for people he considers scum. Geum Myung-Se (Cha Tae-Hyun) works as a detective. He acts and speaks gruffly toward people, which leads those who don’t know him to assume he might be a corrupt cop. In reality, Geum Myung-Se is a kind and upright detective. He was once married to Kim Mo-Ran (Ye Ji-Won). She has a particularly strong sex drive. Shin Ha-Ru and Geum Myung-Se solve criminal cases together with the help of hypnotic investigator Seol So-Jung (Kwak Sun-Young).