Ryu Sung-Joon (TaecYeon), Ryu Sung-Hoon (Ha Seok-Jin) and Jo Eun-Ki (Jung Eun-Ji) become involved in a serial murder case involving jury members as the victims. These three individuals try to uncover the truth behind the deaths. Ryu Sung-Joon works as an enthusiastic detective. He is always determined to catch the bad guys. Due to his determination, his arrest rate is always among the top for detectives. His older brother is Ryu Sung-Hoon and he works as a judge. Ryu Sung-Hoon is a perfectionist and smart enough to have passed the bar exam with the top score and graduated at the top of his class at the Judicial Research and Training Institute. He is an upright man who does his best to impart a fair judgement. Jo Eun-Ki (Jung Eun-Ji) works as a social worker. She has a warm heart and is full of justice. She always puts people first and tries to be a reliable guardian to children who come from poor backgrounds.