A massacre has made Guan Hongyu, who was originally carefree and carefree, a wanted suspect on the run. As the captain of the Criminal Investigation Detachment, his twin brother Guan Hongfeng vowed to uncover the truth, but due to the principle of family avoidance, the police prohibited Guan Hongfeng from participating in the investigation of the extermination case. Guan Hongfeng resigned in indignation. Zhou Xun, who was transferred as the acting team leader, was under pressure to solve the case. In order to trace the whereabouts of Guan Hongyu, he designed to let the resigned Guan Hongfeng continue to participate in the investigation of major and important cases as an"off staff consultant". And everyone in the police force was concealed. Due to suffering from"dark phobia", Guan Hongfeng, the"consultant" of the police force, appeared during the day and night. In fact, he was played by two twin brothers, Bai Ye, who had vastly different personalities. The two brothers were constantly on horseback in the police force, carrying the danger of being discovered by Zhou Xun and people from all walks of life. They solved various major cases all the way, hoping to seize the opportunity to read the case files of the extermination case and uncover the truth, in order to restore their innocence