A familicide made Guan Hongyu, who was originally a carefree libertine, a wanted suspect on the run. As head of the criminal investigation department, his twin elder brother Guan Hongfeng vows to bring the truth to light. However, Guan Hongfeng was taken off the case because he is an immediate family member of the suspect, so he resigned indignantly. Guan Hongfeng later works as a consultant for the police. However, Mr. Guan, the "consultant," is actually played by the twins since the elder brother suffers from nyctophobia and can’t work at night. Since the two have very different personalities, they struggle to avoid being exposed by the police. At the risk of being discovered by Zhou Xun and all sorts of friends and enemies, they have managed to solve several important cases along the way.