Chief Inspector Wen Fang (played by Leon Lai) of the homicide squad has become irritable and eccentric since his wife was murdered two months ago, often being reported for roughing up suspects. During the investigation of a murdered prostitute, Wen Fang meets Senior Inspector Ji Shaoqun (played by Ren Xianqi) from the district’s homicide unit, and he sends his men to help him recover a stolen mobile phone. The investigation into the prostitute's murder intertwines with a gunfire incident, prompting a joint operation between the homicide squad and the unit investigating the gunfire case. However, the ambush operation is leaked, leading to a fierce battle in a teahouse. One of Wen Fang’s brothers is severely injured, and Officer Ji soon arrives, only to be shot by the suspect while assisting in the pursuit. The suspect in the prostitute's murder case is initially narrowed down to Officer Gao Xiangan (played by Liao Qizhi), leading to Wen Fang's suspension for protecting his subordinate. With the help of many brothers, the homicide squad catches the suspect described by Xiangan who wore a fishing hat, and the suspect confesses to the murder. During the process of escorting the suspect, he manages to escape by injuring Xiangan while in handcuffs. This series of incidents leads Wen Fang to doubt members within the police force, and with the assistance of Officer Xiao Mei (played by Ye Xuan), he finally uncovers the hidden 'Old Ghost' within the police ranks...
