Li Jing

A drug cartel boss is arrested in a raid and coerced into betraying his former accomplices as part of an undercover operation.

Sun Wukong is a monkey born from a heavenly stone who acquires supernatural powers. After rebelling against heaven and being imprisoned under a mountain for 500 years, he later accompanies the monk Xuanzang on a journey to India. Thus, according to legend, Buddhism is brought to ancient China.

During the warlords era in China, a village located in rural area called Pucheng fell into dangerous situation when its government allocated all its military force to the front line, the cruel commandant Cao from the enemy troops arrived the village and killed the innocent, the guardians of Pucheng were desperate to fight against Cao for justice and to protect their homeland.

When Hong Kong is rocked by multiple gruesome murders, the police forms a task force to investigate. Jun, once a brilliant detective who suffered a mental breakdown, begins his own investigation. Eventually, the police learn that the murder victims are all suspects of cold cases being rubbed out by a figure known as "The Sleuth". Now, Jun and a detective from the task force are on a race against time to beat the brutal killer at its own game.