Zhang Huiling is a veteran plainclothes detective leading a team from the local police station specialising in catching pickpockets and fraudsters. In seven years, Zhang has arrested over 1,600 criminals on the streets. One of his techniques is to use a minicam to record evidence as he follows suspects. One day, after arresting a thief stealing money from a car, he becomes suspicious of the car's owner, Li Wuyi, and follows him, exposing a scam in which children are used to extract money in fake car accidents. While doing so, Zhang hears that a famous thief, Golddigger Zhang has arrived in town. Among other cases, Zhang Huiling tracks down a husband-and-wife team running a scam of exchanging fake 100-yuan notes for small change. One night, he becomes involved in the case of of a young child, Xiao Yaer, who's repeatedly run over in an alleyway. Golddigger Zhang then texts Zhang Huiling and says he plans to steal RMB100,000 (US$16,000) during the next three days and will donate the money to Xiao Yaer. Zhang sets out to hunt him down in a battle of wits.