On a rainy night in 2006 in Nanshan Town, Jianghai City, Yang Yongshan, a policewoman on duty at the Nanshan Police Station, received an anonymous tip from a local resident about a fugitive. She went to discuss it with her mentor, Zheng Tianhua. In the end, the two decided to head out despite the rain, but Yang took a wrong alley, and her mentor was brutally slashed across the throat by a vicious criminal.
When Director Jiang of the city bureau heard about the case, he was furious. He spearheaded the creation of the bureau's first plainclothes squad and announced a special campaign to crack down on robbery, snatch theft, and burglary, as well as to capture thieves. After Yang earned the public's gratitude for catching a thief on a bus, Squad Leader Xu Guohao took notice of her and transferred her to the plainclothes squad. She also trained under Lu Zhiqiang, famed for his eagle eyes and lightning speed, learning the tricks of identifying and catching thieves. But Yang still desperately wanted to investigate the throat-slashing murder of a police officer. Taking an unconventional approach, she tailed a purse snatcher and unexpectedly discovered a secret fencing operation. It was frequented not only by all kinds of thieves but also by a few small-time vendors. The plainclothes squad then engaged in a cat-and-mouse battle with the gang of thieves and robbers. Who was the culprit behind the murder of the police officer all those years ago? Can Yang bring the real killer to justice?
