After receiving approval from his superiors, young anti-narcotics policeman Chen Zheng (played by He Shengming) changed his identity and went undercover in a drug manufacturing factory. He cooperated with Jiang Hai (played by Wang Yiquan) outside the factory to plan to uproot the huge drug manufacturing and trafficking gang headed by He Yuanhua (played by Yu Entai). During this period, he was repeatedly tested and threatened by cunning drug lords.