In the 1980s, the golden age of Hong Kong's economic boom, the mainland was also reforming and opening up. In order to crack down on the triad forces in Guangdong and Hong Kong, O's Chief Inspector Wan Haiping sent undercover Li Si to get close to Hong Kong's largest triad gang and the "big sister" Zhang Yuqi of Lian Sheng. Unexpectedly, after a series of adventures, Li and Zhang secretly fell in love. Facing the future situation, Li Si planned to ask Zhang Yuqi to surrender, but Zhang Yuqi was unwilling to give up his power in Helian Sheng.
Purpose: To eradicate gangs and eliminate evil, it is the responsibility of the times.