Lao San, is a retired Marine veteran who lives in his world of innocence and optimism due to a brain injury. He assumes the role of a dedicated vigilante and fights people whom he considers bad.

Two brothers witness their mother's murder by a drug lord. One becomes a cop, the other a drug lord. Years later, they face off on opposite sides of the law.

This film tells the story of a female SWAT officer from Lingbei City who goes undercover to infiltrate a cross-border criminal gambling syndicate. Xiao Chen successfully infiltrates the “Geluxiban” organization and, working in coordination with the task force, helps dismantle the criminal operation and captures the ringleader, Xiao Yang. However, at that moment, Xiao Chen discovers that behind all the crimes lurks a mysterious figure known only as “Brother Tiger.”

A biochemistry expert is enlisted to probe a string of water-borne killings blamed on a “kappa.” As the case deepens, he discovers ties to his long-missing father and a professor conducting illegal human experiments.