Lok, a Hong Kong undercover policeman, struggles in the conspiracy between gangs and the police in order to investigate the truth of gangs' drug trafficking.Lok, a Hong Kong undercover policeman, struggles in the conspiracy between gangs and the police in order to investigate the truth of gangs' drug trafficking.Lok, a Hong Kong undercover policeman, struggles in the conspiracy between gangs and the police in order to investigate the truth of gangs' drug trafficking.