Chan Chi-Lung has been an infiltrator in Cheung Mo-Hung’s Hong Kong triad gang for many years. After a failure of a recent negotiation by Lung with the other three local triad gangs on behalf of Hung makes the latter suspicious of Lung’s identity. Hung sets to wipe out every undercover cop in his gang and as a result many cops are caught and wiped out. Sensing the danger, Lung requests to put an end to his undercover career from his captain, Cheung. However, Cheung sends Lung to Mainland China to infiltrate a business of “Special Identity” trading instead.