Special ID: Dragon has been an infiltrating cop in Hung's Hong Kong triad gang for many years. After a failure of a recent negotiation by Dragon with the other three local triad gangs on behalf of Hung makes the latter suspicious of Dragon's identity. Hung sets to wipe out every undercover cop in his gang. Sensing the danger, Dragon requests an end to his undercover career from his captain, Cheung. However, Cheung sends Dragon to Mainland China to infiltrate a business of "Special Identity" trading instead. The business is run by Hung's best protégé, Sunny, who was Dragon's previous buddy in the gang. Cheung promises to reinstate Dragon's police identity in conclusion of the mission once Sunny's business breaks down. Dragon agrees, and joining him are local police officers Lei Peng and Fang Jing from the Mainland Chinese police force.