Wei Shen is an undercover cop working for the Hong Kong Police Force. He is tasked to infiltrate the Triads and take down a dangerous criminal organisation - the Sun On Yee. Going undercover, Wei Shen must prove his worth by eliminating the gang's enemies and move up the organization until he finds himself in a position of power.

Torn between his loyalty to the badge and the code of the triads, Wei Shen will risk everything as the lines between truth and honor become permanently blurred.