Kei is a cop goes undercovered as a gangster, the only person who knows his real identity is his boss- Chief Inspector Wong. One day, the cops destroy a big group of gangsters in town due to the information that provided by Kei, and which lead Kei’s gang boss started to suspect him. In the meanwhile, Chief Inspector Wong betrays Kei for his own good, to sell out the evidence of the gangster group that Kei got to Kei’s gang boss, and told him Kei’s real identity. Kei needs to struggle with both law and evil party without any support on the way.