Cheung Sung-bong is an officer of the Regional Crime Unit who worked in the front line for many years and cracked many major cases. However, he is seen as an outcast due to his extremely righteous character which affected his career, but his protege, Yau Kong-ngo, respects him as a good officer although Yau does not completely agree with Cheung's overly hard-boiled style and believes in taking shortcuts. Yau manage to reach up to Cheung's level. However, fate unexpectedly brings them to different paths and pits them against one another.