A young woman, Miu Ling, who dreams of becoming a secret agent. One day she rescues an injured Agent Wing, who promises to make her his apprentice. From then on, her life is a roller-coaster of madcap adventures.

In 1970s Hong Kong, the Independent Commission Against Corruption (ICAC) was formed to bring down the corruption syndicate led by British government officials. One of its top investigators is Senior Investigator Lau Kai-Yuen, who brought down countless corrupted officials. Just as he thought stability and prosperity are within reach, a new era of greed and riches takes him into a new battlefield of corruption.