In 1980s Hong Kong, troubled youth Chan Lok-kwun, a mainland refugee, struggles to survive in the Kowloon Walled City by joining underground fights. Betrayed by crime boss Mr. Big while trying to buy a fake ID, he steals drugs from him and seeks refuge in the Walled City, where he encounters Cyclone, a compassionate yet authoritative crime lord.
Working in the morgue, a hardworking forensics expert and his assistant are suddenly accosted by masked intruders who demand access to a body involved in a recent crime.
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.
