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.
Water Ng, a typical loser who likes to gamble and takes no responsibility is asked to take care of his ex-girlfriend Jik’s son, Yeung. With Jik tells him that Yeung is his son, and promised 100 thousand dollars, Water Ng agrees to be a father for one month. Soon he notices his son has Autism. He gets to understand the difficulties of raising a child along with special needs. With Jik's absence on the agreed date, Water Ng realizes why she brought him his blood. He finds his life goal while discovering Yeung’s talent on the racing field, then decides to get rid of the dissipated life and accompany his son spreading wings for the dream.