Bearing the grief of losing his family, Chor Au-kuen returns to the Kowloon Walled City in hopes of finding his long lost sister, only to find that the very place he grew up in has become a lawless no man’s land. Concealing his real identity as a Bajiquan master, Au-kuen creates a new identity and gets acquainted with the feisty and sassy Tiu Lan, the lady boss of a hair salon; Duen Ying-fung, a dentist; and But Tak-liu, a water worker. Au-kuen also impresses the highly skilled martial artist Yuk Bo-fung, who owns a store across the street from Tiu Lan’s hair salon. To restore law and order in the walled city, Au-kuen unites everyone to form a welfare association to resist the triads. However, this decision causes a clash between him and Bo-fung’s son Lung Shing-fu, who is an underground Muay Thai fighter. Just as things are finally getting on course, a key figure in a powerful triad mysteriously dies under the hands of a Bajiquan master. Au-kuen and Tiu Lan investigate, and their investigation leads them to Fa Man, the leader of a stripping dance troupe. But one discovery leads to another, and Au-kuen finds himself uncovering the truth behind his father’s death. The burden behind his family’s mystery may have been lifted, but not all is well. Au-kuen still carries one more painful memory that he’s unable to let go—that the one he trusts the most is actually a member of a gang of ruthless assassins.