The story follows Fei, who reminisces about his childhood at an orphanage run by his father. After finding a weak boy named Fiery, Fei promises to protect him. As the Qing dynasty declines amid turmoil, Fei joins the Black Tiger gang, led by Master Lui. Proving his bravery, Fei becomes Master Lui's fourth adopted son.

Determined to avenge his father's death, Fei infiltrates the gang with the help of his friends from the orphanage, who form an "orphan gang." They execute a plan to take down the Black Tiger gang by stealing keys to a secret vault and eliminating key members, including the gang leaders Black Crow and Old Snake.

Tragedy strikes when Fiery sacrifices himself to maintain Fei's cover. In response, Fei rallies the citizens against the gang, leading to a final confrontation with Master Lui. During their intense duel, Fei saves Lui from falling into flames, but Lui chooses to perish in shame rather than live as a coward.

With the gang defeated, Fei and the orphan gang take control of Huangpu Harbor. The film concludes with Fei establishing a martial arts school, symbolizing a new era of peace and protection for the city.