The Kowloon Walled City in Hong Kong is a maze of stacked iron sheets, and the neon lights are filled with the smell of blood - the gangster Lord Long controls the sky here, police badges are used as bargaining chips, and human lives are like grass. Street boy Chen Xiaodao and his sister May were originally dependent on each other, but because May refused to be coveted by Lord Long, they were humiliated and suffered a mental breakdown. In order to save his sister and seek justice, Chen Xiaodao transformed from a young man who fought on the street to a protester step by step: he worked side by side with his gold-toothed friend A Fei, and under the guidance of the former policeman Old K (who was framed by Lord Long and whose daughter died tragically), he hid his talents and looked for evidence. He went around in the dark alleys of the city, prison bars, and dock containers, and uncovered evidence of Lord Long's smuggling and bribery of the police. This is not a lonely revenge, but a gathering of glimmers of light in the mud: Laundry Sister Xia, young Ajie, and justice inspector Sir Lin have joined in one after another, risking their lives to protect the chain of evidence that overthrows the darkness. When the neon lights of Kowloon City reflect the light of swords and the ink marks of ledgers, Chen Xiaodao is not only fighting against Lord Long, but also the evil that is rooted here. And hidden in every crack in the walled city is the character of the little people who will never bow their heads.
