Schizophrenic Xihui (played by Nick Cheung) is released on parole. Back then, he hacked dozens of people to death, but was arrested by a policeman (played by Liao Qizhi). 29 years later, the old gang leader is dead, and there are two candidates for the new gang leader: Porcupine and Peter (played by Patrick Tam). The former is lustful and timid, and the latter is quite scheming. The uncles want to support Porcupine to take over, and let him pick up Xihui from prison and win him over to fight against Peter. Porcupine is preparing to welcome Xihui, but the latter not only does not appreciate it, but also rescues the three people that Porcupine wants to deal with in person: pimp Dant (played by Wong Jing), prostitute Dafeng (played by Mo Xiaoqi), and Xiaofeng (played by Meng Yao). It turns out that Dafeng is a prostitute under Dant and has been raped by Porcupine. When she learned that her mentally retarded sister Xiaofeng was abducted to Hong Kong, she rushed to rescue her without hesitation. For this, she offended Porcupine. Xihui takes them back to his home. Xihui's mother (played by Paw Hee Ching) has dementia and can't recognize her son, but she feels very close to him. After that, Xihui and Dafeng develop feelings for each other, but he becomes the focus of the gang and is targeted by the gun king...