In 1978, the story begins in a cramped Hong Kong apartment where a violent altercation unfolds. Anthony Wong's character, Chan Chi-Leung, aggressively assaults a gambler named Keung, nearly killing him for refusing to lend money, and ultimately sets him on fire. To evade the police, Chan Chi-Leung destroys his identification documents and adopts the new alias Wong Chi Hang. This act of brutality marks the beginning of a dark and twisted journey that will span years.
The narrative then shifts forward to Macau in 1986, unveiling a chilling discovery: a bag filled with decomposing limbs washing ashore. Police officers Emotion Cheung Kam-Ching as Bull, Robert, King Kong, and Bo, arrive at the scene, quickly joined by their supervisor, Melvin Wong Gam-Sam's Inspector Lee. The officers examine the macabre remains and begin their investigation, setting the stage for a series of disturbing events.
Wong Chi Hang is shown working at the Eight Immortals Restaurant, where he receives a letter meant for Cheng Lam—the former owner of the establishment. Wong, who is shown tearing up the letter, is unable to take control of the restaurant legally because Cheng Lam is absent, and his signature is required. Meanwhile, the restaurant still technically belongs to Cheng Lam, creating a complex legal gray area. As the plot thickens, the officers take one of the severed limbs to a forensic analyst who identifies the remains as belonging to Cheng Lam’s mother-in-law, Helena Law Lan's character, revealing the gruesome extent of the murders.
Further investigations reveal that Cheng Lam has mysteriously disappeared, with his brother sending a letter to the police expressing concern. Wong's life takes a darker turn when he's caught cheating at Mahjong by a restaurant waiter. In a fit of rage, Wong violently stabs the waiter in the eye with a reception check spindle, beats him with a large soup spoon, dismembers his body, and turns it into pork buns—disposing of the bones in a dumpster. This gruesome act highlights Wong’s capacity for savage violence.
Inspector Lee orders the team to focus on the restaurant, leading to interviews where Wong maintains that Cheng Lam has "gone away." Meanwhile, Wong's interaction with Pearl, a waitress, turns deadly as he brutally beats, tortures, and rapes her before stabbing her with chopsticks and dismembering her as well. Wong’s actions become more erratic and terrifying, making him a prime suspect.
The police keep Wong under close surveillance, suspecting his involvement. Despite his suspicious behavior, Wong tries to cover his tracks by attempting to destroy evidence and crossing the border to China. However, he’s caught trying to escape and is detained. Inspector Lee begins to piece together the complex case, realizing that Wong murdered Cheng Lam and his entire family to steal his restaurant. Wong denies wrongdoing, but the police, including Wong Mei-Fan and others, escalate their efforts.
Torture becomes a method to extract a confession from Wong, which he finally provides after enduring days of brutal interrogation involving drugs, beatings, and physical abuse. Wong confesses that his murderous spree was rooted in debt and betrayal: Cheng Lam owed him a large sum of money, and after cheating at Mahjong, Wong took Cheng's wife and five children hostage. He then carried out horrific murders: killing Cheng Lam's son by cutting his throat, stabbing his wife, and murdering Cheng himself, along with the remaining children and Cheng's mother-in-law. Wong further revealed that he dismembered the victims and turned their bodies into pork buns, disposing of the remains in the ocean and trash where they were found.
In the end, Wong is returned to prison, haunted by his crimes. During his last moments, he attempts to end his life by slashing his wrists, a tragic culmination to a life marked by violence and brutality. Despite the mounting evidence, he dies before facing official charges, leaving the case shrouded in darkness. The narration reflects on his story, noting that his end prevented justice from fully catching up with his heinous acts while hinting at deeper scars left by his murderous past.
