Living in Hong Kong in 1986, Kai San, Anthony Wong, works for Kwan Shing Fui-On, a powerful figure who rules a web of crime and influence. Kai begins a dangerous affair with Kwan’s wife, a secret that could topple the uneasy balance of power. When Kwan catches them, the wife accuses Kai of assault, and a brutal confrontation follows: Kai kills Kwan, the wife, and a henchman. In the heat of the clash, he is about to strike Kwan’s daughter Lily Angel Wong Chui-Ling as well, but the plan is interrupted. With this act of violence, Kai becomes a wanted convict and flees to South Africa, leaving behind a trail of fear and suspicion.
Ten years pass. Kai resurfaces as a chef in a Chinese restaurant, where the atmosphere is tense and hostile. His boss, Kei Lo Meng, and Kei’s wife Cheung Lau routinely bully him, creating a fragile sense of danger in the kitchen. Lily (the same Lily who is Kwan’s daughter) is now a young flight attendant who visits Kai’s restaurant; her presence triggers a sense of unease, and she grows sick whenever she is near him. The story widens its circle as Kei, hoping to stock up on cheap meat, travels with Kai to aZulu tribe. There, a raw ceremony is performed around sick members, and Kai’s path crosses with a dying infected person. In a brutal moment, he rapes and kills her, and soon after, he develops a fever. Doctors reveal a grim truth: Kai has Ebola, but he is one of the rare individuals immune to it, turning him into a living carrier capable of spreading the disease through bodily fluids.
Kai’s danger deepens when Kei’s wife speaks of eliminating him. Kai overhears and attacks her; Kei returns, trying to defend his spouse, but Kai kills him as well. The terror escalates as Kai rapes Kei’s wife, rips out her right eyeball, and kills her. When the wife’s cousin stops by, Kai also murders him. He dismembers the corpses and serves them to the restaurant’s customers as hamburgers, a chilling display of his capacity for violence. Lily and her boyfriend realize who Kai is, but the police are hampered by a lack of concrete evidence. The epidemic grows as more people fall ill, and Kai uses Kei’s money to return to Hong Kong, where he has sex with two prostitutes who also fall sick, confirming the spreading threat.
With collaboration between South African and Hong Kong authorities, and Lily’s persistent efforts, the link to Kai becomes clearer, tying the outbreaks to him. Kai then reconnects with Har, his former lover who now has a husband and daughter. He buys Har from her husband and continues to propagate the virus, spreading it to many, including Lily. He resumes their relationship, and Har, realizing the gravity of Kai’s infection, tries to leave him. In a desperate turn, Kai grabs a knife and takes Har’s daughter hostage to keep the authorities from seizing him. He also spits on bystanders, fueling chaos around him. In the grim finale, as Kai struggles to escape, he murders Har’s daughter, leaving the police with little choice. Inspector Yeung Vincent Wan Yeung-Ming confronts Kai and, in a final act of retribution, sets him on fire and shoots him, ending the threat in a violent blaze.
