Arrival in Thailand
Cheng Chao-an, a young man from mainland China, arrives in Pak Chong, Thailand, to join his extended family and begin work at an ice factory. Upon arrival, he witnesses a street altercation where his cousin Hsu Chien defends a younger sibling from local bullies. Cheng, despite the urge to intervene, chooses restraint, bound by a promise made to his mother never to engage in violence. As a symbol of this vow, he wears a jade amulet around his neck.
Cheng soon settles into the routine of the factory job. During one shift, a block of ice is accidentally broken, revealing a hidden bag filled with white powder. The substance is clearly illegal drugs. Two of Cheng’s cousins, who find the bag, are asked by the factory manager to meet later that night. What follows marks the beginning of a grim chain of events.
The Disappearances
Unknown to the rest of the workers, the factory serves as a front for a drug trafficking operation orchestrated by the enigmatic Hsiao Mi, known locally as the Big Boss. When the cousins refuse to cooperate with the illicit enterprise, the manager orders their murder and the disposal of their bodies to keep the operation hidden.
Hsu Chien and another cousin, Ah Pi, grow suspicious and go to Hsiao Mi’s residence to inquire about their missing relatives. When their questions threaten to expose the operation, they too are killed after a brutal altercation with Hsiao Mi’s enforcers. Their absence causes unrest among the factory workers. Suspecting foul play, they initiate a strike, which quickly escalates into a riot. A group of hired thugs is brought in by the management to subdue the protesting laborers.
During the skirmish, Cheng’s jade amulet is accidentally torn from his neck and shattered. The breaking of this token marks a turning point. Enraged, Cheng unleashes his repressed fighting ability, singlehandedly defeating the thugs and restoring order. As a reward and to calm tensions, the factory manager promotes Cheng to foreman and invites him to a private dinner with the boss.
Betrayals and Discoveries
While the family celebrates Cheng’s promotion, only Chow Mei, his cousin, mourns the unresolved disappearances. Cheng promises to investigate. His new status allows him to restore productivity among the workers while preparing to meet the elusive Big Boss.
At the dinner, the manager informs Cheng that the boss is unavailable due to an out-of-town meeting. A group of women joins the gathering, and Cheng becomes heavily intoxicated, eventually spending the night with Sun Wu Man, one of the women. The next morning, Chow Mei sees him leaving a brothel and is visibly disappointed. Cheng realizes he has failed to fulfill his promise to seek help, leading to growing resentment from his family. Despite their disapproval, Chow Mei defends him.
Sun Wu Man warns Cheng that his life is in danger and exposes Hsiao Mi’s role in the drug trade. Shortly after, Hsiao Mi’s son, Hsiao Chiun, murders Sun. Determined to find the truth, Cheng sneaks into the ice factory at night. Inside, he discovers not only the hidden narcotics but also the remains of his murdered cousins, including severed heads embedded in ice blocks. Before he can flee, he is confronted by Hsiao Chiun and a gang of thugs. Cheng fights them and emerges victorious, killing them in the process.
Revenge and Resolution
Cheng returns home, only to find his family slaughtered and Chow Mei missing. Grief-stricken, he mourns beside a river and vows to take revenge, even if it costs him his life. He then infiltrates Hsiao Mi’s mansion, battling his way through more guards. A sympathetic servant frees Chow Mei from captivity, allowing her to escape and contact the local authorities.
Cheng confronts Hsiao Mi in a final showdown. After a brutal fight, he defeats the Big Boss by deflecting a thrown knife with his shoe, fatally striking his opponent. The confrontation ends just as the police arrive with Chow Mei. With the threat eliminated and Chow Mei safe, Cheng surrenders peacefully. He is taken into custody and escorted away, leaving behind the ruins of Hsiao Mi’s criminal empire and the loss of his own shattered family.