In the last "Big Boss" (AKA "Fists of Fury"), Cheng Chao-On was arrested after killing Hsiao Mi, "The Big Boss." In this unofficial sequel, his brother, Cheng Chao-Chun, visits his brother in Thailand, finds a job at the same ice factory that his brother worked at and avenges the death of their father.

Chan is asked by a young, wealthy lady to take her sick brother to a particular doctor in order to be cured. To reach this doctor, Chan and a handful of travelling companions must pass through bandit-infested wild country. They meet and kung-fu-fight several gangs of thugs along the way.