The migrant worker Cheng, Bruce Lee, travels to Thailand in search for work. He meets a group of Chinese workers and starts to work with them at the local ice packing factory. Mysteriously, members of the group start to disappear, which leads to workers demanding an explanation for the disappearance of their colleagues. In a hope to calm the workers, the management promotes Cheng to be foreman. But this is short lived when the disappearances continue. When Cheng starts to loose his trust and friendship to the workers, he begins to investigate the factory, looking for clues, and discovers that the factory is a conduit for drug trafficking. 

The Big Boss is the weakest of the four completed Lee films. But it became a great success and made Bruce Lee a huge star. Originally Golden Harvest gave Lee the supporting role in The Big Boss. But was amazed by Lee’s on screen presence and gave him the star role instead.