Ultra serious Ko Lap and carefree Kung Kwan are expert assassins.It's love at first sight for Kwan when he runs into the lovely Bin Yee. And Ko Lap continues to hide his love for Sau Yu, agent for him and Kwan. Unkowingly, Ko Lap executes a contract on Yee's father.

So goes to the U.S. to open a martial arts school. Around this time, many Chinese people were sold off to U.S. railroad companies, and were brutally treated by the Americans under the harsh working conditions. Thus, the American workers' hatred towards the Chinese immigrants is high. As a result, So gets into trouble with the Americans and the mob, and calls Master Wong for help.

In order to release his kidnapped sister, sports car mechanic, Chan Foh To, has to defeat a super-criminal street racer.