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

A criminal known as Thunderbolt is imprisoned and facing execution. Into the next cell is placed Bob Moran, an innocent man who has been framed and who is in love with Thunderbolt’s girl, without knowing of their relationship. Thunderbolt hopes to stave off the execution long enough to kill young Moran for romancing his girl.