Wong Fei-Hong and his once-rival, now friend, find themselves and their martial arts schools pitted against a rival school which uses a Kung Fu expert from the North to do their dirty work.

A Kung Fu master finds out that an opium den is destroying the lives of the town he lives in, and vows to put an end to the den, but first he must try to defeat the strongest enemy he has ever faced: his addiction to the drug itself.

During the shut down and destruction of the Japanese test camp Squadron 731 in Manchuria, a soldier becomes infected with a virus developed during the camp's testing and risks spreading it into Japan on the train ride home.