A young maniac starts a terrorist spree in Hong Kong. The police do not manage to catch the culprit. When the wife and child of inspector Tsui get wounded in one of the explosion, he intends to catch the dangerous maniac.

Chang is known for his lone swordsman and hero movies and strangely The Weird Man still reflects this. Cheng plays a righteous, beheaded priest with supernatural powers that returns from the dead to wreak havoc against one of the corrupt kingdoms, making Cheng a heroic swords-ghost.

Chin Siu Ho plays a young man who believes himself to be an orphan. Until one rainy night when he and three different men find themselves taking shelter from the storm in the same place. Here the man who raised him tells him at last the story of who his parents were. His father (Lu Feng) was a great swordsman trying to dispel rumors of a wrongdoing and return a lost sword to its rightful owner. Kuo Choi and Chiang Sheng (also master swordsmen) are the parties that Lu Feng is trying to rectify things with. Through cowardly trickery on Chiang's part, a duel ensues and it all winds up with Lu's death. His son is taken to safety by a servant (the man who since raised him). Now with the truth told, Chin Siu Ho seeks out Kuo Choi's aid and seeks vengeance for the wrongful death of his father.