A group of warriors, led by Chi San Yung (Chiang Sheng) have been picked off one-by-one by a group of men wearing red and black outfits, wearing masks and using the trident as their weapon of choice. The group decides to head for Chang Yi town to meet the respected Lin Yun Chi (Lu Feng). Chi San Yung isn't sure if Lin should be considered a suspect or not.

Meanwhile, listening in on the conversations is inn cook Kao Yao (Philip Kwok), who wants to be left alone yet is harrassed by San Yung's men.

When Lin has drunken so much, he stays at the inn. San Yung asks one of his men to investigate. He is later killed by the Chief of the Masked Killer Gang. Soon, one-by-one, San Yung's cohorts are being killed off by the Masked Killers. Liang Yung (Chu Ko) suspects that Kao may be responsible, but Chen Chung (Chin Siu Ho), who befriends Kao, thinks there is someone else responsible.

Another suspect named by Lin is Fong Su Kwan (Wang Li), who is believed to have bodyguards trained in martial arts. San Yung decides to bring Lin and Fong together in order to see if either of them could be the Chief. However, after another member of San Yung's gang is killed. It turns out there is more than one Chief.

Liang Yung still believes Kao is responsible, but it is true that Kai was once a member of the Gang. He reveals to Chen that the Masked Killers were once hired assassins who now kill for the fun of it and he wanted no part of the gang. He reveals to Chen that #1 Chief in Lin Yun Chi and #3 is Fong Su Kwan. There is a new #2 but has no idea who it is. That is, until Chen fights the Chiefs after Kao decides to leave in order to clear his name.

C hief #2 is none other than Liang Yung. Chen is impaled on a tree by the Chiefs. When Kao finds Chen, he is able to help San Yung prove that his own man, Liang Yung is the #2. When Liang reveals himself, he escapes. San Yung and Kao lead the remaining warriors to the base of the Masked Killers and prepare to end their reign of terror.

The action is fast and furious in this ripoff of well, Five Deadly Venoms. Here, the villains are masked and use tridents to impale their victims. Philip Kwok plays the quiet ex-member of the gang who vows revenge on his former cohorts because of their love of killing. Chiang Sheng plays the young San Yung, whose weapons range from a paper fan to an iron ring. These two in their trademark Venom roles, play the heroes. Lu Feng once again is the villain, but this time, he is one of the villains. Baby Venoms Wang Li and Chu Ko play the other two. Chin Siu Ho is the kind hearted Chen, whose kindness and lack of common sense result in his death in his true fight sequence. The ending is amazing as it combnes booby traps with an all out weapons war. If you liked Five Deadly Venoms, you'll love Masked Avengers.