Ah Ying (Chen Ping) is a former gangster trying to lead an honest life, and occasionally using her fighting skills to help out the girls in the factory where she now works. She befriends young colleagues Chong Lee and Shao Yin-Yin, teaching them self defence because "girls can't be weak anymore". Trouble starts when her old gang finds out where she now works.
This spin-off from the Big Brother Cheng films is definitely more entertaining than its cinematic parents, thanks no doubt to Sun Chung stealing the directing chair from Kuei Chih-Hung. The film makes more of an effort to tell a story than BBC, and suffers much less from the reactionary pro-vigilantism. It seems to think it's a feminist film in fact, with a message of female empowerment... but it's exceedingly hard to take that seriously when the female cast members are required to pop their boobs out at the slightest provocation (and in some cases, for no discernable reason at all).
The action in the films is better than in THE TEAHOUSE or Big Brother Cheng, as I remember them. Chen Ping obviously has nothing like the martial arts pedigree of Chen Kuan-Tai, and Chong Lee and Shao Yin-Yin _certainly_ don't, but brothers Tang Chia and Huang Pei-Chi conspire to choreograph some pretty cool scenes anyway - particularly the finale - plus Wong Chung and Chen Kuan-Tai turn up intermittently to give the girls a hand. Chen's fights are strangely underwhelming though.
The film has it's fair share of flaws - particularly Shao Yin-Yin's overacting (she mugs like a female Fu Sheng) and Chong Lee's... err, underacting I suppose. It manages to survive these problems though, and comes out as a solid and slightly squalid piece of 70's feminisploitation cinema. Definitely the best of the trilogy.