In protecting a group of children from bullying and gang violence, the gallant 'Lady Bond' Kong Yin stays with the family of driver Lee Pak in order to give classes in self-defence to Pak's younger brother Calf and neighbours Tak, Ah-ling as well as the young woman Sheung, drilling them in the moves and techniques. Startled by her striking resemblance to his kidnapped girlfriend Tong Ching-yee, Tse Tsi-ming pleads with and convinces Kong to pose as the missing girl to visit her bedridden grandfather Chung-sau. The masterminds behind the abduction, Tong's stepmother and her nephew Chan Chi-biu capture also Tse and the children. Tse brilliantly manages to alert Kong. Fighting and apprehending her opponents, Kong frees the hostages and hands the criminals over to the authorities.

The agile and cerebral fighter Kong Yin is invited to join the police SWAT team. Kong is soon sent on an undercover mission to investigate the gang operating at the Happiness Rubber Plant to coerce female workers into prostitution. An indignant Kong joins hands with fellow worker Chow Mei-ha and factory head Wong Chi-kong to expel Blackie Kei whose ruthless and blatant exploitation of the workers has been going unpunished. Facing the loss of a lucrative source of income, Blackie and his underworld bigwig boss Wu Tin-hung intercept the love letters exchanged between Wong and the wife of the general manager Ting Yuk-lan and use the correspondence to extort money from the adulterers. The fearless Chow dons a maid disguise and ingratiates herself with the gangster, followed by a police raid masterminded by Kong to crack down on the notorious gang.