Fong Sum

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.

Wan Cho-sin has two daughters. The elder sister Wai-man is genteel and graceful, and the younger sister Wai-ping, taken under the tutelage of Lady Knight Silver Fox, is extrovert, outgoing and gregarious. The drug kingpin Chung Chi-wang has his eyes set on Wai-man but the girl is in love with Ma Kim-leung. Ko Tin-yam, who fearlessly wields his journalistic pen against the gangster, joins forces with his girlfriend Wai-ping to beat off Kong Yau-ming and the thugs dispatched by Chung. The encounter, leads to Kong's recognition of Wai-ping as his flesh and blood entrusted to Cho-sin's care years ago. Wai-ping pleads with her father to turn over a new leaf but fails to save him from Chung's murderous hand. Wai-man and Ma ingratiate themselves with the gangster, who uses the duo to elude the police while transferring drugs to a secluded villa. Wai-ping tips off the authorities about the traffickers' whereabouts and cracks down on the drug ring.