The crime syndicate demands that Cheng Chung-bo lead the way to the treasure trove, holding his family hostage. Booby-trapped, Cheng Fai disengages the device and flees to join Flying Heroine Ma Chau-wan and Detective Wong. Meanwhile, the ingenious scientist Dr Ng is enlisted by the ringleader Ho Kei-ming to match wits and brawn with Fai and Ma. Ma slyly earns the trust of a bewitched Ng, claiming to be Fai's biggest foe. Ng ushers Ma into the headquarters where he meets his doom. With his patience running out, Ho grasps an apprehended Chung-bo on a treasure hunt while the pursuers are diverted from their course. Ma recognises her long-lost father from among the gangsters and brings him to his senses with words of absolution. The father pledges his alliance to the duo in crushing the gang and saving Chung-bo and wife.