Yiu But-fan marries on the day his father Yan-kit retires as a distinguished swordsman when Yan-kit's nemesis 'Ghostly Mother Blue Flower' Chiu Choi-wan and her foster son Lai Chun-wah gatecrash the party, striking dead the elder and But-fan's wife with the White-bone Soul-thrashing needles. Having pledged his alliance to the anguished son, Taoist Tranquil of Emei vows to eradicate the menace at Mid-Autumn Festival when his junior disciple Kau Suet-mui is challenged to a duel with Chiu. Kau's fellow disciples Hung Tin-bo and Chuk Yuk-heung follow the orders of their master to roam the martial world and tumble into a bandit lair. Extricated from danger by the Taoist, the duo join hands with the passer-by Yiu to thwart Lai's assault on Kau by sorcery, again aided by the Taoist. Yiu, Kau and her peers head back to the Kau Fortress where a martial contest is being held to select a prospective groom for the daughter. Kau overwhelms Lai in the ring but concedes defeat to Chiu.
