Odd things are happening to hairdresser May and her fiance Bon, which trace back to a holiday Bon took in Thailand with his three friends - Kong (May's brother), Nam and Kent. They are caught in a battle between wizard Laimi and an evil wizard and her husband, after which the tourists stay at Laimi's place for a few days, where they meet his lovely sister. The sister is bored and fancies Bon, and she asks Laimi to put a love hex on him.
But the hex is applied to the three other guys by mistake. Under the spell, the guys share a night of lust with the sister, who imagines it's Bon alone who is with her. In the confusion after the spell lifts, the sister manages to impale herself on a knife. The guys hotfoot it back to HK, but the good Laimi turns bad and sets on a path of revenge. As his evil grows, so does his desire to possess May. Also in this wild romp is a Thai witch Mei, who may have the power to stop Laimi, and Yuen King Tan repeats her lecture on giving great blowjobs that she did in Naked Killer Two.