Towards the end of the Shaw Brothers' rein over kung fu cinema, the studio branched out into other genres, enjoying some success in the supernatural horror market. Much of their horror output was typified by black magic storylines with gross-out special effects, Bewitched being one of the best examples.
The film opens with the discovery of the decomposed body of a little girl, a nine-inch spike having been hammered into her skull. A police investigation leads to the arrest of her father, Stephen Lam Wai (Fei Ai) who admits to the murder, but claims that he was under the influence of a spell. Sentenced to death by hanging, the man tells his story to policeman Bobby Wong King-Sun (Melvin Wong), and begs the cop to find out what drove him to kill.
According to Lam Wai, the trouble began when he wooed a pretty young woman, Bon Brown (Lily Chan), while on holiday in Thailand. After several days of being romanced by Stephen, Bon gave her new beau an amulet and made him swear to return to her by June 30th. When Stephen returned home to Hong Kong, he boasted about his holiday romance to his work colleagues (no doubt telling them about Bon's topless sprint across the beach, which is shown in slow-motion), but neglected to keep his promise to return. That's when the crazy stuff started to happen: the amulet caused a large stain on his chest, which sprouted hair, he became impotent, and his daughter began to act very strangely indeed. An old woman told him that he had been possessed and that the person closest to him would try to kill him and the only way to stop them would be to hammer a large nail into their head.
Bobby doesn't believe a word of the killer's crazy story, until he too experiences a scary supernatural phenomenon. Now convinced, he travels to Thailand to investigate, learns that Bon had a spell put on Stephen (the magic involving oil extracted from the corpse of a pregnant woman), and attempts to remove the curse with the aid of an old witch (who performs a ritual with some bad flute playing, a levitating skull, a twig and what looks like a small Wade figurine of a frog). When this fails, he visits a monk, who enters into a supernatural battle with the wizard who cast the spell. Cue lots of yuckiness, including the villain drinking blood from a vat full of dead babies, his face oozing pus, and a nail slowly pushed through the palm of his hand.
Unfortunately, the monk is unable to defeat the powerful wizard, and needs a week to recover before he can try again. During these seven days, Bobby is subjected to a variety of spells cast by the miffed magician, which leads to more madness, including the cop developing an appetite for raw pork liver, a bout of heart trouble caused by a lemon, Bobby's wife being stabbed by a flying knife, and a guy getting dragged under a moving car. Director Chih-Hung Kuei also sees fit to throw in those mainstays of the genre, maggot eating and worm vomiting. Meanwhile, Bobby also has to contend with an escaped lunatic who is causing havoc, having got his hands on a cop's gun (in the film's most shocking moment, the madman shoots a child several times in the chest).
The entertaining ending sees the return of the monk, refreshed and ready for round two, in which he successfully desiccates the wizard, forcing a bat demon to fly out of his mouth!
