Halloween III: Season of the Witch is a 1982 American science fiction horror film and the third installment in the Halloween film series. It is the first film to be written and directed by Tommy Lee Wallace. John Carpenter and Debra Hill, the creators of Halloween and Halloween II, return as producers. Halloween III is the only entry in the series that does not feature the series antagonist, Michael Myers. After the film's disappointing reception and box office performance, Michael Myers was brought back six years later in Halloween 4: The Return of Michael Myers (1988).
It treats the prior films in the franchise as fictional films, and the film's tagline is a reference to the one from the original as well. It also departs from the slasher genre, which the rest of the installments were a part of, and instead features a "witchcraft" theme with science fiction aspects. John Carpenter and Debra Hill believed that the Halloween series had the potential to be an anthology series of films that centered around the night of Halloween, with each sequel containing its own characters, setting, and storyline. Director Wallace stated that there were many ideas for Halloween-themed films, some of which could have potentially created any number of their own sequels, and that Season of the Witch was meant to be the first.
The frequency of graphic violence and blood is less than that of Halloween II. As with other films in the series, suspense and tension is a key theme, and the element of violence against young children is also explored. On a budget of $2.5 million, Halloween III made a profit by grossing $14.4 million at the box office in the US, but it was also the poorest performing film in the Halloween series at the time. Most critics gave the film negative reviews. Despite the reception, re-evaluation in later years has given Halloween III new legions of fans and has established its own reputation as a stand-alone cult film.
On October 23, in Northern California, shop owner Harry Grimbridge is pursued by mysterious men in suits. After nearly being killed by one man who is crushed to death, he flees, clutching a jack-o-lantern Halloween mask and collapses at the shop of Walter Jones, who calls for help. Harry is placed in the care of Dr. Daniel Challis, an alcoholic doctor who has a strained relationship with his ex-wife and two children. Later that night, Harry is murdered by another man in a suit, and the man immolates himself inside his car when Daniel attempts to pursue him.
Harry's daughter, Ellie Grimbridge, meets Daniel at a bar. She reveals that she discovered suspicious events surrounding Harry's death, which leads the two to travel to the Silver Shamrock factory in Santa Mira, California, where the Halloween masks are produced, to investigate. Upon arrival, they check into a motel where they meet others with business at the factory, including Buddy Kupfer and his wife and son, and Marge Guttman, a disgruntled customer. The motel manager reveals that Conal Cochran and his factory, Silver Shamrock Novelties, which produces the popular Halloween masks, are the source of the town's prosperity. While checking in, Daniel learns that Harry was also a recent guest of the motel.
A local vagrant tells Daniel about Cochran and spouts plans to burn the factory down, and is later decapitated by the men in suits. Marge discovers a microchip on the back of the medallion of one of the masks, and as she curiously picks at it with a hairpin, the medallion emits a laser which fires into her face, leaving her face horribly mutilated. Marge writhes in agony as an insect crawls out of her mouth. The next morning, men in lab coats take Marge's body away in a Silver Shamrock van. Daniel overhears the motel manager telling Cochran that it was a "misfire".
Daniel and Ellie tour the factory with the Kupfers, and Ellie discovers her father's car, guarded by more men in suits. They decide to flee and contact the authorities, but Daniel cannot reach anyone outside of town by phone, and Ellie is kidnapped and taken to the factory. Daniel proceeds to the factory, where he is assaulted by one of the men in suits, who are revealed to be androids created by Cochran. Meanwhile, a pathologist investigating the car fire is murdered by one of the androids when she learns the truth and attempts to contact the police.
Daniel is captured by Cochran and his men. Cochran reveals his plan: the microchips on each mask contains a fragment of Stonehenge. Upon viewing the "Big Giveaway" commercial, the microchips will activate, killing the wearer with fatal brain damage and causing a swarm of insects and snakes to emanate from their bodies, also killing anyone nearby. Cochran demonstrates this by killing the Kupfers this way. Cochran locks Daniel in a room with a mask on to kill him as well, and explains he intends to resurrect ancient pagan rituals of sacrifice during the age of witchcraft from his native Celtic lands. Daniel is able to escape his bonds, flee through a ventilation duct and contact his ex-wife to convince her to get rid of the childrens' masks, but she dismisses him as being drunk.
After rescuing Ellie, Daniel sneaks into the control room, activates the commercials and pours a box of the medallions from a ceiling rafter, killing everyone. Cochran himself is killed by the Stonehenge rune, leading to a massive fire that destroys the factory. As they flee, Daniel is attacked by Ellie, who is revealed to be an android duplicate, and Daniel crashes his car. He destroys the duplicate Ellie with a tire iron and flees on foot to Walter's shop, where he frantically calls the various television networks, convincing all but one to stop the broadcast. Nationwide, millions of children (all wearing Silver Shamrock masks) switch over to the only network that is still operating. As the commercial begins to air, Daniel repeatedly and helplessly screams "STOP IT!" into the telephone as the screen cuts to black.