Tommy Lee Wallace's Halloween III: Season Of The Witch is set in the same fictional town as Don Siegel's Invasion Of The Body Snatchers - here's what it means for both movies. Santa Mira, California set the stage for the events of the 1956 classic horror movie, where extraterrestrials have come to Earth to replace humans with identical copies of themselves. In 1982, Silver Shamrock Novelties started mass producing their Halloween masks, which cause the wearer's head to melt with snakes and insects crawling out from within. Based on these two narratives, Santa Mira symbolizes a location where human life is set on a one way path to destruction and, inevitably, dissolves.
Invasion Of The Body Snatchers is one of the most iconic sci-fi horror movies to come out of the 1950s. In 1994, the National Film Registry preserved it for being historically and aesthetically significant. As such, it has been a major source of inspiration for sci-fi horror movies that followed its release. It was even remade in 1978 under the same name, then again in 1993 as Body Snatchers and 2007 as The Invasion. In November 2017, a fourth remake was announced, with David Leslie Johnson-McGoldrick of The Conjuring 2 fame set to write its screenplay. As of this writing, there are no updates on the movie.
John Carpenter's Halloween centered around Michael Myers; Tommy Lee Wallace's Halloween III: Season Of The Witch shifted away from the slasher sub-genre with a more supernatural and sci-fi tone throughout. With Halloween 3's connection to Invasion Of The Body Snatchers, it suggests that the two movies belong in the same universe. The minute details about Wallace's third installment in the Halloween franchise could also propose that the aliens won to some degree and, as a result, they created Silver Shamrock Novelties in order to take over the world, but there are certain elements that create a distinct separation between the two.
If the two movies exist in the same universe, it is important to note that there is a 26 year gap between them. Invasion Of The Body Snatchers has an ambiguous ending where the FBI are called in to handle the invasion, but it does not explain whether it was resolved with a positive outcome. Halloween III: Season Of The Witch's villains are androids that were created by Conal Cochran (Dan O'Herlihy). While this could conclude that the villains of Wallace's movie are not the aliens from Siegel's sci-fi classic, Cochran's origins aren't fully explained, which could suggest he is one of the extraterrestrials that landed in Santa Mira in 1956, and started the Silver Shamrock Company in 1982 as a last-ditch effort to take over.
Cochran could be an alien lifeform, except for the fact that the masks are actually intended to assist in returning to a world where witchcraft and paganism reigns supreme. He explains that he comes from a long line of pagans, but he never truly expands on how he came to the realization that Santa Mira, the androids, and the masks would be the ideal mode to achieve his nefarious goals. This could mean he had help from the aliens, except this is highly unlikely. Instead, it would be more appropriate to theorize that Santa Mira, California resembles Stephen King's Derry or Castle Rock, Maine, where horrors take place without any true explanation for the origins of evil.
Santa Mira, California may just be a hub for evil rather than the aliens from Invasion Of The Body Snatchers influencing Silver Shamrock Novelties from Halloween 3. Had the pagan elements not been included in Wallace's movie, it would be safe to assume that the extraterrestrials did influence Cochran, but that's not the case. Instead, it is more apt to theorize that Santa Mira resembles other evil towns and cities in horror's larger cinematic universe. Invasion Of The Body Snatchers and Halloween III: Season Of The Witch are connected in the same universe under the setting of Santa Mira, but their respective villains have such distinct differences that their connectivity does not extend far beyond the shared location.