Q:Build a movie plot around this: Who's murder are Ellie and Challis investigating? Harry
A:
On Saturday, October 23, 1982, shop owner Harry Grimbridge (Al Berry) runs along a barren stretch of road in Northern California. A vehicle containing mysterious figures in business suits is chasing him. Grimbridge is attacked by one of the mysterious figures but escapes. Grimbridge collapses at a gas station clutching a Silver Shamrock jack-o'-lantern mask. He is driven to the hospital by the station attendant Walter Jones (Essex Smith), all the while ranting, "They're going to kill us. They're going to kill us all."At the hospital, Grimbridge is placed in the care of Dr. Dan Challis (Tom Atkins). That night, while Grimbridge sleeps, another mysterious man in a suit enters Grimbridge's hospital room and kills him, then goes to his car and immolates himself.The next morning, Grimbridge's daughter, Ellie (Stacey Nelkin) arrives to identify her father's remains. Ellie and Challis agree to investigate Harry's murder, leading them to the small town of Santa Mira, California, home of the Silver Shamrock Novelties factory. The motel manager (Michael Currie) describes the source of the town's prosperity: irishman Conal Cochran (Dan O'Herlihy) and his factory, which produces wildly popular whole head latex masks for Halloween. While signing the motel register, Challis learns that Ellie's father stayed at the same motel. Other motel guests include shop owners Marge Guttman (Garn Stephens) and Buddy Kupfer (Ralph Strait), Buddy's wife Betty (Jadeen Barbor) and their son Little Buddy (Bradley Schacter). All have business at the factory.Guttman finds a microchip affixed to the back of the Silver Shamrock logo on one Halloween mask. She pokes it with a hair pin, causing an electrical discharge that kills her. Challis and Ellie are awakened by the sound of vehicles and learn of Guttman's accident. Challis attempts to help but is forced away by a group of emotionless men dressed in lab coats.The next morning Challis and Ellie tour the factory with the Kupfers and are alarmed to discover Grimbridge's car there, guarded...