On October 23, in Northern California, shop owner Harry Grimbridge is chased along a barren road by mysterious men in suits. He makes it to a gas station, clutching a jack-o'-lantern mask. He is driven to the hospital by station attendant Walter Jones. At the hospital, Harry is placed in the care of Dr. Dan Challis, a hardworking physician struggling with the relationships between him and his ex-wife, as well as his children. That night, another man in a suit enters Harry's hospital room, murders him, then Self-immolation. The next day, Dan is confronted in a bar by Harry's daughter, Ellie. He tells her about the strange events of the night before and shows her the mask her father was holding when he was admitted to the hospital. Along with Ellie, Dan traces the mask back to Silver Shamrock Novelties, a company based in the town of Santa Mira, California. The motel manager explains that Conal Cochran and his company, Silver Shamrock Novelties, which produces wildly popular latex jack-o-lantern, witch and skeleton masks for Halloween, are responsible for the town's prosperity. While signing the motel register, Dan learns that Harry stayed at the same motel. Other motel guests include shop owners Marge Guttman and Buddy Kupfer, Buddy's wife, Betty, and their son, Little Buddy, who all have business at the company's factory.