Dr. Daniel Challis and Ellie Grimbridge stumble onto a gruesome murder scheme when Ellie’s novelty-salesman father, Harry, is killed while in possession of a strange mask made by the Silver Shamrock mask company. The company’s owner, Conal Cochran, wants to return Halloween to its darker roots using his masks — and his unspeakable scheme would unleash death and destruction across the country.

In 1960, seven pre-teen outcasts fight an evil demon who poses as a child-killing clown. Thirty years later, they reunite to stop the demon once and for all when it returns to their hometown.