After failing to kill stubborn survivor Laurie and taking a bullet or six from former psychiatrist Dr. Sam Loomis, Michael Myers has followed Laurie to the Haddonfield Memorial Hospital, where she’s been admitted for Myers’ attempt on her life. The institution proves to be particularly suited to serial killers, however, as Myers cuts, stabs and slashes his way through hospital staff to reach his favorite victim.

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.

Laurie Strode struggles to come to terms with her brother Micheal’s deadly return to Haddonfield, Illinois; meanwhile, Michael prepares for another reunion with his sister.

The Halloween ban is now lifted in Helen’s Valley, and the sorority girls of Gamma Tau Psi place Michelle in charge of their annual haunted house. Unfortunately for Michelle some uninvited trick or treaters from her past come knocking.