Halloween Ends

On Halloween night in 2019, 21-year-old Corey Cunningham babysits a young boy named Jeremy Allen, who pulls a prank on him by locking him inside the attic. Just as Jeremy's parents come home, Corey kicks the door open and accidentally knocks Jeremy over a staircase railing to his death. Corey is arrested for aggravated manslaughter but is cleared by the judge. Nonetheless, Corey is made a pariah by the citizens of Haddonfield, Illinois.
Three years later, Haddonfield is still reeling from the aftermath of Michael Myers's latest killing spree in 2018,[a] while Michael has vanished. Laurie Strode is writing a memoir and living with her granddaughter Allyson. Meanwhile, Corey is working at his stepfather's salvage yard. On his way home one day, he is accosted by high school bullies and injures himself in the process. An observing Laurie brings him to the doctor's office where Allyson works. Allyson and Corey develop a relationship and later attend a Halloween party, where Corey is confronted by Mrs. Allen. Corey leaves the party and runs into the bullies who throw him off a bridge. Unconscious, he is dragged into the sewers, where Michael resides, and is choked by him, but Michael eventually lets him go. As he crawls out, Corey is threatened by a homeless man, and in a struggle, Corey stabs the man to death and flees.
At a dinner date, Allyson’s ex-boyfriend harasses her, leading to Corey later luring him into the sewer to be killed by Michael. Allyson is passed over for a promotion at work, in favor of a nurse who is having an affair with the doctor. Later that night, Corey kills the doctor at his home while Michael kills the nurse. An unknowing Allyson plans to leave Haddonfield with an insistent Corey because of the past trauma, while Laurie realizes Corey is infected by Michael's evil; their different mindsets causes their relationship to fracture. Laurie finds Corey sleeping in the spot where Jeremy died, and offers to help him on the condition that he distance himself from Allyson. Corey retorts by blaming her for the events that have occurred in Haddonfield and says if he cannot have Allyson, no one will.
Corey returns to the sewers where he successfully fights Michael for his mask and embarks on a rampage, murdering the bullies after luring them to the salvage yard, one of whom accidentally kills Corey's stepfather. He goes on to kill his mother, a DJ at a local radio station, who had taunted him earlier, and presumably the radio station's assistant. At the Strode house, Laurie fakes a suicide attempt to lure Corey to her, whom she shoots down the stairs. Corey then stabs himself in the neck to frame Laurie for his death in front of the arriving Allyson, who leaves in distress. Michael suddenly arrives, retrieves his mask, and kills Corey. A fight ensues in Laurie's kitchen, with Laurie managing to pin Michael to the kitchen table and slit his throat, and Allyson, convinced of the truth behind Corey's death after receiving a call from Deputy Frank Hawkins, returns to help Laurie subdue and finally kill Michael by slicing his wrist.
Laurie and Allyson take Michael's body to the salvage yard by police escort, attracting the residents of Haddonfield, who follow them in a procession, and dispose of it in an industrial shredder. In the ensuing days, Allyson and Laurie reconcile, and Allyson leaves Haddonfield while Laurie finishes her memoir and rediscovers her romance with Hawkins.