Halloween: The Curse of Michael Myers is the final installment of the Halloween Thorn Trilogy reboot.
On October 30, six years after she was kidnapped from Haddonfield Police Station at the end of the previous film, Jamie Lloyd gives birth to a son, Stephen Lloyd, at an unknown location. Held captive by a cult, Jamie was in fact impregnated by her uncle; serial killer Michael Myers. However, a reluctant midwife named Mary tries to assist Jamie by smuggling her out of the facility with her child. Suddenly, the man in black of the last film appears and impales Mary with a spike on the wall. He then pursues Jamie, killing a trucker who's truck she steals. Jamie briefly hides in a bus shelter before retreating to a nearby barn. Suddenly, Michael appears and throws her onto some farm machinery, killing her. The cult find the truck, but only find a roll of toilet paper wrapped in a baby blanket. Prior to her death, Jamie calls into a radio show discussing Michael Myers.
Dr. Sam Loomis, now retired, overhears her call while reviewing his research on the shadowy character; he has given the figure a name, Conal Cochran. He is visited by an old friend, Dr. Terrence Wynn, who asks him to return to Smith's Grove Sanitarium. Loomis declines but sets out to find Michael.
Also listening to the broadcast in Tommy Doyle. Tommy was a patient of the children's clinic during Jamie's stay six years previously. He now lives across the street from the Myers house, having become obsessed with Michael. He watches as the Strode family, who adopted Jamie's birth mother Laurie, Michael's sister, as a baby, move in. Tommy investigates Jamie's call and locates Stephen in the bus shelter.
The Strode family consists of John Strode, Deborah Strode, their son Tim Strode, his sister Kara Strode and her son Danny Strode. Danny is haunted by visions of Michael. While Tim, Kara and Danny are at school and John goes to work, Loomis arrives at the house and reveals to the naive Deborah the history of her home. She rings John and tries to persuade him to come home, as well as berating him for moving them when he knew of the house's past. She then goes outside and trips. While searching for her glasses, Michael appears with a hatchet and kills her.
That night, while Tommy gets accquainted with Danny and Kara, Tim and his girlfriend Beth attend the local Halloween celebrations. A darkly dressed figure appears but is revealed to be radio host Barry Simms, who was on air when Jamie phoned in. When Beth lets slip that Tim now lives in the Myers house, Barry decides to broadcast live from the killer's former residence. John arrives home and finds Michael waiting in the basement. Michael then stabs him and pushes him onto the fuse box, electrocuting him to death and cutting the house's power. Tim and Beth come to the house ahead of Barry, who is then stabbed to death in his van by Michael. Tim and Beth have sex and Tim goes to take a shower. Michael appears and slits his throat. Kara phones Beth, who she can see through Tommy's telescope, and tells her to leave the house. Suddenly Michael enters the room and stabs Beth to death. Kara then spots Danny crossing the street.
Kara runs after him and is chased through the house by Michael. She escapes by jumping out of a window and then returns to the boarding house that Tommy lives in. There, she meets Dr. Loomis, and the house owner Ms. Blankenship reveals herself to be a member of the Cult of Thorn, who worship the dark god behind Michael's motives. The man in black appears and reveals himself as Wynn, the true Conal Cochran.
Tommy, Loomis, Danny, Kara and Stephen are taken to Smith's Grove, which is where Jamie was held. Michael appears and attacks a surgical team with a surgical machete and then chases the group through the building. Tommy injects Michael with heavy drugs and beats him down with a pipe. Cochran appears and shoots Loomis, who returns fire, mortally wounding Cochran. Suddenly Michael gets back up and decapitates Cochran. Tommy uses ancient rune stones to attack Michael. He then uses a large chunk of Stonehenge to finally defeat the killer for good, who is blasted away by the mystical powers. The film ends as they all drive away in a white van.