Michael Myers is dead. 
He died when Laurie Strode shot him in the head on that first Halloween night.
One year later, Laurie is still reeling and dealing from those events. Her damaged psyche is trying to repair itself while haunted by the fact that Michael is still out there since his body went missing (stolen by raging relatives of the victims, townsfolk that mutilated his corpse). She then loses herself when Samuel Loomis releases his new book and its revealed that Laurie isn’t Laurie, but Angel Myers. In her mind, Laurie is killed by Michael (Mya, her innocence, and Harley, her desire/experience) and she transforms into Angel, who kills her best friend, Annie, and Loomis. Angel then kills Michael in her mind, to usurp her fears and take on the mantle of the family name. She walks out of that inner core of her psyche, the tattered barn, for all to see. She has reached the end of her therapy to face the reality of what she’s done.
After a few years in a mental asylum, Angel Myers feigns sanity and proceeds to act as a repaired Laurie Strode. She proceeds to capitalize on her ordeal by using the media to blow up her story for all to know. She pretends to be Innocent and humble Laurie but clearly has a mission. She gets close to a man, a love interest, who is a reporter.
Suddenly, there are people being murdered around them. Some people suspect Laurie is relapsing; others are theorizing that Michael Myers was never dead and is actually back this time.
We eventually find out that Angel is killing, alongside a vision of her brother, those that get too close to the truth; her truth.
Angel is searching for something and using people along with media coverage to get what she wants.
When her new love interest/ reporter friend discovers that its her doing the killing, she knocks him out and subdues him.
Angel has the info she needs and proceeds to her target.
Angel finds what she’s been looking for on a much publicized meeting/interview, on Halloween night, where she finally meets her real biological father. There’s an emotional televised meeting between them. The father is clearly faking a want to love and accept her back into his life. “Laurie”/Angel coyly accepts.
Angel is introduced to his new family and pretends to like them.
Later she holds the family hostage in order to get the truth she’s been seeking from her father. As she does this, her boyfriend goes after her.
Angel tells her father that she wants him to experience what he did to her and the family he abandoned.
Her boyfriend manages to free the family while trying to stop her, but she gets away and hunts the family, killing them one by one alongside her imaginary brother.
She proceeds to slaughter them all.
Her boyfriend tries to stop her, but she kills him meticulously and carefully as he gets near her.
Angel slowly kills her father, taking turns torturing him with Michael. Her father then gets the upper hand when the televised media arrives to see him holding a knife to her throat, maintaining the innocent image of Laurie.
Her father slits her throat on live television.
It is revealed that Angel set it up for all evidence to point to framing her father as the killer of all the murders.
The image of Laurie Strode, the innocent and damaged victim of this man, her estranged father, lives on while her father gets the Myers family retribution.