Hereditary(2018)

Pooper:
Annie’s mother was part of a sect of worshippers of the demon Paimon. Charlie was actually Paimon, but Paimon needed a male’s body. The sect (of which Joanie was a member) succeeds in transferring Paimon/Charlie’s soul into Peter’s body (which they succeed in doing at the end). Annie appears to have subconsciously assisted the cult (inheriting her mother’s devotion to Paimon).

Long Ending:
Annie’s (Toni Collette) mother, an abusive woman with mental illness, passes away before the film opens. Her husband Steve (Gabriel Byrne) and teenage son Peter (Alex Wolff) seem nonplussed. But Annie’s 13-year old daughter Charlie (Millie Shapiro) is devastated as the only one in the family particularly close to her grandma. Charlie seems very troubled, having a perpetual scowl on her face and decapitating dead animals. Annie is surprised when many people she never met turn up at her mother’s funeral. Soon after the funeral, Steve learns from the cemetery that the grandmother’s gravesite has been desecrated, but keeps this from his family.

Annie eventually starts going to group grief counseling. There, she discusses her tragic upbringing. Both her parents suffered from mental disease and her father eventually committed suicide via starvation. Her brother also committed suicide, saying in his suicide letter that their mother kept “putting other people inside of him.” Although Annie cut off contact with her mother for years, they eventually reconnected when Charlie was born. Annie essentially let her mother handle the child rearing duties for Charlie as a baby (i.e., feeding her, staying up with her, etc.). Annie also appears to have some issues. One night, while sleepwalking, she doused herself and the two kids in paint thinner and lit a match (she was woken up before she could ignite them all). At the group therapy, Annie befriends an older woman named Joanie (Ann Dowd).

Annie forces Peter to bring Charlie with him to a high school party. Peter goes to get high while Charlie begins eating the party food. Charlie’s throat begins closing as she eats something exposed to peanuts (she has a peanut allergy). Peter tries to race her to the hospital as Charlie sticks her head out of the window to try and breathe. Peter swerves to avoid an animal carcass in the road and as a result, Charlie is decapitated when her head strikes a telephone pole.

The family is utterly devastated to lose Charlie and begin to unravel. Annie and Peter begin seeing ghostly visions. Annie admits that she never wanted to have Peter due to her mother pressuring her to have a son. Steve and Annie stop sleeping in the same bed. Annie essentially blames Peter for Charlie’s death (and he questions why she made him take Charlie to the party in the first place).

Joanie invites Annie over and shows her a ritual whereby she is able to conjure dead spirits (who then is able to move objects). Joanie gives Annie instructions and materials to reach out to Charlie. Annie gets her husband and son to participate in a summoning ritual, although it is much more volatile than at Joanie’s house. After the ritual, Annie’s behavior becomes even more erratic and Peter becomes possessed in class, violently bashing his head into a desk and knocking himself out (Steven brings him to recuperate at home). Annie goes through her mother’s belongings and discovers her mother was the head of a sect that worshipped the demon Paimon. The group believed that Paimon needs to inhabit a male’s body (pictures also show that Joanie is a member of the sect). Essentially, Charlie was Paimon and the sect has been taking action to have Charlie/Paimon inhabit Peter’s body. Things reach a head when Annie and Steve find the grandmother’s corpse smuggled into their attic with demonic symbols having been painted throughout.

Annie tries to stop things by throwing the sketchbook she used to establish a link with Charlie’s spirit into the fire, but this causes Steve to also burst into flames. Before she can put him out, Annie herself is possessed.

Peter finally awakens and finds his father’s burnt corpse in the living room. He is then attacked by his possessed mother and is chased into the attic. Up there, he finds several of the sect worshippers and witnesses his possessed mother saw off her own head. Panicking, Peter jumps out of the attic to his apparent death. A light (Charlie/Paimon’s soul) lands on and inhabits Peter’s body. Peter/Paimon arises and is greeted by all the sect’s followers. He is led to a shrine (where Charlie’s severed head bears a crown and both Annie and her mother’s corpses are laid in a bowing position). The crown is removed from Charlie’s head and placed atop Peter.

The idea is that the mother’s evil was hereditary. Her struggles could be viewed as nature vs. nurture. Annie took many subconscious actions that furthered the sect’s goals, i.e., her nature (letting her mom raise Charlie, refusing to look through her mom’s belongings until it was too late, ignoring obvious signs that Joanie was linked to her mom, possibly storing the grandmother’s body in the attic, having Peter take Charlie to the party). But she also took subconscious and conscious actions to attempt to stop the sect, i.e., nurture (attempting to have a miscarriage when pregnant with Peter, attempting to light the children on fire, burning the sketchbook linking Charlie to her family).