The Possession of Joel Delaney
Tags: violence, murder, flashback

Plot synopsis:
Norah Benson and her younger brother Joel Delaney attend a party being given by Dr. Erika Lorenz. Joel's girlfriend Sherry appears. Norah is extremely protective of her brother, and it is subtly implied that theirs is not an ordinary siblings' relationship. The siblings have sensibly different, albeit somehow complementary mindsets; in contrast to Norah's upscale, self-compliant snobbishness, Joel is more of an adventurous, bohemian type and frequently goes on trips to exotic locations.
Two days after the party, Joel fails to attend a scheduled dinner at Norah's house. When she calls him, all she hears is somebody breathing and making odd sounds into the phone. She tells her children Carrie and Peter to go ahead and eat, and heads over to her brother's seedy Spanish Harlem apartment to find out about his delay. Norah sees Joel dragged out by the police. She then learns that he tried to kill the building superintendent, Mr. Pérez (Aukie Herger), and is being taken to Bellevue Hospital.
She learns that Joel has been taken to the psychiatric ward for observation. At Joel's apartment, she finds the whole place in disarray and an eerie sign painted in the wall of both the super's and his brother's flats. She also finds an unusually large switchblade knife.
Sherry arrives and dismisses the possibility of Joel being homicidal, although she admits to him having a "dark side". At the hospital, Joel claims not to remember the assault on the super. He insists that he did not take drugs but agrees to confess he did in exchange for leaving Bellevue and attending daily appointments with Dr. Lorenz. In one session, Erika asks why someone from such an affluent background would want to live in the East Village. Joel tells her he formed a strong bond with a young Puerto Rican named Tonio Pérez (the super's son, as it is later revealed). At home, Joel behaves oddly. He asks Norah inappropriate questions about her sex life. He sneaks from his room and goes to a nearby nightclub where he finds Sherry intoxicated and flirting with other men. At her luxury high-rise apartment, Joel gets rough during their lovemaking.
The next day is Joel's birthday and he invites Sherry to Norah's for a small party, attended by Norah's kids plus Sherry and Veronica. Joel starts acting childishly, pretending he has found Sherry's lost earring. He then nearly burns Sherry's hair in the candles on the cake and spouts insults in fluent Spanish. Norah goes to Sherry's apartment to return her other earring. To her horror she finds the girl's decapitated body on the bed and her head hanging from a huge plant. Detective Brady arrives to question her, asking whether Joel has any Puerto Rican friends.
It turns out the murder is similar to three others from the summer before in which the victims were found decapitated this way. The grisly deaths got little attention because the girls were Hispanic. The belief is that Tonio Pérez committed the crimes but he's been missing ever since. The investigation stalled when Pérez's neighbors in Spanish Harlem refused to cooperate. The detective insists on seeing Joel, who is taken away by the officer. Norah goes to the library to look at articles about the Pérez murders. She calls home to speak to Veronica but finds out that the maid quit. Norah takes a taxi up to Spanish Harlem and implores Veronica to help her learn what's going on with her brother. Norah is given the name and address of Don Pedro, owner of a store that sells paraphernalia for Santería rituals. He asks her to bring one of Joel's belongings to his flat.
Norah brings a scarf belonging to Joel and finds Tonio's mother, who claims that Tonio is dead and his spirit has entered Joel's body. Mrs. Pérez admits that her son killed the other three girls and tells Norah that Tonio's father killed him when he found out. Others arrive and the ceremony begins. All seem possessed by the spirit they're trying to channel. The ritual turns out to be a failure, though; according to Don Pedro, Tonio's spirit doesn't want to come out because Norah isn't a believer. She must return with Joel.
At home, she finds Joel screaming (again, in perfectly fluent Spanish) and barricaded inside. She takes the kids to Erika's apartment. Erika promises to deal with Joel. Norah rents a car and goes to her beach house. Erika's husband leaves for a business trip, unaware that Joel is standing outside of their apartment building. Norah comes back from the beach with her children and finds Erika's severed head on a cabinet above the refrigerator. Joel is standing nearby with a knife. Now uniformly possessed by his Spanish-speaking persona, he keeps them captive and subjects them to both physical and psychological torment. He taunts them by graphically cutting open a fish the kids caught. Joel puts on music and orders them all to dance.
Joel orders the boy to strip. In the kitchen, he tries to force Carrie to eat dog food before slashing her neck slightly. Benson and the police arrive and Norah yells at them not to shoot. They can only watch what's happening through the glass doors. Norah lunges at Joel to stop him, but he gives his sister a passionate kiss. Norah tells the kids to run out of the house. Joel goes after them and is shot by one of the officers. His sister runs to his side but it's too late. Norah picks up the knife and holds it up toward the cop, now seemingly possessed.