Plot summary

Sinister 2, instead of using super 8 film the way the first Sinister movie did, uses other found footage mediums such as vinyl records, a ham radio and 16mm film. The film begins with a 16mm home movie of three people tied to crosses in a rural cornfield. One of the crosses suddenly catches fire, killing the person tied down to it.Deputy So & So from the first Sinister film visits a Catholic confession booth, and it is revealed to the audience that he is no longer a deputy because of his involvement with the Oswalt case. He is now a private investigator, and he spends his free time burning down the houses which he thinks that Bughuul visited. Meanwhile Courtney, a mother of two twin boys (Dylan and Zach), is shopping at the supermarket when suddenly a pervert begins following her, hired by her abusive ex-husband to locate his family. The pervert almost catches her, but she escapes with her sons and he is stopped by a security guard. She drives out to a decaying farmhouse where she and her sons have been in hiding for some time. Dylan has been having nightmares, and to stop them, his not-so-imaginary friend Milo (one of Bughuul's victims), shows him a number of 16mm snuff reels depicting families being murdered in various ways. One film shows a family eaten by alligators (Fishing Trip), one shows a family frozen to death in the snow (Christmas Morning), one shows a family being electrocuted violently (Kitchen Remodeling) and one shows a family being disemboweled by rats in a church (Sunday School). Zach becomes increasingly violent, calling his mom and brother nasty names, beating up his brother cruelly and displaying behavior akin to his abusive dad.Deputy comes to the house to burn it down, assuming that it is empty, but he's stopped by Courtney who threatens him and tries to chase him away. When she realizes that it's all a big misunderstanding, she invites him in for coffee. He explains that ever since his best friend Ellison Oswalt, was murdered, that he's been investigating similar cold cases. Courtney allows him to investigate the nearby church, where the rat murder happened, and while investigating, Deputy witnesses a number of odd and frightening paranormal things. Clint shows up without warning, along with a team of cops, demanding that the boys come out to see him, but Deputy chases them away, with the threat of telling the media about Clint's abuse. It is also revealed that Deputy was nearly arrested for the Oswalt family's murder but that the charges were dropped. Courtney invites him for supper and sees how nice he is to her and the boys, so she lets him spend the night on the living room couch before driving back to his motel. He wakes up in the night and goes over some crime scene photos, and Courtney comes downstairs. They start drinking out on the porch and she tells him about Clint. Deputy tells her that her abused son reminds him of himself when he was a kid (implying that he was abused by his own father in the past). He also tells her about his motives for obsessing with the Oswalt murders. Courtney tells him that she wishes he was the boys' father, and when they go back inside, they kiss briefly.The next morning, Deputy drives away to visit Dr. Stromberg, who reveals that Professor Jonas (from the first Sinister film) has gone missing, and that he discovered a disturbing recording on a HAM radio of a child speaking in Norwegian and then killing their family. The words translate back to "I can't hear Bughuul over your yelling, mom!" in English. The deputy requests that the radio be destroyed and it's revealed that Bughuul travels through art (books, film, music, drawings).At the same time, Courtney and her sons are taken from the house by Clint, and Zach watches the last film, Dental Work (a man having all his teeth pulled without anesthesia). Deputy shows up to rescue them, but Clint beats him up and threatens to murder him, so he leaves, and Clint starts the abuse all over again. The next day, Dylan texts Deputy with the words "Help us!" Zach becomes possessed and starts filming his family with the 16mm camera, drugging them, tying them to crosses and then lighting one cross on fire, with Clint on it. Clint is killed and he twitches violently in the flames, but before Zach can finish off his family, Deputy knocks him down with his car and unties Courtney and Dylan. Zach picks up the camera and a scythe and starts chasing them all through the cornfield, partially cutting off Deputy's hand, but they all make it back to the farmhouse. Zach searches for his family but Deputy hides them both, and Milo and the other dead children begin destroying the house room by room. They crush Deputy behind a desk and hit him with golf clubs, but before Zach can finish off Courtney and Dylan, Deputy smashes the camera, exposing the film to the light and destroying it instantly. Zach screams "NO!" repeatedly and runs to the basement, only to be cornered by the dead kids, who all worriedly tell him that Bughuul will get rid of their souls now. They disappear and Bughuul touches Zach's shoulder, turning him into ashes and killing him.Deputy, Courtney and Dylan drive away, back to Deputy's motel, but when he goes inside, he finds the HAM radio sitting on the nightstand. The voices of dead kids start drifting from the speakers, chanting "It's the kids! It's the kids! It's the kids! ...DEPUTY!!!" Bughuul's face suddenly pops up and it's implied that Deputy is killed.