Plot

A controversial true-crime writer finds a box of Super 8 home movies in his new home, revealing that the murder case he is currently researching could be the work of an unknown serial killer whose legacy dates back to the 1960s.

Crime writer Ellison Oswalt moves his family into a house where a horrific crime took place earlier, but his family doesn't know. He begins researching the crime in hopes of writing a book about it. Oswalt examines video footage that he finds in the house to help him in his research, but he soon discovers more than he bargained for.—Michael Hallows Eve

True crime writer Ellison Oswalt has moved his family - wife Tracy, twelve year old son Trevor, and adolescent daughter Ashley - to a small town in Pennsylvania so that he can be close to the source information for his latest book. Trevor has in the past suffered from night terrors which only increases with this move. Their arrival does not sit well with the county Sheriff as Ellison's reputation for placing the work of law enforcement in the cases covered in his previous books in a bad light precedes him. The Deputy Sheriff, a fan, sees Ellison in a different vein, he drawn to the possible fame in secretly helping Ellison with his research. Outwardly, the case is of a missing adolescent girl, Stephanie Stevenson. What Ellison has not told Tracy or the kids is that Stephanie is only the tip of the iceberg, as the case also involves the murders of Stephanie's immediate family members by hanging in their back yard, and that the Stevenson home is the one into which they have just moved. In the attic of the house, Ellison discovers a box of Super 8 home movies and supporting equipment, that find which he believes is just the start of what could be career defining research which does include information into the Stevenson murders and the possible involvement of occultist forces. As Ellison receives aid in his research from the Deputy, from Professor Jonas at the local college he who specializes in the occult, and as he himself pieces together more and more information from the Super 8 movies, there may be a line at which he crosses before it is too late for the safety of himself and his family from what is going on.—Huggo

Professional true crime author Ellison Oswalt, father of cool teen Trevor (12) and adolescent Ashley, moved his family once more, to a Pennsylvanian small town, without telling his ingrate wife Tracy it's to research his next book, their new home being the central site of the mysterious crimes from the plot, relating to the open case of missing local adolescent Stephanie Stevenson. The sheriff clearly would prefer him to leave, but his deputy, a fan, offers research help. It becomes scarily real when among spooky events or coincidences, Trevor gets a new series of terrifying nightmares and Ellison stumbles in the attic upon a box of Super 8 home movies and supporting equipment, evidence of the horrible Stevenson slaughter without rational logic. For strange references, he consults Jonas, a local college professor specialized in the occult. Oddities continue, even when he tries to dispose of the movies.—KGF Vissers

Desperate to find inspiration for a new bestseller that will put him on the map, true crime author Ellison Oswalt moves his family to rural Pennsylvania. As he delves into an unsolved murder case that shook the community years ago, a dusty box in the attic filled with amateur home movies captured on Super-8 film piques Ellison's curiosity to dig deeper. But in this case, ignorance is bliss. As endless hours of raw footage brimming with atrocious acts of torture make the writer lose his nerve, Ellison must decide: Should he cash in on the disturbing discovery for the sake of success or stop before he loses his sanity and soul forever?—Nick Riganas

The film opens with Super 8 footage depicting a family of four standing beneath a tree with hoods over their heads and nooses around their necks. An unseen figure saws through a limb acting as a counterweight, causing them all to be hanged.

Months later, washed-up true crime writer Ellison Oswalt (Ethan Hawke) moves into the murdered family's home with his wife, Tracy (Juliet Rylance), and their two children Ashley (Clare Foley)-- a gifted artist who is allowed to paint on her walls-- and Trevor (Michael Hall D'Addario), who begins re-experiencing bizarre night terrors upon moving into the home. Only Ellison is aware that the house they are moving into was the crime scene. Ellison intends to use the murders as the basis for his new book, and hopes that his research will turn up the fate of the family's fifth member, a little girl named Stephanie who disappeared following the murders.

Ellison finds a box in the attic, which contains a projector and several reels of Standard 8 mm footage that are each labeled as if innocent home movies. Watching the films, Ellison discovers that they are snuff movies depicting families being murdered in various ways, including having their throats slit in bed (Sleepy Time '98), being burnt to death in a car (BBQ '79), being drowned in their pool (Pool Party '66), being run over by a lawn mower (Lawn Work '86) and the hanging that opened the movie (Family Hanging Out '11).

The drowning film proves especially disturbing for Ellison after he notices a demonic figure watching the drownings from the bottom of the pool before turning to look at the camera. Ellison eventually finds the figure observing the murders in each of the films, along with a strange painted symbol; inspecting the underside of the lid of the box containing the films, Ellison discovers numerous crude drawings depicting the murders, along with crude drawings of the demonic figure, identified as "Mr. Boogie."

Consulting a local deputy (James Ransone), Ellison discovers that the murders depicted in the films took place at different times, beginning in the 1960s, and in different cities across the country. He also learns that the families were all drugged before being killed; and that a child from each family went missing following every murder. The deputy refers Ellison to a local professor, Jonas (Vincent D'Onofrio), whose expertise is the occult and demonic phenomena, to decipher the symbol in the films. Jonas tells Ellison that the symbols are that of a pagan deity named Bughuul, who would kill entire families so that he could take their children into his realm and consume their souls.

One night, Ellison hears the film projector running and goes up to the attic. There, he finds the missing children in various states of decay, watching one of the films. Bughuul suddenly appears on camera before physically appearing before Ellison. Ellison takes the camera and the films to the backyard and burns them. Then he wakes his family to tell them that they are moving back to their old house.

At his old home, Ellison receives a message from Professor Jonas, who sends him scans of historical drawings associated with Bughuul; each had been partially destroyed because ancient cultures believed that Bughuul lived within the images, and that they acted as portals between his realm and the mortal world. Ellison then discovers the projector and films in his attic, along with a new envelope of film labeled "extended endings." During this time, the deputy tries calling several times, but Ellison never answers.

The next time the deputy calls, while Ellison is assembling the films, he answers. The deputy informs him that he has discovered a link between each of the murders: Every family had previously lived in the house where the last murder took place, and each new murder occurred shortly after the family moved into their new residence. By moving back to his old home after living at the site of the previous murders, Ellison has placed himself and his family in line to be the next victims.

Ellison then watches the footage. He finds that it depicts the missing children coming onscreen following each murder, revealing themselves to be the killers before suddenly disappearing. Before he can react, Ellison becomes light-headed; inspecting his coffee cup, he finds a note reading "Good Night Daddy" and a green liquid inside the cup before losing consciousness.

Ellison awakens to find himself, his wife and his son bound and gagged. Ashley approaches holding the 8 mm camera, and promises him that she will make him famous again. Ashley then proceeds to murder her family with an axe, using their blood to paint images of cats, dogs, and unicorns on the walls. Her work complete, Ashley adds a new drawing to the box lid, complete with the drawing of "Mr. Boogie." She views the Super-8 film of her murders, which concludes with an image of the missing children watching her. Bughuul appears, green blood covering his hands, causing the children to flee. He lifts Ashley into his arms and disappears into the film with her.

The film concludes with an image of the box of films in the Oswalt family's attic, now accompanied by a reel labeled "House Painting '12". Bughuul suddenly appears, warning that the viewers are next.