Sinister is a horror film that tells the story of a true-crime writer, Ellison O'Hair (played by James Gunn), who moves his family into a new home with a dark history. The house, located in the suburbs of Brackettville, Texas, was once the site of a horrific mass murder. As Ellison begins to investigate the crime, he discovers a box of disturbing home movies that put him and his family in grave danger.