The Sinister trailer uses text cards and voiceovers to set up the plot of a true crime writer who moves his family into a house where a horrific crime occurred. As he researches the crime, he finds disturbing snuff films in the attic that show more than he bargained for. The trailer builds a sense of unease through unsettling music, shaky camerawork, and glimpses of a mysterious figure. Through crosscutting between the family's deteriorating situation and clips from the snuff films, the trailer hints at a dark threat pursuing the family.