Like a lot of movies in the found footage horror genre, “The Devil Inside” steeps you in the familiar before ever doing anything to scare you. Dread builds in a mundane atmosphere, all the better for a jump scare out of nowhere. With the threat of supernatural terror hanging just outside what you can see, a viewer is constantly on alert. More significantly, these kinds of found footage mockumentaries are walking a tight line dramatically, suggesting reality with their style but also naturally building to a stark, terrifying conclusion.
Mysteries and abandoned plot threads that may not be the territory of a traditional documentary look sloppy in the context of a narrative film. But “The Devil Inside” never gives up the ghost, and treats its story with an eye for documentary mimicry, even using disclaimers at the outset to claim the Vatican didn’t authorize its production. Off-kilter angles from security cameras are inherently justified, building mood but also functioning as diegetic coverage. One character is the filmmaker behind the camera — like Isabella, he is very invested in the search for answers, but you understand he also is trying to make a movie, especially when he compliments the “great stuff” he got from Isabella’s mother having a demonic breakdown.
In the context of her dramatic search for answers, we are given an inside look at an exorcism school in Rome, that combination of religion and science. One student has even studied medicine. Some students are skeptical of the idea of exorcism and possession, in debates that dig into the eternal search for explanations of inexplicable behavior. Of course, this is a horror movie, so we know where that’s going.