Sinister is a horror movie about a writer (Ethan Hawke) who wrote one bestselling true crime book, and has spent the rest of his adult life chasing the fame he once had. Ellison has carted his long-suffering family with him from crime scene to crime scene, trying to find another murder story that will make the public care about him again. And as the movie begins, he thinks he's gotten his big break. After moving his family into the house where another family was recently killed under bizarre circumstances, he's discovered a treasure trove of old Super 8 movies in the attic. All of them feature horrific family murders. But that's actually the least interesting part of the movie, though it is probably the scariest. The best part is something you'd never anticipate.
Very light spoilers ahead.
There are a lot of things that Sinister writer Robert Cargill and director Scott Derrickson got right about making a good horror movie. First of all, they invented a new monster, the Babylonian deity Bagul (yes, I could hear people in the theater around me making Ghostbusters jokes about Zuul), who starts out looking sort of like the Wicked Witch of the East and winds up looking legitimately disturbing. More importantly, they also came up with a convincing reason why Ellison doesn't go to the cops as soon as he discovers the snuff movies in his attic. That's right — this is a horror movie that uses character development to justify actions that most horror movies never explain. (For example: "Why does he go up the stairs instead of calling the police?" etc.)
Ellison has a rough relationship with the police, because his bestselling true crime book was about how the police bungled the search for a killer. In the course of his research, Ellison managed to find the true killer, becoming both a hero and a famous writer in one stroke. But in a subsequent book, Ellison tried to do the same thing and it all went south. His book actually got the wrong person sent to prison, and let a killer run free. So cops aren't exactly crazy about Ellison — nor is he crazy about them. But more importantly, the formula for all his books is "I found the evidence that detectives didn't see." So when he finds a treasure trove of snuff movies, his first thought is that now he's got that next bestseller, especially if the police don't get involved.
In other words, Ellison is just the kind of stupid, selfish bastard who deserves to be tormented by a Babylonian monster.
Unfortunately, the first two-thirds of the movie feel like they're unfolding in real time, which is to say extremely slowly. We sit with the increasingly jerkwaddish and drunk Ellison as he watches every single snuff movie multiple times, gradually discovering what they have in common. The problem is that showing us new scary shit is not the same thing as moving the plot along.
But then, just when you are about to give up from a combination of jump-scare induced dysphoria and boredom, the movie kicks into high gear. Suddenly, Ellison starts interacting with people who aren't on iChat. James Ransone is hilarious as the deputy (and Ellison fanboy) who agrees to help the writer crack the murder case that happened in his own house. He pretty much steals the movie every time he walks on screen. And we also start to see more clearly how terribly Ellison has been treating his kids — neglecting them, responding with indifference when they do nice things for him, and even moving into a crime scene when his son is prone to night terrors (which are made much worse after the kid finds out about the murders).
In the final act, the movie goes from being a combination of jump scares and an edging-on-irritating character portrait of a fame whore, to being something that is extremely creepy and deeply satisfying. The ending is fucking amazing — and how often can you say that about a horror movie? Usually the end of a horror movie is reserved for last-minute, improbable monster slaying or recitations of Babylonian warding spells, or some lame-ass moment where the characters realize that all they have to do is believe in love or something. But Sinister does none of that. It surprises you, and in the process allows you to see the movie from a new perspective.
I'm not going to spoil the movie by telling you exactly what that "new perspective" is — I suspect there will be a lot of disagreements over it. The good news is that you won't feel cheated.