As far as found-footage/faux-doc horror goes, this one isn't bad, if only because most of the truly scary stuff happens in the fascinating real-life catacombs beneath the streets of Paris that house the skeletal remains of millions of dead folks, seemingly waiting to have a horror movie made in their midst. Director John Erick Dowdle (who co-wrote the film with brother Drew; the pair also made DEVIL, QUARANTINE, and the notorious THE POUGHKEEPSIE TAPES) uses the decidedly claustrophobic space to great advantage in building the scares, by taking full advantage of the vast shadows, tunnels leading to nowhere, and a soundscape that will have you peeing in your britches.
AS ABOVE/SO BELOW begins in Iran where Scarlett (Perdita Weeks, THE INVISIBLE WOMAN), a young university researcher, is on a quest to continue the work her now-dead father started, to discover a missing artifact that is the key to translating an ancient text that will lead to her a stone that legend says has a degree of power in the world of alchemy. Scarlett soon arrives in Paris where George (Ben Feldman, CLOVERFIELD and "Mad Men"), the only man she knows who can translate the text, is living. Before long, they are hiring a local team of French "explorers" to take them into the off-limits areas of the catacombs to find a mysterious hidden room under the Paris streets.
AS ABOVE/SO BELOW really picks up steam when the team is forced to take a passageway that even the guides refuse to enter, simply because the accepted feeling is that it's evil. Some may balk at the idea that nearly everyone on the team has a pin camera on their mining helmet, so not only can multiple angles be achieved, but the lighting is often quite wonderful, unless of course, things need to be dark. I have no idea if this film was actually shot in the catacombs as much as it appears, and honestly, it doesn't matter because the look and feel of these sets/locations is absolutely believable, and it won't take long for audience members to start seeing, smelling, experiencing what this team is.
As the group gets closer to its objective, we begin to realize that we actually don't know what Scarlett hopes she's going to find once she gets wherever "there" is. Because based on all the clues they've decoded to get to this point, it seems she could be accidentally leading them to a gateway to hell. And the way the group exits the miles of tunnel is even cooler and freakier than the way they came in. Things lurk and make terrifying noises and even sometimes chase our heroes through the catacombs.
AS ABOVE/SO BELOW has a plotting similar to a NATIONAL TREASURE film—no matter what clues they are given, someone on their team has the necessary education to figure out what the next move is. That combined with the fact that nearly everyone has a damn camera in their helmet makes accepting this story at face value a bit of a leap of faith. Still, this one has something special about it, and I was genuinely creeped out for a good deal of the movie, despite the fact that the leads both fall into that sad and awful horror trope in which a small group of very smart people do very dumb things with an alarming frequency. If you can live with that, you might enjoy this surprising slice of scary movie.