The plot is pretty straightforward: an intrepid archaeologist finds a code that leads to the location of the legendary Philosopher's Stone, which is somewhere in the catacombs of Paris. What happens next is a found-footage adventure that's produced well enough to have more creative direction than The Blair Witch Project (1999) - no frustrated university students throwing maps in the river as the camera shakes here - while still having a realistic touch.
The actors in the film play their parts well, coming across as relatively realistic characters despite falling into a few stereotypes--the main character may be a little too Lara Croft-esque to be believable (multiple IMDb reviews compare the film to Tomb Raider), and how many people do you actually know who casually break into churches to fix them as a hobby? However, the conversation, interactions and framing are pretty casual, anchoring the story in reality rather than the playacted world of some older films or the multi-angle, high-octane visual amusement park ride of Marvel movies.
The film has an intriguing psychological theme at its centre that plays on familiar tropes while keeping the plot clipping along and remaining relatively original
As for the story, I can say without giving too much away that there is quite a bit of plot by horror movie standards. Moving beyond simple gore and jump-scares, the film has an intriguing psychological theme at its centre that plays on familiar tropes while keeping the plot clipping along and remaining relatively original. There are plenty of twists and turns plot-wise, with some predictable elements that are key to the horror genre and plenty of surprises as well. The conclusion will likely satisfy most viewers because it wraps up the story nicely and still leaves room for interpretation.
While the film references some historical themes, it doesn't go particularly into depth on any of them, which may lead to someone with absolutely no context feeling a bit lost--it's obviously not supposed to be a historical film or a lore-heavy quest full of long explanations, but viewers with some background knowledge on the Philosopher's Stone will get more out of it in my opinion. Additionally, there are some bits that are left completely unexplained and inaccurate--why is the information about the Philosopher's Stone that sets off the story in an underground cave in Iran? Why don't we see any payoff to the foreshadowing clues in the first 20 minutes or so of the film?
Some of the setup is a bit off as well: An older French or Aramaic manuscript uses Imperial units of "feet" to measure a distance below the ground, when that system wasn't used at that time or place. Lastly, the main character claims early on that she has a "black belt" in Krav Maga, when the highest level in IKMF and KMG is Expert Level 5. (KMW and FEKM use the belt system but a black belt is rare, especially if you also have multiple PhDs, speak 6 languages and are a 25-year-old Indiana Jones--everyone I've met nearing that sort of level is an instructor!)
I digress. Beyond those minor complaints, As Above, So Below is definitely a film worth watching if you enjoy horror, adventure films or anything involving the supernatural and paranormal with a historical twist.