This is one of those psychological horror films that needs to be chewed on and pondered over after watching it. After having done so, give it another watch and gain more insight. Like many others have mentioned, this film is a slow burn that relies on the very capable actors, atmosphere and just great storytelling. There is no cheap jump-scares and other cookie cutter horror cliches like most of what Big budget horror dishes out to us one after another. This is well done, creepy, tension-building, storytelling! For those that are students of the occult, you will definitely have a heads up on this particular ritual (Abramelin), albeit a tad bit overdramatized. Beautiful cinematography, awesome score, very well acted and scary. Highly recommended!