Let's get one thing out of the way first: it's an art-house fare that shifts between different genres (not even trying to be seamless) and is comfortable with it and it also definitely should be avoided by all people who are not fans of narrative structures that aren't, well, exactly straight-forward. If you're more open to experiments and weirdities that festival cinema offers, you might be in for a treat.
The movie starts out as a detective with hints of something supernatural to come. Supernatural does indeed come quickly but then -Bam!, movie starts to present itself as mockumentary with director and various other people, some of whom are directly related to the main characters, talking about the events that happened in the past. And then it shifts back to the fictional action that starts to lean towards something vaguely resembling a spy thriller while at the same time continuing the first story-line. But then mockumentary kicks back and so it continues towards the end, with characters in the present explaining some of the events and back-stories of the fiction (or not fiction?) we see in between. There's some scary suspense thrown in as well as our main characters try to uncover the mysteries in the desert. One of the "real" real characters turns out to be playing himself in the "movie" part. Objects from the "movie" part begin to appear in the future part that is the mockumentary.
At times it is a bit complicated to follow but compared to some surrealistic movies like last year's "Reality" it's easy. The pace is patient and not everything gets explained completely but the main story-line wraps up nicely and in the end. The film does wander quite a bit between all the different sub-plots and at times you might just wish that it would stop switching to the documentary-mode but patience is rewarded.
Besides, acting is on point, even if there are no stand-out performances here, cinematography is gorgeous and gets complimented nicely by the stylish period costumes, some of which look totally surreal in the desert landscapes.
The soundtrack deserves a special mention, with the Arabic motives overridden by western-style thumping electronic rhythms. Yes, it's been done before but it's nevertheless done great here again.
I fear that us western viewers might miss some (if there are any) metaphors or allusions but it doesn't take away from the fact that the movie is totally hypnotic, intriguing, beautiful and never predictable. In the end, I loved it.