I read "Under The Skin" by Michel Faber thirteen years ago whilst enduring a prolonged stay on a psychiatric ward suffering from abject terror. It was probably not the most suitable book to read under the circumstances but, on the other hand, it is such a weird and unsettling book it managed to register in my mind even though my thoughts were predominantly taken up with other things.
The film "Under The Skin," directed by Jonathan Glazer and starring Scarlett Johansson, is so loosely based on the book that I'm surprised the producers had to pay Faber for the rights. Everything in the film is different to the book. Even the message of the film is a different one to that posed by Faber in his novel. However, I suspect that I understood what was going on in the film only because I was familiar with the original story. Someone just watching the film as a stand alone would have probably spent most of its duration wondering what the heck was going on.
As an example of slow film I rate "Under The Skin" very highly indeed. If I had been looking forward to a good yarn I would have been disappointed but I've always been able to enjoy movies just for the pretty pictures so I'll give it four out of five.