The cast, the camera work, the music and the dialogue all create a dark and surreal tone that's haunting and riveting. Tim Roth, Renee Zellweger and Ellen Burstyn all dominate so completely that you can't look at anyone else when they're onscreen. It's as much an exercise in acting and "mood" as anything, but the story is fun to follow. I don't think it's supposed to be "believable" in the literal sense. How can it be when they throw in epilepsy, absinthe, prostitution, family dysfunction, etc. Every character was well-cast (LOVED the psychologist) and the tension and undertones in the actor's interactions with each other make it an impossible-to-forget movie. It's one of the few I own. The scenes with Mook (Burstyn) as well as those with Roth and Zellweger are ingenious. A movie that must be watched closely to understand the ending.
