It's actually based on Thierry Jonquet's 'Tarantula', a book he wrote a long time ago. He passed away some years ago, in 2005 IIRC. Almodovar's films have always had a sexual nature to them, and when I heard he was optioning the story I just couldn't imagine how twisted this could end up being. I watched the movie a couple months ago, and I wasn't impressed. He probably had a fascination with the story, but even the violent scenes and all that were not really that much, at least compared to other films. I was probably more shocked when I watched 'Irreversible', when Monica Bellucci gets abused for like 7 or 8 minutes. THAT was disturbing.