The American Version

You can't understand the American version because it is so heavily cut, it is nonsensical. The main difference with the American cut is that it is short and resequenced. Also, the music is different - it is far more suited toward a horror films with chilling sound effects and some outtakes of Isabelle Adjani growling in the subway stations. Additional scenes: Apart from the monster's eyes in Adjani's hands, there is a little more of the bleeding scene in the subway station. Also, we see alternate takes of some scenes (for example when Adjani first hits the detective on the head with the broken bottle, in the European cut we see it from Adjani's angle but in the American cut we see it from the detective). The also added some weird special effects, like flashing of colour here and there.


By the way, even the European cut is not the full cut. In the subway scene, (apart from the monster's eyes and some extra bleeding), Adjani grabs the wall and bends at the waist and starts to growl just after she smashes her groceries on the wall. Neither the European cut nor the American cut feature this scene. This scene was only shown when it first premiered at Cannes, I believe. You can see that extra little bit of the wall-grabbing subway scene missing in both versions here:

http://www.ina.fr/art-et-culture/cinema/video/CAA8100729001/cannes-possession.fr.html


Here is a still of the monster's eyes appearing in Adjani's hands during the subway scene:

http://img231.imageshack.us/img231/7458/eyenc.jpg


In the American version, they sampled Adjani's growling as part of the soundtrack and multi-tracked it and then gave it some echoey effects. This part can be heard at the end when Mark is on the stairwell and bleeding.