It's Falconetti's face,somehow Dreyer managed to capture on film what seems impossible,such raw human emotion,a soul if you will,and the viewer is left drained at what they had just seen. I recommend the 24 frames a second with the 'Voices of Light' score,and watch it on the biggest screen you can find,because this is a life changing experience,transcendent even.Falconetti gives the greatest performance I've ever seen on film,and the director uses closeups for much of the movie,it's confrontational and brilliant,there is nowhere to look but at Joan,what she is going through,it's powerful stuff,your life will be elevated by just watching it.
Review of The Passion of Joan of Arc
