Halloween drawing

I made this drawing right before Halloween at my drawing class last week. It is a very interesting technique; it was drawn by using the fire of a candle while placing the paper upside down to burn the paper, I used my fingers to blend the soot to give it shape.
I started with no idea on what I was going to draw. I started burning the paper randomly, and then I started seeing two faces developing. I used the fire to build up the shadows, and create contrast. Then I used my fingers and an eraser to emphasize the light areas, and define some details. It was pretty fun, I might make a whole series of these.