"Metamorphose I" by Escher is the first step on the road to madness! Somehow this visual genius manages to transform the cliff-top town at the left of the image into the small mandarin figure on the right. How he does it, with the use of mathematical modification of shape, from town, through cubes, and then into a figure will have you studying this image from the moment it arrives in the mail. It is addictive, it is clever, and it deserves a place in your life."