Everyone around the world with access to a television set saw the cataclysmic destruction of the World Trade Center towers, saw it in constant replay, burning—and burning itself into our collective retina. I saw it that way too, but first saw it unmediated. On September 11th my wife, Françoise Mouly, and I had just stepped out of our Lower Manhattan home. Those towers had been our taken-for-granted neighbors, always picture-postcard visible a mile south of our front stoop. That morning, out of the very clear, very blue sky, a plane roared right over our heads and smashed into the first tower.