The first steps are made of stone, and the air is dry and musty. After the turning of the stair, my feet find wood, and I smell dead leaves. After the second turning, the treads are made of ash, and then after the third I am no longer descending a stair at all, but walking on a desert of black sand. From the dune beneath my feet down to a wide river delta, there is no colour other than black. It is, though, a rich black, fertile with textures and depths, so that although there is no sun in the endless darkness of the sky, still each stone and stunted tree is quite distinct from everything else, made so by its peculiar arrangement of shine and roughness.