Late afternoon approaches. New York — a picture in gray. The city exhales a heavy, radiant breath. The air is still, even as voluminous thunderheads form. Soon their capacity to hold liquid is exceeded and dark bands of rain pour down onto the metropolis. Water cascades over glass and steel, swirls over pavement and concrete. Down into gutters. Down into sewers. The sun returns. On the vertical horizon, vegetation appears — distant and unattainable above the petulant democracy of the street. Here, a bird preens its feathers, and then flies away. Plants and flowers grow. Bees and insects thrive. A Green Roof.