From the plane, the vast windswept desert and the red-brown mountains of the Sinai peninsula look like giant swirls raked across a sandbox. Then I see what looks like a discrepancy in the muted palette of browns and reds, and I look once again. Beyond and before the ribbon everything is brown. And yet there&rsquos this impossible green. Speed dissolves the mirage &mdash and, in the nothingness of the endless Western Desert that stretches across all of North Africa, appears the Nile. A thin blue line, with a green brush stroke on either side. As we start descending, minarets appear like pinheads in the clear sky. Indistinct greens resolve into palm trees and sugarcane fields, and the vast low-lying urban sprawl of Cairo emerges from the sands like a miracle.