At length Abdul took us along the Sharia Mohammed Ali to the ancient mosque of Sultan Hassan, and the towel-flanked Bab-el-Azab, beyond which climbs the steep-walled pass to the mighty citadel that Saladin himself built with the stones of forgotten pyramids. It was sunset when we scaled that cliff, circled the modern mosque of Mohammed Ali, and looked down from the dizzy parapet over mystic Cairo—mystic Cairo all golden with its carven domes, its ethereal minarets, and its flaming gardens. Far over the city towered the great Roman dome of the new museum; and beyond it—across the cryptic yellow Nile that is the mother of aeons and dynasties—lurked the menacing sands of the Libyan Desert, undulant and iridescent and evil with older arcana. The red sun sank low, bringing the relentless chill of Egyptian dusk; and as it stood poised on the world's rim like that ancient god of Heliopolis—Re-Harakhte, the Horizon-Sun—we saw silhouetted against its vermeil holocaust the black outlines of the Pyramids of Gizeh—the palaeogean tombs that were hoary with a thousand years when Tut-Ankh-Amen mounted his golden throne in distant Thebes. Then we knew that we were done with Saracen Cairo, and that we must taste the deeper mysteries of primal Egypt—the black Kern of Re and Amen, Isis and Osiris.