Cairo, 1167 AD. On the banks of the river Nile, from a palace of gold and lapis lazuli, the Fatimid Caliph al Hadid rules over a crumbling empire. His city is awash with intrigues and in the shadow of the Grey Mosque, generals and emirs jockey for position under the scheming eyes of the powerful grand vizier, Jalal. In the crowded Souk, these factions use murder and terror to silence their opposition...Egypt is bleeding and the scent draws her enemies in like sharks: the Sultan of Damascus, the pious Nur al-Din, whose master is the rival Caliph of Baghdad; Shirkuh, the swaggering Kurd who would lead the armies of Damascus to victory and then, of course, Amalric, Christian king of Jerusalem whose insatiable greed knows no bounds. Yet the Caliph of Cairo has an unexpected ally: an old man who lives in a place that even eagles fear. He is Shaykh al-Jabal, called the Old Man of the Mountain, and it is he who holds the ultimate power of life and death over the warring factions of the Moslem world, and it is he who sends his greatest weapon into Egypt, to serve the Caliph. He is but a single man but he is an Assassin: the one they call the Emir of the Knife...