Cairo, 1167 AD.
On the banks of the river Nile, from a palace of gold & lapis lazuli, the Fatimid Caliph al Hadid rules over a crumbling empire. His city is awash with intrigues & in the shadow of the Grey Mosque, generals & emirs jockey for position under the scheming eyes of the powerful grand vizier, Jalal. In the crowded Souk, these factions use murder & terror to silence their opposition... Egypt is bleeding & 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 & 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, & it is he who holds the ultimate power of life & death over the warring factions of the Moslem world, & 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...