1098. Having settled their differences with the Byzantine Emperor, the armies of the First Crusade race across Asia Minor, routing the Turks and reclaiming the land for Christendom.
But on the Syrian border, their advance is halted before the impregnable walls of Antioch. As winter draws on, they are forced to suffer a fruitless, interminable siege, gnawed by famine and tormented by the Turkish defenders. Divisions appear: between the squabbling princes who lead the crusade; between the lords and the men they lead; and between the Westerners and the Byzantine forces who accompany them.
The entire crusade is on the verge of collapse. In the midst of this misery, a Norman knight, Drogo, is found murdered. Drogo's lord, the ruthlessly ambitious Bohemond, charges Demetrios Askiates to find the killer, suspecting it may have been a follower of Bohemond's rival Count Raymond. But as Demetrios investigates, the trail seems to lead ever deeper into the vipers' nest of jealousy, betrayal and fanatacism which lies at the heart of the crusade. Other forces are equally threatening. A great Turkish army is fast approaching to relieve the garrison of Antioch: unless the crusaders can bury their differences and take the city, they will be crushed before its walls. Ever more isolated, Demetrios must ally with Bohemond if they are to have any chance of finding the key which will unlock the gates of Antioch. Once the crusaders are inside, however, they will discover that their greatest trials have barely begun.