For centuries the Byzantine Empire has been in decline; now the capital of the world lies open to the rampaging Turkish army. Only the promised arrival of the First Crusade will save Byzantium and Christendom itself. As the Empire hangs by a thread, a mysterious assassin looses an arrow at the Emperor. The Emperor survives, but only just. The assassin must be stopped before he strikes again. Demetrios Askiates is an investigator of mysteries. His job is to find the would-be killer. But soon he is in the eye of a storm as the Crusaders make camp outside the beleaguered city, as intent on looting, destruction and intrigue as their Turkish enemies.