Ambrose and his comrades have been marked for death by the emperor of Byzantium. Having being chased from Alexandria and crossing North Africa, they flee north through Italy, doggedly pursued by the Byzantine Admiral Demetrious. The Church attempts to help them, but the Byzantine Emperor has a very long reach. With the pass to France blocked for the winter, they find themselves trapped in northern Italy. Assassins come in the night, and their guides are bribed to kill them. Before the friends can escape through France to England, they must face avalanche, bandits, and savage Viking raiders.