A new venture from the author of the Pendragon Cycle (The Endless Knot, 1993, etc.), though here the fantasy elements--ghosts, angels, some prophetic dreams--are all but imperceptible. In the tenth century, the Irish monks of Kells have prepared a magnificent illuminated manuscript, its cover splendid with silver and jewels. This Book of Kells will be presented to the Holy Roman Emperor at Byzantium. One of the monks chosen to accompany the gift is pious young Aldan mac Cainnech, who dreams of the Emperor's fabled city and foresees his death there. Off Brittany, however, the monks' boat is sunk by Vikings, and Aldan is carried off to be a glare to the warrior Gunnar in distant Sweden. Through his learning, piety, and quick wits, Aidan catches the attention of the Danish King, Harald Bull-Roar, who nurses grandiose plans to sail south and east to sack Byzantium. But when Harald and his small fleet finally reach the huge, opulent, powerful city, he realizes the impossibility of his ambitions, and only Aldan's knowledge of Latin and Greek keeps the warriors out of trouble. After a dispute with a city official, Harald and Aldan come before the Holy Roman Emperor, Basil, who not only agrees to the justice of their claim, but hires the Danes to protect a diplomatic mission to Trebizond, where Basil hopes to conclude a treaty with the Arabs. And in agreeing to become the emperor's spy, Aldan will lose, then eventually regain, his faith, and experiences betrayal, further enslavement, a reunion with friends long thought dead, intrigues, a return to Sweden, and a final spiritual triumph. Far-fetched but often engrossing, with plenty of plot twists despite Lawhead's sometimes shaky grip on the details: Worthwhile for Lawhead regulars and historical-fantasy fans alike.