Byzantium,

Huge book - in size, breadth and impact. Telling a "history" of the Book of Kells we follow Aidan, a monk, as he becomes a slave, a Viking, a Sarazen.... A moving story of a man losing his faith, yet leading others to faith at the same time. Tremendous, both as a historic adventure "traveler's" story - and as an exploration of theodicy, bringing God to account for the ills in the world.

Notable too, as is Lawhead's recent trilogy, the Celtic Crusades, for a sympathetic treatment of Islam.