Seventh-century Ireland is becoming a land of saints, scholars, and spiritual foster mothers as well as warriors. The boy Aidan, a descendant of Saint Brigid, is formed by all of these as well as by a pilgrimage, aborted by an Arab uprising, on which he meets a follower of the Prophet Muhammad. He is transferred to Iona, the mother-house of Saint Columba's family of monasteries, where his character is forged. Aidan becomes guest-master to challenging visitors, one of whom conducts a mysterious affair, suffers a midlife crisis, and develops friendships with royal Saxon exiles at the Dunadd court, the seat of the "real" King Arthur. Iona commissions Aidan to evangelize the original WASPs: the White, Anglo-Saxon Pagan invaders of Britain. Aidan offers a radically different approach to that of the Roman missionaries. His gentle grassroots gospel-sharing through friendship, his villages of God that model God's kingdom, his introduction of spiritual foster-mothers such as Hilda to the English, his soul friendships and heartbreaks with successive saintly and power-hungry kings, and his near-death foresight into the future take us inside the heroic spiritual formation of a person and a people in a story that has contemporary significance. Even Aidan's name, Flame, tells a story of its own
