Christ Church Priory, Canterbury, 990 AD. Orphaned by vikings, Folcwin and his elder brother Aelfwynn have become excellent scribes.

Their lives, enlivened by sibling rivalry, are upset by a competition to illuminate a commissioned psalter. After Folcwin is selected the victor, his brother is accused of murdering another competitor, and he escapes. While Aelfwynn begins a patriotic battle against Viking raiders, Folcwin's fame as a scribe increases.

Even with their imbalanced fortunes, the paths of the two brothers are bound to cross with powerful kings and strong leaders, including King Aethelred, Thorkell the Tall and Edmund Ironside. But can they overcome the Viking menace?