Charlemagne, the King of the Franks, is returning from an unsuccessful invasion of Spain through the Pyrenees. Waiting in ambush are the Basque tribes.
The story unfolds through the deathbed confessions of an Old Basque Warrior. He has been poisoned and left to die outside the gates of a Benedictine monastery in the high pyrenees. At first the monks do not take him seriously. He is delirious and not making sense, but then he suddenly has their full attention when he says,
"What I shall tell you is how a young Nagusi warrior made it possible for us to defeat Charlemagne, safequard our two provinces in France and the part he played against the Sisters of the Moon."
At the mention of the Sisters of the Moon, the monk's faces turn pale. The Old Warrior has revealed that he has secrets that they, as Charlemagne's spies, the Benedictine monks want to know. In a series of flashbacks the Old Warrior reveals the power of the Nagusi. The story of a young warrior who has become a Nagusi and then he reveals the heroism of this young warrior's deeds with his companion, Storm, his trusted Wolf-dog. The book is a historical thriller, based on actual historical events.