After the death of his father, Robert the Magnificent, William, the disputed heir to the Duchy of Normandy, finds refuge in the village of Baligan. To escape the lords seeking to assassinate him and seize the throne, he hides under a new identity: that of a simple peasant named Hugo.

Taken into Cécile's family, Hugo must be careful not to attract too much attention because the lord of Baligan, Lady Néel, has tasked her chief of guard with finding him and keeping him out of the line of succession at all costs. When Hugo meets Algythe and discovers his affinity with the Runes, another part of his destiny becomes clear: renewing the spell created by his ancestor Rollo to keep Loki, the god of chaos, imprisoned in the cave of Baligan.

Thanks to his new friends, the teachings of the old bonesetter and above all his courage and his will, Hugo will prove himself more and more worthy of his destiny as the Chosen One.