The Year of our Lord 968. 

Attracted by the riches of the Christian kingdoms in the Iberian Peninsula, a fleet of fearsome Nordic warriors threatens the flourishing town of Compostela, a bastion of the Church and the Crown, leaving only desolation in their wake. As they make their way up the river on their drakkar ships, going against the rapids, they leave devastated villages and fuming ashes behind them. The same fate befalls Outeiro, the small town where Assur lives, a boy who, after the tragic death of his parents, has no choice but to take refuge in the hope of finding his brothers, captured by the terrible invaders.

Gutier de León, heir of Count Gonzalo Sánchez, meets the young man and takes him under his wing. Thus Assur meets Jesse ben Benjamin, a kindly Jewish doctor, and Weland, a Norman mercenary in the service of Christians. Together with them, he learns everything necessary to face his destiny: he acquires knowledge of the science of his time and delves into the art of war. However, when he tries to rescue his brother, in the great battle being waged in the Strait of Adobrica against the northern invaders, he is imprisoned and dragged to the frozen lands of his enemies, where he will have to make use of all his will and courage to get away.

As an escaped slave, Assur will survive as a whaler, and fortune will escape him until, as a reward for an incredible feat, he manages to enlist aboard the ship captained by the renowned Leif Eiriksson, son of the founder of the Groenland colonies. Together with him, Assur will travel to Vinland, the unknown land to the West, and will survive the most unexpected dangers. He will be betrayed, suffer the harshest winters, fight for the love of a woman, face unknown enemies, and tirelessly search for his missing brothers, but, above all, keep a single hope alive: to return back.