Thorfinn, a boy living in Iceland, longs for adventure and is eager to know more about the world. He dreams of a land of paradise called Vinland that he hears about from the adventurer Leif, while he leads his peaceful life with this father Thors, a former warrior. One day, Thors saves a runaway slave and sets a series of events in motion. This is the story of a true warrior in an age of turmoil.

In the year 1002, the war between England and Denmark was intensifying. One day, the Jomsvikings pay a visit to Thorfinn's village in order to bring back Thors, their former commander, to prepare for the impending battle. Thors is forced to join the war in order to protect the villagers from being taken hostage, and must face his accursed past in order to save his family and his village.

Askeladd, the leader of a Viking army of a hundred men, receives orders from Floki of the Jomsvikings to kill Thors, who was once known as the Troll of Jom. However, the villagers, completely unaware of the order, buzz with excitement as they prepare for their first battle. Thorfinn also joins in the excitement. Thors and his men are about to embark on a difficult sea journey to England.

Thorfinn kills his first man. As more time goes on Thorfinn kills more men and becomes more skilled. One day when Thorfinn is in battle he gets shot with an arrow and ends up unconscious. An English woman and her daughter help him recover.

Askeladd withdraws temporarily from the war against England. While searching for a new source of income, he encounters a skirmish among the Franks and hatches a plot to steal their treasure. Askeladd sends 16 years old Thorfinn, who has grown up into a cold-hearted Viking, ahead as a messenger.

Askeladd's army separates from the army of Denmark and attacks a village 100 km to the west. Thorfinn leaves the soldiers behind in disgust and climbs up a hill overlooking the village, where he pledges revenge for his father. However, he encounters Askeladd sitting in the darkness, who tells him about "Britannia", the aging of the world, and Ragnarok, the final battle.

Askeladd and his men continue their march to escape from Thorkell. However, their march comes to a halt at the Severn River. Askeladd hands a letter to an old man operating a ferry across the river and tells him to deliver the letter to the other side immediately. As soon as he hears the addressee’s name, the old man sets off in his boat.

Thorfinn suffers a serious injury in his fight against Thorkell. Thorfinn is told to think about what he has to do to beat Thorkell. Askeladd treats Thorfinn’s wounds so that he may fight again someday, and proposes a joint strategy to help the two of them survive longer.

Einar lives peacefully in northern England with his mother and sister, but then one day, their village comes under attack.

Einar and Thorfinn are told to convert a wild forest into a wheat field; and if they succeed, they will have the chance to buy their own freedom.

The farm guards convince Ketil’s 17-year-old son that he needs to make his first killing to become a man.

While in Jelling, Ketil, Thorgil and Olmar meet a man named Leif Erikson who is searching for Thorfinn, the son of his close friend.

Olmar feels insulted by Canute's messenger and, encouraged by his older brother Thorgil, takes matters into his own hands.

At long last, Thorfinn returns to Iceland and finds a moment of happiness, reunited with his loved ones. But soon, he opens up about his next journey.