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.

Thors and his men fall for Askeladd's trap and faces a dangerous situation, but Thors defeats many of Askeladd's men with his overpowering strength. However, Thors knows that it will be difficult to save everyone, including his son, who've been living in a peaceful village their entire lives, and makes a tough decision.

After Askeladd kills Thorfinn's father Thors, Thorfinn hides inside Thor's ship and bides his time until the opportunity to take revenge. However, life on the ship is harsh without any food or water, and Thorfinn grows weaker day by day. One day, Thorfinn, armed with his sword, attempt to attack Askeladd in his sleep...

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.

Canute’s party arrives in York to attend the Imperial Council. Although Canute had wanted to strike out against King Sweyn, the King was being guarded by the most powerful Jomsviking unit in the Northern Sea while keeping a close eye on Canute. With the situation strained to the breaking point, Askeladd comes up with a plan. Meanwhile, Thorfinn is reunited with a person who knew his former self.

After the assassination attempt on Canute’s life, rumors spread through York saying that the king is trying to kill Canute. As a result, the king is unable to issue any orders that would put Canute in harm, and Askeladd is pleased that everything is proceeding as planned. However, the tables turn when King Sweyn speaks. Meanwhile, Thorfinn is sent to prison as punishment for disturbing the peace.

Askeladd comes forth before King Sweyn and implores him to halt his invasion of Wales. Meanwhile, Thorfinn decides to return home at Leif’s urging. However, the moment before he boards the ship, Thorfinn catches a glimpse of a single tern taking off into the sky...

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

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.

After returning home to his farm, an exhausted Ketil starts searching for Arnheid, only to find out what happened in his absence.

Amidst the confusion of a peasant uprising, Thorfinn and the others try to escape, carrying a severely injured and pregnant Arnheid.

As Thorfinn and Einar head for their escape, Arnheid regains consciousness and asks where they are going — and if there are slaves and wars there, too.

The battle has left heartbreaking casualties in its wake. Though Thorgil and Ketil's wife want to continue the fight, Canute demands their surrender.

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.