Fifteen years ago, the Viking commander, Thors-Snoresson, deserted a naval battle and began a peaceful life in Iceland with his wife, Helga. Now in the year 1002 their young son Thorfinn longs to see the heaven called Vinland. However, Viking Floki arrives in Thorfinn's village planning to kill the boy's father, Thors, who is revealed to be the previous Jomsviking. After his father's death, Thorfinn joins the Ashilad crew to avenge his father and constantly challenge his captain to various duels. By 1013, the Askelids had found employment as mercenaries in the Danish invasion of London under Thorkell the Giant.

The two Viking bands later clash when their commanders seek to capture the young Danish prince Cnut, Ashelad's group succeeds but Thorkell's forces force them to take refuge for the winter in the frozen north of England near the Danish camp at Gainsborough. Finding a reluctant Cnut unmannered and too dependent on his deputy Ragnar, a disappointed Ashelad briefly changes his initial plan to support the prince to hold him to ransom. But a sudden attack from Thorkell's company forces Ashelad to change his mind, and he kills Ragnar to force Knut to defend himself. The Prince brings both Thorkell and Ashelad's remaining forces under his command as he confronts his father, who decides not to kill Cnut after proving his worth, while insisting that Harald be his heir.