When Ragnar Magnusson has to do battle with the high seas and an ancient mariner and navigator of the ship, part of his bravado is for Helga, also on board The Battlestormer. A young man on board with his three boyhood friends, Ragnar is singled out by the ship's navigator to become his apprentice in the art and science of navigating the oceans. Captain Leif Knutson is in search of the fabled Vinland the Good, exploring for King Sigurd, and he hopes to open up timber and ore trade in the newly found lands far to the west of Greenland. When Thorhall the Navigator passes all his knowledge on to Ragnar, Son of Magnusson, the old man dies, leaving Ragnar the most important man on board - the navigator. Helga and her ailing, dying mother are traveling to Vinland to join with her father. Once there, Helga, who has been promised to Ivar Bloodax in marriage before she was born, believes she must go through with the "slavery" in question as she puts it. On board too are Kark, Ragnar's own family slave, and Grimwold, the bullwhip-carrying boss man to the oarsmen.
Even before they locate Vinland, where Helga's father rules as Halfdane the Godi (village elder), Ragnar decides to challenge Ivar Bloodax for Helga's hand in marriage as the two have fallen in love during the treacherous voyage from Greenland to the new continent. Both Kark and Grimwold set about training the "boy navigator" in the art of self-defense and offense with a sword against a man with a battleax, a warrior twice his age who has a reputation so large he is the subject of a Saga. From the moment Ragnar makes his lawful challenge, intrigues of another kind begin to suffocate and attempt to destroy his love for Helga, who has her own secrets. Ragnar is also betrayed by one of his closest friends. As the obstacles mount, Captain Knutson and the crew of Battlestormer are also confronted with Skraelings - Native Indians - who are out for a vengeance of their own.