Plotting to avenge a massacre in England, Viking armies converge in Kattegat — but siblings Leif and Freydis exact a different kind of retribution.

To save the life of Freydis, Leif agrees to join Canute and Harald's siege of London. Queen Emma dispatches stepson Edmund to secure an ally's help.

On a pilgrimage, Freydis and her party are savagely attacked. Harald and Leif seek a route through the marshes near London as Edmund is crowned king.

Leif proposes an audacious assault on London, one that Emma and Godwin fear their brash and headstrong boy-king, Edmund, will be too reckless to defeat.

Schemes, betrayals and politics rule the day as a new monarch takes the throne of England. Leif is hailed as a hero but secretly questions his faith.

Freydis returns to Kattegat and joins a sacred order. Canute solidifies his power in England. Kåre revisits the holy site of a childhood trauma.

Olaf makes a pact with Kåre as Kattegat prepares for its defense. In Canute's absence, his father, Sweyn Forkbeard, shares England's throne with Edmund.

Olaf and Kåre gather their forces to invade Kattegat. Palace intrigue over control of England's throne results in an unexpected turn of events.

Olaf lands in a terrible position after Forkbeard invades Kattegat. In hiding, Freydis and Harald must decide whether to fight for the throne or flee.

Freydis finds a new home. Harald formulates a daring new plan to take back Norway, but Leif's not on board. A new threat appears in London.

While preparing for a journey to Constantinople, Harald assembles an unlikely crew, each with their own motives. Emma suspects Godwin of treachery.

The travelers make a deadly miscalculation on the way to Constantinople. Olaf sets off after Harald, and Emma's paranoia pushes her over the edge.

Harald learns a devastating secret. The group encounters a dangerous stranger. Harekr reveals his true intentions for the future to Freydis in Jomsborg.

Love blossoms on the ship as the crew makes a fateful decision, with Olaf hot on Harald's heels. Jormundr stands trial. Canute makes Godwin an offer.

Harald makes a risky move and falls into the hands of the Pechenegs. Olaf sets out to find Jomsborg and stumbles upon an unlikely source of help.

Leif says a painful goodbye. Harald's new love is not what she seems. A key battle comes to an end, but the war to rule over Norway is just beginning.