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.