In the year 1012, England’s Norman-born Queen Emma has been ten years wed to an aging, ruthless, haunted King Æthelred. The marriage is a bitterly unhappy one, between a queen who seeks to create her own sphere of influence within the court and a suspicious king who eyes her efforts with hostility and resentment. But royal discord shifts to grudging alliance when Cnut of Denmark, with the secret collusion of his English concubine, Elgiva, invades England at the head of a massive viking army. Amid the chaos of war, Emma must outwit a fierce enemy whose goal is conquest, and outmaneuver the cunning Elgiva, who threatens all those whom Emma loves.