Oddny and Gunnhild meet as children in 10th-century Norway. After a visiting wisewoman makes an ominous prophecy that involves Oddny, her sister Signy, and Gunnhild, the three girls take a blood oath to always help one another. When Oddny’s farm is destroyed and Signy is kidnapped by Viking raiders, Oddny is set adrift from the life she imagined --- but she's determined to save her sister, even as she finds herself drawn to one of the raiders who participated in the attack. And in the far north, Gunnhild, who fled her home years ago to learn the ways of a witch, is surprised to find that her destiny seems to be linked with that of the formidable King Eirik. But the bonds that hold the two women together are strong, and when they find their way back to each other, these bonds will be tested in ways they never could have foreseen.