Asa Coppermane is the proud daughter of a Viking chief. Asa and her horse, Rune, are creatures of the sea and the cold northern lands. But this winter has been the worst one Asa has ever seen. Her father and the other men have gone to sea to search for food, leaving behind the women and children, many sick with fever.

Also left behind is Jorgen, the clan's wise man. His stories are meant to comfort them all, but Asa suspects that what Jorgen really wants is power. Now that her father is gone, Jorgen demands Asa give up Rune -- for food, and as a sacrifice to the gods.

When Jorgen comes to kill Rune, Asa fights him off and she and the horse flee. They find shelter with a one-eyed old woman who speaks to her two pet ravens, and who seems to have a strange power over Asa. The old woman hints that Asa must make a sacrifice to save her clan -- but how? And what kind of sacrifice? What are the secrets of the raven speak?