In tenth century Iceland a young woman, Thora Thorvinnsdottir, is orphaned at age fifteen, out of a home and close to destitute. Goaded by her misfortune Thora strives to fill in the gaps between the warp threads of her life's weaving pattern — which the Norns, maidens of fate, set up for each mortal as they see fit — with weft threads of her own choosing. She sails west to the new frontier of Greenland hoping to acquire a new farm of her own. In Greenland she agrees to a marriage ill-conceived to begin with, and ill-fated in the end. Thora joins her husband's timber-seeking expedition across the western sea to an unexplored land rumoured to be the source of driftwood littering Greenland beaches. In Westland they encounter novel forms of life — plants, animals and people unknown even to the most traveled Norseman among them, and Thora is given a chance to achieve a major goal she set for herself, in a way she never imagined.