Young Sorcha is the seventh child and only daughter of Irish Lord Colum of Sevenwaters, a domain well protected from invading Saxons and Britons by dense forest where, legend says, fey Deirdre, the Lady of the Forest, walks the woodland paths at night. Colum is first and foremost a warrior, bent on maintaining his lands against all outsiders. Not all of his sons are so bound to the old ways, and that family friction leads to outright disobedience when Sorcha and her brother Finbar help a Briton captive escape from Colum's dungeon. Soon after, Colum brings home a new wife who ensorcels everyone she can't otherwise manipulate. By her spell Sorcha's brothers are cursed to become swans. Only Sorcha, hiding deep in the forest, can break the spell by painfully weaving shirts of starwort nettle--but then Sorcha is captured by Britons and taken away across the sea. Determined to break the curse despite her captivity, Sorcha continues to work, little expecting that ultimately she will have to chose between saving her brothers and protecting the Briton lord who has defended her throughout her trials.