Muriel is mistress of the sea and of the water mirror, which shows the truth when the full moon shines. In return, the women of her family must marry only kings or lose their magic forever. Brendan is a prince, destined to be king. One stormy night, Muriel's powers save his life. Soon they are together in what seems the perfect marriage. When Brendan's true identity is revealed, his kingship is lost. Exiled from his lands, with Muriel losing her magic, they will have to find some new way to live... if they, and their people, are to live at all.