The Snow-Walker's Son - Catherine Fisher

THE SNOW WALKER'S SON is a book of intrigue; of banishment and sorcery; of an ice cold winter and an unseen evil eye. Jessa and Thorkil are banished by the evil witch Gudrun to the ice kingdom to the North. Here they will be incarcerated with Gudrun's son Kari; about whom there are the most terrible tales. He is rumoured to be half-man, half-beast and is a figure of dread. After an endless journey, Thorkil and Jessa arrive and, at last meet Kari. He is not as they feared but is a slight winsome young man. His only terror is that he, too, has the power. But he is determined to use the magic wisely.