Snow-Walker by Catherine Fisher

A Fantasy Novel based on Icelandic, Norse and Celtic Myth.

Evil witch Gudrun has ruled the realm for ages. Her time is at an end however. A group of courageous folks including Wulfgur the rightful Jarl and Kari, Gudrun's son have taken back the realm. Kari is a mirror image of his mother and has as much power as she but is only learning to use it. Gudrun had kept him imprisoned in a small dirty room all these years claiming him to be a monster. Gudrun promises revenge. She steals the soul of Wulfgur's beloved and takes it to the land of the snow-walkers across the ice bridge a land no human has ever returned from. Kari and the others set out to rescue the soul of Signi and release the realm from an icy dream sleep. They meet some incredible people along the way who help them reach their goal. There is the shapshifter/wolf and a skraeling woman, keeper of goats among others. They fall into traps set by Gudrun which they must overcome. Often it looks as if they will fail. This is a perfect story for readers of Garth Nix and Philip Pullman.