The Book of the Sword — A.J. Lake

Snatched by a dragon at the end of book one, Edmund and Elspeth awake to find themselves soaring over the frozen wastes of the Snowlands, hundreds of miles from home. Escaping the dragon's clutches, they are discovered in the soft snow by Fritha. a charcoal burner's daughter. Edmund wants her help to arrange a passage home, but Elspeth has other ideas. The sword is speaking to her, filling her thoughts more and more. It's destiny is nearby, the purpose for which is was hewn, and where the sword goes, Elspeth must follow, increasingly under it's spell. Edmund and Fritha refuse to let Elspeth travel alone, and so they set out together on a perlilous route to Eigg Loki, the mountain which is drawing Elspeth and the sword, and to the dark secrets which lie at its heart.