J.S. Frankel

Erik Jonsson, adopted by the Jonsson family, is devastated after the apparent death of his sister and girlfriend, Lara. But when his father reveals she's trapped in another realm after casting an ancient spell, Erik follows her. He arrives in a village resembling 1700s Iceland, ruled by Einar, a warrior-priest who bargained with the devil for immortality in exchange for a thousand souls. Erik finds Lara, but escape isn't simple-there's no obvious way home.
With just thirty days to uncover the spell that can return them, Erik and Lara must race against time-or be condemned to remain among the damned forever.