All her life, Rin Nowell has dreamed of adventuring beyond the quiet borders of her village. What better opportunity to explore the world than traveling to find her long-lost mother? But what was supposed to be a short journey becomes a fight against the elements in the blizzarding mountains. Lost and discouraged, Rin meets Zarus Lowwenth, a mysterious person living on the lonesome mountains. Distrustful of the stranger, but having no other options, Rin accepts his offer of shelter and follows him to his eerie castle. But as Zarus offers Rin a map to find her way off the mountain, Zarus's old demon mentor, The Dark Tyrant Eretimis, shows up unannounced and seeking his allegiance. Zarus refuses, and before Eretimis disappears, the Tyrant threatens to kill Rin. Suddenly thrown into a world of demons and magic, Rin must flee the frozen mountain and escape Eretimis's threat. Zarus volunteers to guide her to safety, but while they run, Eretimis issues a bounty on them... and his loyal eyes are all over.

The duo forms an uncanny friendship as they face one trial after another at the hands of Eretimis's loyal subjects. If Rin is caught, she will never learn why her mother abandoned her twelve years ago. If Zarus is captured, he will be forced to succumb to the Dark Tyrant's rule after a lifetime of running from it. Fate may be out of their control, but neither will surrender without a fight.