When their mother dies, five little mice find themselves alone in an unforgiving world of constant danger. Two are taken by an eagle, and to make things worse, ice-season is coming. Without their mother's guidance, the remaining mice must leave their home mountain for the unknown to save their littermates and their lives.

Meet Feather, Snowy, Acorn, Spotty, and Twig on their journey beyond darkness, hail, and fire.