When Autumn wakes up one day, in a strange new place, she meets a squirrel called Ellie who tells her she is the new Guardian who must dedicate herself to protecting the forest and all its inhabitants. The squirrel also sounds a note of caution however, that Autumn should never go to the edge of the forest because of the evil that lives there.

Soon, Autumn is enjoying her new role as forest Guardian and making lots of new friends as well. With a little hut to call home and a purpose in life, she couldn't be happier.

But the good feelings don't last. While picking acorns one day, Autumn strays towards the edge of the forest and there she encounters an evil presence that only wants to destroy.

As an all-consuming rot descends on her once beautiful home, Autumn sets off on a quest to find an answer that will help her to stop it. But will she discover the reasons behind this malign presence and its unstoppable power? Or will she eventually come to understand why it is necessary?