Within a Sanctuary just built for her, a earth pony with secret knowledge is kept there outside from the world. So to obtain what she knows, the Princesses kept her there to only paint every few seasons, of her dreams and visions of another world.

Fluttershy had disappeared from a strange mist that covered most of Equestria for weeks. She, after being out in the mist for so long seemed to wandered off to the Everfree forest and in a strange side effect had lost her memory. Only to find a leaf.

A strange earth pony that lived in ponyville for so long, with no backstory of their childhood noticed apart of her own fur started to shed off. Replacing it, in an icky black. Believing in the afterlife she searched for a way to stop this.

A flash of a light and tires squealing wakes her up. A pony with no cutiemark and no memory of her past wanders through a strange world to discover who she used to be. While a strange dark entity lurks in the background to soon be discovered.

Sometimes you can find strange things in the Everfree Forest but what she found will change her life.

AppleJack finds an unknown pony around her farm covered from face to her legs with stitches. Later finds out that isn't the only thing very strange about her, even her own personality based around the cracks being her cutie mark is unpredictable.