Takes place after the episode, "Bats!" where Twilight's spell didn't quite work out turning Fluttershy back. Little did she know, her and Fluttershy would have to face some unforeseen consequences.
Image © Joakaha on DeviantArt.
EDIT: Depending on time/motivation, I'm thinking of looking over this story again and seeing if I can expand on this. I originally intended this to be a short story/one-shot, but from the little feedback I got, I may revise and expand this.