In an attempt to gain Twilight Sparkles aid in protecting Equestria Princess Celestia attempts to teach her a new spell. However the spell misfires and Twilight comes face to face with Shadow Shimmer. Who warns the princess is not who she seems. Celestia tells a story of the greatest mistake she ever made and must get Twilight to help her in fixing a threat she cannot face alone.
Of unlimited pontential what is Shadow Shimmers true intentions. A tale of sorrow and pain of a life without friendship that spirals into a stunning finish.