It has been well over a thousand years since their so-called 'banishment'. Their unjust imprisonment, confinement in pure darkness. But the show must go on, for all the world is a stage, and they knew that with time, their final act would await.
Tempest Shadow has an untold past that nopony really understands. One day, she tells Twilight Sparkle what actually happened on the day she lost her horn and also learns a valuable lesson; that everypony is truly wonderful in their own way...