Equestria has been at peace ever since the defeat of Nightmare Moon and the chaotic forces that came before her. With Celestia's sister, Luna, now back and all old threats now kept in check, the land is in a peaceful harmony.
But that harmony came at a price that not even Luna was made aware....... until now.
Celestia has kept a secret that she has told no pony but one, and now that secret is about to step out of the shadows and into the light.