Thousands of years ago there was a great distrubance in Equestria, an event that changed the lands forever. However, almost all memories of this have been lost to time, even the tales passed down from generation to generation eventually being discarded as bogus or fairytales.

Of course not all who lived through this have passed on. The Equestrian Royal sisters still hold those memories, although they have tried to lock them up and not discus the horrors that unfolded. Just as they princesses began to forget about the atrocities they had witnessed, something changed. They started seeing things that should not have existed for thousands of years.