It never happened.

The Crystal Heart was never brought back to the Crystal Ponies. King Sombra successfully took back the Crystal Empire and declared war on Equestria.

Underpowered and unprepared, Equestria is barely a match for Sombra's army. Everypony needed to do their part just for the war to reach a stalemate, but is their a glimmer of hope within the hearts of some?

This is a rewrite of a story I wrote a few years ago that I decided to re-do from scratch.