Princess Luna stood on the top of the library looking out across her land. Down below in the community of Ponyville, everypony was celebrating, some of the older and stronger ponies working together to tear down the gallows and electric fence. Fillies and colts were engaged in their games, something they had never once had the chance to do until now. The sun shone on through out the day, its heat and light casting waves of hope across the beautiful spectacle.

The Princess of Day and Night remained at her post on the top of the library for much of the day and well into the night. When night fell, many ponies grew afraid, fearing that the day was a onetime thing, but Princess Luna assured them the sun would rise again. She just  hoped she remembered how to raise it...it seemed like so long since her sister had showed her.

Luna had considered the possibility of her sister returning when the sun rose...it wasn't impossible. She waited through the night patiently, waiting for the moon to finally complete its pilgrimage across the night sky. When the time came to raise the sun, she would find out once and for all if she was worthy of being the sole reigning sister with such a responsibility. She knew there would be hard times ahead...she knew not all the ponies in Equestria trusted her right now. Many of them had looked hopefully at the first sunrise for the return of Princess Celestia, only to be let down when she did not return. Other ponies still cowered fearfully around her, despite her best efforts to appear friendly and welcoming. She smiled, spoke with her subjects, trying to build as much trust as she could. For the most part she was successful.

For the most part.

The moon was dipping over the horizon now, most of Ponyville looking to the East for the sun. It was time...

Princess Luna flew into the air, following the sun upwards as she focused all her magical ability in raising the Equestrian star into their earthly sky. When its light began to shine across Equestria, another collective cheer grew out among the watching ponies. Luna turned around to smile at her residents, who were again celebrating the coming of a new day. Perhaps she would partake in some of the festivities today...

Instead of flying down immediately, Luna continued looking hopefully to the East, eagerly anticipating the return of her sister. As she continued to wait, the sun rising slowly, its light growing brighter, the minutes passed slowly, and Princess Luna knew that her sister would not be returning.

"I don't know if you can hear me, sister...I doubt you can, from wherever you are...but if you can, I hope you understand how much I miss you...I hope you understand how much I wish I were with you right now."

And yet Luna knew deep inside her time to join Princess Celestia was not anytime in the near future...as long as she reigned over Equestria, she would remain immortal, ageless, watching as her subjects lived and died, hopefully happily, as new generations bled from the old ones, as Equestria shifted and changed, she would remain the same, and Princess Celestia would never return. Such was the way of life. Without anypony to take her place on the throne, with the only bearer of the Element of Magic gone, most likely forever, she would remain alone for a long time....her punishment, she supposed, for what she had done.

"I'll see you again sister...I know we'll see each other again..."

After all, nothing lasts forever.

In another world, one without sound nor light or colour, a purple unicorn opened her eyes suddenly and looked frantically around. Her name, her past, her present location, it all escaped her fervent and panicking mind.  

"Hello, Twilight Sparkle," An icy voice suddenly called from the darkness and she started thrashing around, looking for the source. To any other pony it would be the voice from a nightmare, the fearful whisper of darkness and despair.

But to the allegedly deceased Twilight Sparkle, the voice of her beloved mentor was one of hope.

Hope for revenge.