Orphan

The six ponies and  Spike had been returned to the old castle in the Everfree forest one morning to clean it up. A week had passed by where Princess Celestia had showed them the box with the keys. After cleaning up in the old castle that day had Twilight been going to the library. That library had many old and rare books. The books had histories about the castle, the Everfree Forest and Ponyville through the years. Some of the other books had been about fairy tales and legends from the Everfree Forest. Twilight found an old book about the history of the castle.

"A long time ago Princess Luna and Princess Celestia lived in the Everfree Forest Castle." the alicorn read.

"Some years later had Princess Celestia moved to the Canterlot castle after banishing Princess Luna." Twliight were reading.

The book had been showing pictures of how the castle looked like before the castle got ruined.

"As Princess Celestia and the other ponies that worked in the castle had left to Canterlot, where nopony living in that castle for decades." Twilight read.

"It had been told that the castle had been left in a hurry one night, but for no known reason." Twilight were reading.

The book told that the castle suddenly got abandoned, and nopony wanted to go out there. Those ponies who went out in the castle to find out what happened on the past had suddenly been vanishing. Even pony ghost hunters who went out in the castle either ran away from the abandoned place, or got lost there.

"Ghosts from 1000 years ago were still around in the castle, while ponies vanished ." Twilight had been reading.

"Those who made it out of the old haunted place told other ponies that they had flashbacks, seen ghosts and heard unseen ponies talk to them in a very old language." the alicorn were reading.

While Spike and the ponies slept in the castle at night were the only hauntings flashbacks of how ponies lived there for 1000 years ago. There were no ghosts showing up, but at night these flashbacks came alive in dreams.