Twilight finds an old journal written by her ancestor Fiona Alyssa Sparkle detailing events untold as of yet by the history books about a Foreign land she nevr heard of before.

Taking place before harmony (between hearths warming and the alicorn's final battle against discord)

As twilight reads this tale she discovers that a number of her friends might have had a lineage beginning in Marengarde and they all fought alongside each other in a conflict against the griffon empire

You’ll laugh you’ll cry you may even reflect a little on the similarity and differences between your favorite characters and their distant ancestors

(Rest assured pinkie-pie's ancestor will find multiple ways to break the fourth wall)