Twilight and Pinkie Pie's friends are out of Ponyville to get more citizens for the Hearth's Warming ceremony tonight. When they head outside, they've encountered a pony who's never been around like other creatures but unlike them, It's been centuries since she left on her own.
Twilight felt curious on why she's here as she invited the visitor into her castle. When she and Pinkie Pie learned who she really is, they're not only surprised, but so will Celestia and Luna when they see her.
Thanks to Daniyel099 for editing this.
https://www.fimfiction.net/user/292246/Daniyel099