It's the autumn holidays after the return of Nightmare Moon and subsequently Princess Luna, and Sweetie and her parents have gone to a cottage on the western coast of Equestria, near Tall Tale. One night, after her parents are asleep but she herself can't fall asleep, Sweetie walks outside to look at the stars, and there she meets a very old person, with a story that is just as ancient to tell.
Background is a self-made Minecraft screenshot in the Middle-Earth dimension of the LOTR mod with the following Sweetie Belle vector edited onto it. https://www.deviantart.com/tamalesyatole/art/Sweetie-Belle-Looks-Beyond-322252611