This is a crossover between MLP:FIM, and my favorite video game franchise of all time; The Myst Franchise (Specifically, Uru: Ages Beyond Myst aka Myst Online: Uru Live). The wallpaper was made for myself personally, so if it's not your favorite, I understand.
My story behind this: Twilight is doing a bit of research on extinct civilizations, when she comes across the D'ni civilization: a group of er, let's just say "earth ponies" (instead of humans, for the sake of this alternate story), whose entire culture revolved around the ability to turn books into portals, shooting you through space to any place imaginable, purely through the art of an ancient descriptive writing known as "The Art". They called them "Linking Books" Naturally, She is very intrigued by this, and teaches herself the D'ni language, and how to write linking books. She then decides to visit the underground cavern ruins of the long, lost civilization. She is surprised to find Trixie there as well. Trixie came to the ruins to learn more about the magic involved in the creation of the linking books. The two decide to put aside their past differences, and explore the underground cavern ruins together...
For more info on the Myst Franchise: [link]
For more info on Myst Online: Uru Live, and to play it online for free: [link]
made the Twilight Vector
made the Trixie Vetor