They used to lived near the Crystal Empire giving their crystalline silk to the crystal ponies for they could made their wonder fabrics, just like the crystal velvet. But when King Sombra took the Crystal Empire to him and enslaved the crystal ponies, they flew away for never to return. I'm talking about the crystal butterflies.
It was then a certain white unicorn, along with her pegasus friend, will try to convince them to return, not only because it is the right thing to do, but also to made all ponies to see the most beautifull fabric their silk can do. Will Rarity and Fluttershy manage to convince the crystal butterflies to return to the Crystal Empire?

Note: This story happens during the events of Twilight and Blue Sword.