When Celestia messes up a spell big time, a new species of creatures appears in Equestria, along with these odd red and white balls. They seem to repeat their name over and over, and might turn everything upside down, and cause chaos for all.
In another usniverse, Equestria is a modern country. Luna has nothing to do, and needs some friends too. Celestia gets fed up with her intrusion on her work and her complaints of boredom, so she sends her out of the castle, and into the world.