The sun has stopped moving! Twilight has become an alicorn! What madness is this?
No, it's not what you're thinking. The royal sisters just decided to take a vacation, that's all! And they left Twilight Sparkle in charge! This is a test run for the young mare—one does not simply go from zero to princess in an instant, and so our dear purple pony friend needs some training first. Trollestia Style!

(In case you're wondering: Trollestia Style = give Twilight the crown and temporary wings, run off, and see how she fares on her own. Then again, this might just be an excuse for the royal sisters to go on vacation. You never really know.)

Will Twilight pass the test? Will Celestia and Luna decide she is ready to become a permanent alicorn? Uh, duh, I think we already know the answer. But Twilight doesn't!

Takes place shortly before Keep Calm and Flutter On. It's also worth mentioning that Twilight has no freaking clue how to fly.