One last letter

Actually, Twillight wanted to rehearse some new magic tricks, but then something unexpected happened. The story takes place in an alternative timeline, in which Discord was revived a thousand years earlier.

What is, if sometimes, something went an other way.
That is, what Twilight Sparkle discovers in this Story.
Here, she is accidently entered a world, whre Discord is in charge and much more is different, then she thought