It was just supposed to be a simple set up for this year's Summer Sun Celebration.
But then everything goes downhill as:
His beloved aunt and teacher has disappeared without a trace.
A nursery tale is apparently real
And five insane mares won't leave him alone long enough to undo this mess.

In hindsight he really should have just let the butler go to Ponyville instead.

After Moondancer's disaster of a birthday, Minuette comes up with a brilliant plan.
Sneak into Star Swirl the Bearded's Wing, borrow a time travel spell and use it to MAKE Twilight go to the party.
However, the return of the Mare in the Moon throws a wrench into things.