Starswirl has invented the perfect time travel spell. With it, he can visit anytime, anyplace throughout all of history. Celestia, deciding that his new spell is a terrible idea, tries to prevent him from using it before he does something ridiculous. Unfortunately, the first thing he decides to mess with is all of history. After all, nothing can go wrong when you're fixing all of your forefathers' mistakes.
Enormous thanks goes to my editor, AlicornPriest. Cover art was done by the amazing xoxPinkiePiexox