Twilight changes Star Swirl's time spell to travel back to the past once more. She ends up in the Pre-Equestrian era and unwittingly saves two fillies in the process. Little did she know what teaching them magic can do for the fate of Equestria.
Life is a delicate thing, only happening once and all. For Twilight, the one life she's able to unequivocally call her own has been recently turned on its head. Fortunately for her, good times and laughter never disappear at the library.