Equestria is no more. A creature of raw destruction has consumed it and not even the combined might of Celestia, Nightmare Moon and Discord could hold it at bay.
But not all is lost, in a final desperate gamble Celestia gathered six special fillies and sent them, along with the Elements of Harmony, through the Void Between Worlds. Her hope being they would find a safe home, filled with love and care, so that they may grow strong and righteous... and one day use the Elements to drive back the destroyer and restore thier shattered world.
...And so those six little ponies began the long trot Towards A Distant Dawn.