This story is a sequel to The Rainbow's Surprise

On the day of Fluttershy and Rainbow Dash's wedding, Princess Celestia left Twilight a message saying that she should prepare herself if something happens. The next morning, Twilight awakens to find that all of Ponyville has succumb to a blinding fog. She must now travel a monster-filled town in search for her teacher and friends and try to return Ponyville back to the way it was.