There was a time, not so long ago, when the sun shone brightly in the skies of Equestria. Those days have long since passed, and in their place is the era of eternal night, reigned over by Nightmare Moon. All ponies serve this mistress of the night, and one such pony is Rarity, her personal hoof-maiden.

But, after a somewhat irksome visit by a time-travelling alicorn, Rarity finds her mistress more angry than usual, and soon finds herself discussing matters with another of the palace's residents, Rainbow Dash.