When Luna gifts Twilight the town of Ponyville and its surrounding countryside as her demesne she's initially confused. Then, after double checking her dictionary, more than a little concerned.
Twilight finally perfects the Wing Casting spell, perfecting it down to the most trivial detail. Her friends are more than thrilled to hear and experience the fruits of her labor. All of her friends, except for Rainbow Dash.
With her new apprenticeship under Nightmare Moon, Empress of Equestria and Queen of the Eternal Night, the orphan filly Twilight Sparkle plunges head-first into the conspiracies, secrets and intrigues of the Empire.