Something strange is happening down in the Everfree Forest, so Luna goes to investigate, but is unprepared for what, and indeed who she is going to find.
After Trixie is humiliated by Twilight, she uses a teleportation spell, hoping to get away from Ponyville. And her spell works, well, more than she expected.
Nightmare Moon beat her sister and now the night lasts forever. She couldn't be more than happy. When she finds out a fatherless foal, Nightmare Moon decides to adopt her.
Dusk Shine, archmage of Her Majesty Nightmare Moon, is assigned to aid the Lunar Inquisition in finding a terrorist known as "Ghost" where they last struck: Ponyville.
700 years have passed since the night Nightmare Moon defeated her sister Celestia and cast her to far off lands, stripping her of power. Now, the hate in the younger sister's heart has faded, and she has brought Celestia back to Equestria.