In the years since Luna returned from the moon, she’s always been quiet about the truth of her exile. Always keeping it to herself, hidden away. Keeping secrets. She never even told Celestia that something was up there with her.
Nightmare Moon has won. The endless night belongs now to her. Everypony is asleep, trapped inside her dreamscape. Here, and only here, will her favorite prisoners face their flaws—and perhaps reveal something about NM to herself.
In a steampunk reimagining of the universe, Twilight Sparkle finds perhaps the one pony as lonely as she is. It's rather unfortunate that they're on the moon.