Twilight Sparkle realizes that Rainbow Dash has been keeping a secret from her ever since the Mare Do Well incident. When she goes to confront her about it, she finds out more than she bargained for. And then Twilight reveals that she's been keeping something from her friends ever since the Royal Wedding. Now everything is out there; harsh words have been spoken and a once strong friendship hangs in the balance.

"Peaceful days are coming to a close for Equestia. With the return of an old friend, The Spirits of Harmony must prepare themselves for an adventure filled with danger, love, and an ancient evil's return..." Pairings revealed in the story.

Nightmare Moon always had a backup plan if she ever were defeated; she would slowly regenerate herself and regain her power. The problem is she never expected to come back as a defenseless filly, or to return directly in front of the princesses. As punishment for her past crimes, Luna has given her a sentence far worse than being sent to the moon again. Nightmare Moon must move in with Twilight and report to Luna on the magic of friendship. She's not very happy about it.

By the way I am not trying to rip off Past Sins in any way. Nyx is NOT in this story, this will go in a completely different direction.