This story is about; Firstly, how Luna grows up, though that part is very brief. Secondly, it tells about Luna's encounter with Nightmare/Charisma, as well as the big fight between Luna/Nightmare Moon and Celestia plus the other Elements of Harmony. Thirdly it tells of how Charisma and Princess Luna become best friends while on the moon, due to the fact that they were the only two living beings up there. Fourthly it tells of Luna's return to Equestria and her reunion with her beloved subjects and family.