Contains spoilers for Season 7, Episode 10: "A Royal Problem," as it takes place the evening after the events in that episode. The episode itself serves largely as a framing device, however.

Long ago, Luna turned into a twisted, evil version of herself, and Celestia remained to watch over Equestria. Yet Celestia has wondered whether she too could turn into a "Nightmare"... and she's speculated about what she would become.

She has kept these thoughts to herself, but when Celestia and her sister witness the former’s evil counterpart, "Daybreaker," in a nightmare, Luna notes that Celestia does not seem too surprised at her own "dark" side...

The next evening, Luna asks Celestia for her thoughts on Daybreaker - and asks what exactly would turn Celestia into such a monster...

Proofread by SPark.

Princess Celestia tires of constantly being surrounded by decorum, deference, and formality, and decides to take a day off from being Princess. But visiting Ponyville incognito is harder than she expects. Will she be able to fit in and make friends without blowing her cover?

As she prepares to lift the sun to its apex, to usher in the solstice and bring the Summer Sun Celebration to its climax once more, Princess Celestia embraces the vision of the Equestrian summer that it places before her.

In the vision the summer she is birthing plays out around her, and as a happy phantom she walks through the summer stories of the lives of Twilight, Spike, the other bearers of the Elements of Harmony, their families and loved ones, and even her own sister, Luna. As she does so, she thinks on this world, her role in it...and the gift she's given it.

When the guards find a foal crying in the city streets, they bring him to Celestia's attention. Soon after, It becomes apparent he has fallen through every crack in Equestria's society. Feeling she has failed the colt, Celestia takes him into her own home.

Special thanks to my editors: ersmiller and Rinnaul and to my comrades in crazy ideas Exelzior and BionicBrony.