Equestria is near its end, and the end will cease the eternal lives of its two remaining princesses.

Luna gives her life for the sake of her beloved sister.

After helping Adagio through her pain and guilt from past events, Sunset has something planned for her.

After the defeat of the Tantabus, Celestia finds out what it was and why it was created...and it devastates her to no end.

It's the 990-year anniversary of Luna's banishment, and Celestia has been taking it far too well for far too long.