The Elements of Harmony have brought back Luna, but she can't forgive herself for what she tried to do as Nightmare Moon. She is unsure of herself, and the powers that allow her to raise and lower the Moon have not returned to her. Meanwhile, Princess Celestia is still responsible for both night and day. But with both the sisters in Equestria, the natural order of the sky is dangerously imbalanced. Each day it gets harder for Celestia to control the night.

If Luna can't get her powers back soon, the day could last forever...

Will she be able to accept her role as the Bringer of Night? Will Celestia find a way to help her get her magic back? And could a single flower really hold all the answers?