Celestia and Luna have separated do to false info given by ponies who they respect, and in the process has put Equestria in an everlasting war. The Elements of Harmony and their bearers have disappeared and the Crystal Empire has declared that they shall not side with the Celestial Union or the Lunar Republic. Equestria has split into two, each half fighting for reasons that are lies.
Blue Moon, Princess Luna's pupil before the Separation, has been in the Lunar Republic since it was established. Her two best friends, Scootaloo and Rumble, have been with her through thick and thin…and she has done the same for them.
But then, Blue finds Star Swirl the Bearded's original spell book, the one that was supposedly lost centuries ago. She becomes connected to it, Blood Bonded. The book gives her and her crew a mission, a mission to stop the feud and ride Equestria of the shadows that created Nightmare Moon and King Sombra. Through vicious fights and secrets that were never meant to touch the light, Blue and her squad find the shadows and know how to stop them. But to do so…Blue must face the past.

A place where the secrets could deny her feelings or even a life.