A mysterious book, a forgotten story, and the return of an evil tyrant. Will the power of Love save the Kingdom of Crystal Ponies once more? Or will Shadows rule the lands.

Upon finding a book the Crystal Empire, Cadence finds out the past and fall of the evil tyrant Sombra. All seems lost when Sombra returns for the Empire, But a mysterious mare appears with knowledge that may help stop the King of Monsters. Once and for all.