When one fateful search through the Everfree Forest leads Rarity to a secret library inhabited by the spirit of an ancient alicorn princess, she realises that it may be time to start believing in fairy tales.
With Sombra threatening pony and changeling alike, Chrysalis and Celestia begrudgingly agree to an alliance. Neither is happy at first. Yet, as they work together, they discover lasting peace, and perhaps more, is possible.