Twilight Sparkle is called away to tend to Luna when she falls ill. As Luna grows sicker and Twilight more determined to help the younger princess, she begins to uncover dark secrets about the elements, the alicorns, and her own past.
After an ancient spell from Twilight goes awry, Fluttershy finds herself in a new world of powerful creatures. Whilst Fluttershy struggles in the new found world, Twilight is forced to leave Equestria to find the spell to bring her back.