Twilight and friends defeated Sombra after his return because Discord refused to fight in their place (and even hammed it up by taking a blow from the Crystal Empire's former ruler). The chaos master pushed the girls to find the magic in themselves to battle back the villain all on their own. But his 'lesson-teaching' gestures seemed extreme this time around, even for him. What is Discord hiding? What is he waiting for? And what does he want no one--neither the girls nor Luna and Celestia--to know? But Equestria's two soon-to-be-retired princesses want to understand.

A story told in several parts that will end when MLP: FIM does and we finally see what's at the end of this friendship rainbow.