After his defeat at the hooves of the Bearers of the Elements of Harmony the stony figure of Discord was dragged far, far, far out of Ponyville where the good ponies could eventually forget the name of their tormentor...

...again.

But, it seems, as the months have passed some creature in Ponyville has not been able to put aside what had happened. Now, that creature approaches, and it seems as though he'd like a word with the immortal spirit of chaos...

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.