A year has passed since the fall of the Crystal Empire. While Celestia and the rest of the ponies of Equestria appear to have moved on, Princess Luna has not. She spends her evenings banishing nightmares of her subjects, especially those of her sister. In the meantime, she struggles to fight against the Nightmist that has managed to burrow its way deep into her heart. Resentment courses through her veins, and fear of rejection threatens to consume her.

When two strange creatures arrive on Equestria in the forms of Scorpan and Tirek, Luna assumes they mean no harm...at least until ponies begin dying. Surely the Elements of Harmony will be enough to defeat the evil, but Luna begins to wonder if her heart is strong enough to wield the elements any longer.

Equestria stands upon the brink of devastation, and it's up to Celestia and Luna to save the land.

But what happens when the savior turns into an even darker enemy?