After succumbing to the demon inside of her, Twilight Sparkle is beyond the possibility of return. Midnight Sparkle breaks the barrier between Earth and Equestria, bringing the two worlds together without the natives switching forms from pony-to-human and vice versa.

Sunset Shimmer and her friends uncover six of seven magical crystals and use their power in an attempt to defeat Midnight Sparkle in their toughest battle yet. The true question, however, is how far will Sunset Shimmer go to destroy Midnight forever?