Twilight Sparkle of the human world has been attending CHS for a couple of months now. For the first time in her life, things are starting to go right.

Then, one night, the sirens return, plotting revenge against the Rainbooms. Using the last of their magic in the shards of their destroyed pendants, they negatively influence Twilight under the assumption she's the same Twilight that defeated them. However, doing so unlocked an inner demon of hers thought long ago defeated: Midnight Sparkle!

With her power restored, Midnight rejoices but if she wants to keep it, she needs to ensure her friends can't use their magic against her. And she has the perfect plan for that!