Twilight Sparkle has a string of cryptic nightmares unlike she has ever had before. While she dismisses them at first, she finds that others are also being plagued by these nightmares and strange attacks. Determined to get to the bottom of this, Twilight teams up with her friends and Luna in order to find the source of these nightmares and put a stop to them.

However, when they reach that source, they are in for a shocking and terrible surprise.