Many months after her loss in the Battle of the Bands and a few nights after the Starswirl festival, Adagio have finally had enough of living as a human being with no magic and decides to find a way to restore her pendent and the dark magic in it once and for all. She was also fed up with having to put up with Aria and Sonata and their antics so she abandons them and went off on her own.

But then she enters the nightmare realm and meets Bill Cipher. Together, they both join forces to destroy their enemies once and for all and takeover Canterlot City, Gravity Falls, and the rest of the world! Will the two villains succeed in their goals? Or will the heroes be able to stop them and save the world including their hometowns? Will they also save Adagio from Bill's true intentions?

After being defeated by the Rainbooms, the Dazzlings retreated back to their House. Adagio and Aria blamed Sonata for their defeat, but Sonata snapped at them and ran away in tears. Aria felt pretty bad for it and for how she treated Sonata in the past. Adagio, however, swore for revenge on not only the Rainbooms, but also on Sonata! Sonata befriends with Sunset Shimmer and her friends, who willingly forgave her, and Aria was determined to set things right with Sonata. Will she be able to do it? And will they, along with the Rainbooms, stop Adagio? Read to find out.