There is a secret held in the dungeons below Canterlot, deeper than the crystal caverns into the roots of the mountain. This secret is a creature imprisoned by the Princesses. It is a source of great knowledge, but may ultimately be a great enemy.
After suffering a major defeat, and losing almost all of her powers, Adagio separates herself from her sisters and enters the portal on her own. What she finds is a new world with new possibilities.
Lightning Dust insists that she and her twin sister, Runway Project, are nothing alike. She insists they don't get along. But will a couple of weeks stuck together with her sibling change her mind?
After the Battle of the Bands the Sirens end up leaving one of their own behind. Sonata, lost and alone in the world, returns to the place where one life ended, determined to start anew in a new world.