What does it mean to be somepony? To truly exist? To know love, laughter, jealousy, anger; what does it mean to live? Organization XIII seeks these answers, and will do so regardless of the cost. For what does a Nopony care for the morals of a Whole Pony?

After shadowy creatures attack Ponyville, Fluttershy is discovered to be missing. After a conversation with the Princesses of Sun and Moon, the Mane Six (or Five) learn that their world is but one of many, and Fluttershy's soul; her heart; has been stolen by creatures called "The Heartless." In order to find her missing friend's Heart, Twilight Sparkle wields a powerful weapon of light, and journeys through the Equestrian Multiverse to find Fluttershy, and along the way combat the mysterious clocked ponies that seem to get in her way at every turn...

Other side of the story: Nopony