In the many years after the Conversion Bureaus' shutdown, Twilight Sparkle is tasked by the Princesses with finding the last living human on Earth, Isaac Hamilton, and learning the story of his past. What she hears is a tale of loss, tragedy, joy, and the discovery of one's place in the world. But how much longer would that place last with what Twilight has to tell him?

Twilight and her five friends are transported during a botched spell, across dimensions to... Ponyville, Equestria? But not the same one that they knew. Sitting on a bench is Harpsy and Babar. The Doctoress avoids apples from an aspiring Applebuck. And in a library across town, six stallions join their forces as they try to decipher the appearance of filly look-alikes of themselves around Ponyville!