The Seventh Doctor's visit to his former companion, Alicorn Celestia of Equestria, becomes a trek through the mind, dreams, and soul of Princess Luna to try and avert the crisis of Nightmare Moon.

It's the Cutie Mark Crusaders vs Discord, with the fate of Ponyville and Nightmare Night on the line.

Cheerilee and Big Macintosh begin an incredible journey in this Ponyverse version of the first ever Doctor Who story, "An Unearthly Child"