In the twelfth century, a letter started circulating around medieval courts. This letter was from Prester John, the ruler of a utopian Christian nation with utopian societies and perpetual miracles. It was one of the first fantasies about stepping through a special passage to a magical land.
Catherynne M. Valente's new novel, Habitation of the Blessed, is about a mystical figure named Prester John. Here, Valente explains the book's premise with action figures. It's the best lesson in Medieval Christian metaphysics you'll ever get on YouTube.