What seemed like a casual visit to Canterlot changes drastically when Twilight visits the library and finds a book she's never seen before. Curious, she "borrows" it, and takes it back to Ponyville, for some light reading. It seems like a normal book, full of random magic spells. A cryptic message sends the mane six on a crazy adventure to another world, where they run into ponies with their personalities. And it only gets crazier.