Where did Celestia disappear to, the night of the 1,000th summer sun celebration? Why didn't Nightmare Moon simply kill the mane six? What was The Nightmare willing to do in its hatred, and The Princess willing to do for her beloved little ponies?...
Celestia has a dream about Nightmare Moon, while Luna can do nothing but watch her sister's nightmare. When Celestia awakens, the two sisters talk about what they've just seen.