Celestia is bothered by dreams of her past, and is urged to deal with them. She sends Twilight to be trained with one of the most legendary alicorns alive who was thought to be just a myth. His incredible modesty and strength make Twilight only want to strive to become better than him. But beyond this training she must go through, she must also uncover the mysteries of her self, her teacher, and some of her closest friends.