As the railway carriage swayed through the gently-falling snow, she pondered what Princess Celestia might need help with.  She could think of nothing that she had firsthoof experience with except, perhaps, the Elements of Harmony, which had lain unused for centuries before she and her friends had defeated Nightmare Moon.  Normally she would have been a nervous wreck by the time the train arrived in Canterlot—especially since none of her friends were traveling with her, so she had only her own council to keep—but her worry was tempered by an eagerness to learn more of the magic she had felt in the Crystal Empire.  She knew it was dangerous, but as a good student of magic, knew that it also had potential power for good, if used properly.  It was not unlike the mixed nature of protective spells: she had used a force-bubble to keep the Cutie Mark Crusaders out of the library during their brief stint as yellow journalists—which was, in retrospect, rather selfish—while her brother had used the same spell in his failed attempt to protect Canterlot from the changelings.