Sunset Shimmer galloped madly. She galloped flat out along the castle corridors under the puzzled look of the guards, until she skidded to a halt in front of a massive door, adorned with two huge golden sun symbols. She knocked and waited, panting. There was no answer. She knocked again, louder this time. “Please! Please respond!” she murmured to herself. “Hold on!” Celestia’s muffled voice shouted from inside. “Please your Highness!” Sunset squealed. “Let me in. It’s urgent.” A moment later, the lock clicked and the door cracked open. “Come in,” Celestia said with a tinge of resignation in her voice. Or was it exasperation? Sunset pushed the door more open and entered. She closed it behind her. Something unusual caught her attention. She squinted her eyes and sniffed discreetly. [i]What is that scent… Musk? But musk isn’t used in mares’ perfumes. Could it be that—[/i] “What is it?” Celestia growled. “Why do you disturb me at such an hour of the night? It’d better be for a good reason.” Sunset focussed back and took the room in. Celestia sat on the bed and looked sternly at her. The sheets were strangely tangled, as if they had been hastily spread over the mattress. The rest of the room was as neat as ever, though. “It’s Luna,” Sunset explained. “She… she behaves really weird. I’m concerned. I think you should act quickly or something bad’s going to happen.” Celestia sighed and her face relented. “What’s the matter?” she asked in a more mellow tone. “I couldn’t sleep and kept thinking about that botched experiment of yesterday, so I got up and decided to fetch a book in the library. And there she was, studying in a nook, her shape almost lost to darkness. I came closer to her, and when she realised I was here she slammed the book she was reading closed and put it into the drawer to hide it from me. But I had the time to catch sight of it and it was…” She shuddered. “What was that book?” Celestia asked. “It was… it was, you know, [i]that[/i] one book you’ve prohibited me to look at or even name.” “Sombra’s dark magic compendium?” “Yes,” Sunset said. “I tried to be friendly and asked how she felt. And do you know what she answered?” “Go ahead.” “She said: ‘If you continue to pry into my personal affairs, I shall certainly break your neck!’ Verbatim.” Celestia stood up and walked to Sunset. “Look,” she said, “I know her behaviour has been odd lately. It happened several times in the past. Some sort of recurrent burnout.” “Burnout?” “Yes. It’s not easy to be the princess of the night. Rising and lowering the moon. Watching over everypony’s dreams. Chasing nightmares. Gruelling tasks, big responsibilities, little reward. Sometimes she breaks down. That’s normal, and it never lasts long. Sunset, I appreciate your concern, but I assure you it’s nothing. I can take care of it. Forget about that incident, and I promise you she’ll be herself again in no time. Okay?” “Are you sure?” “I’m her sister, Sunset. Trust me. Now please,” Celestia’s horn flashed and the door hinged open, “would you mind letting me sleep? I really need it. Badly.” Sunset shuffled to the door and through it. She turned. “I apologise for disturbing you that late, your Highness—” “Celestia.” “You know I can’t call you that way, no matter how hard I try. Anyway, I was alarmed and—” “Take it easy and go to bed,” Celestia cut in. “We both need solid sleep. Good night.” “Good night!” Sunset replied. She turned left and trotted off. Celestia stood still in her room, listening to the echoes of Sunset’s hooves. When they died away at last, she exited in turn and took the opposite direction. Along deserted corridors she strode, where in eerie silence the flickering light of torches fought to dispel the smothering darkness, down several flights of seemingly endless marmoreal stairs and past colossal gates of diamond and steel, until she arrived in front of a grating which barred the entrance to a tenebrous vault. She brushed invisible runes set in the wall, and the grating slid aside. Lighting her horn, she proceeded to a round table sitting at the centre of the room, on which a mahogany box lay. She opened it and gazed thoughtfully inside at the six jewels whose facets glittered in the glow of her horn. She would need them. Any time now.