"Psst, Sky, wake up," came the voice again. This time it didn't boom, and it sounded familiar. The filly drowsily cracked open an eye and was startled to find her brother staring at her. She rubbed her face on the pillow to clear her vision.
"Bee? What do you want?" she croaked. "What time is it?"
"Sunrise isn't for another few hours yet," came the groan-inducing reply, "but I'm not sure there'll even be a sunrise," came the eye-widening admission.
"What? How can there not be a sunrise?" Sky started levering herself into a sitting position. Clearly something was perturbing her brother and she wanted in on it.
"Follow me and I'll explain," the stallion huffed as he stood up and left the bedroom. Sky could hear him trotting down the corridor at a brisk pace before turning into his study. Papers were rustled, drawers were slammed and curses were uttered.
Now thoroughly intrigued and almost half-awake, Sky slid off her bed and stretched her wings, yawning impressively. While slowly ambling down the corridor, it occurred to her that Bee was wearing his orange vest and cloak, which he normally only wore when he was studying something out-of-doors. Feeling even more intrigued, she redoubled her pace towards the study.
As she stuck her head through the door, her magic reflexively saved her face from a heavy book. She floated it gently to the floor and looked up to see Bee rifling through a bookcase, lobbing the heftiest tomes haphazardly across the room to get them out of the way.
"Bee, stop that! Why are you throwing books around? You hate it when I do that!"
"You only do it when Celestia's told you to read over some old spell book or another and you're bored after five minutes," he muttered back. His eyes lit up as they located the correct item of literature. Feeling hot and bothered after his canter back to the School, he shrugged off his cloak and vest. He searched the pockets of his purple undercoat for his vanished glasses, going as far as taking that off too in order to pat it down fully. Deciding his glasses must have fallen off unnoticed during his frenzied rummage, and were now hidden under the books and paper strewn about the room, he gave up his search and plonked himself down at the big wooden table in the middle of his study.
"Um, Bee, you know you're reading in the dark, right?" Sky reappeared in the doorway, having shambled back to her room to adorn her sleepy head with the big red bow it usually sported. Her brother hadn't realised the light being off was the main reason he was now struggling to read the book he'd been searching for. He started standing to go and turn it on but Sky shook her head and said, "Don't bother, you smashed the bulb with the books you threw around. Here," she sighed as she floated a lit candle into the study and positioned it on the table next to the book, "use that while I go find another bulb."
"No wait, I need to talk to you," Bee suddenly called out. The old book's yellowed pages kept threatening to rip as they were violently turned this way and that. "Did Celestia ever say anything about eclipses? Or spells for locating somepony you want to find?" Sky stood staring, stumped.
"Wha- eclipse? What in Equestria is an eclipse?"
"Something that used to happen, a long time ago," Bee replied. He continued under his breath, "They had to occur at least twice a year, sometimes as often as five times in one year. That's what Celestia said, so why can't I find any record of them?" It took him a few more minutes of browsing to realise that the book, and no other book in his possession, was anywhere near old enough to mention these fascinating heavenly events, absent from Equestria's skies for centuries. He rubbed his eyes in frustration, starting to feel a little tired himself now that the thrill of the chase seemed over.
"Bee? What's wrong?" Sky was finally lucid enough to cotton on to the fact that her brother was really quite anxious about something. "Why were you outside this late? What did Celestia talk to you about?" She inelegantly stuck a hoof in her eye and rubbed vigorously to dispel all remaining drowse. "And what the hay is an eclipse?"
"Right..." Bee inhaled deeply. "Sky, I don't think we have a lot of time, so listen carefully and don't interrupt because I will not be repeating myself." The filly magically dragged a stool from across the room and installed herself on it, ears up and pointing forwards. The flickering candlelight lit up her wide brown eyes. "Celestia and I sat for I don't know how long out by a stream over there somewhere," he began as he gesticulated towards one of the shuttered windows. "She told me all about her brother and sister and how... don't look so surprised, you've always believed the so-called old mare's tales about Night Mare Moon. Yes, her. She's Celestia's sister, Princess Luna, but she went a bit mad a thousand years ago so Celestia banished her to the Moon using the Elements of Harmony. Anyway... stop gawping like that, you knew the Elements were real too."
He realised that it wasn't exactly the best time of day to be flooding his little sister with stuff like this, but it was now or never.
"So basically, Luna went mad because her power over the Moon and Celestia's power over the Sun got out of balance with each other. That normally happened and they were rebalanced two or three times a year, sometimes more." He closed the old book and turned to face Sky directly. "But to balance those huge powers, something called an eclipse had to happen. In the middle of the day, the Moon would rise and go in front of the Sun. How much of the Sun was covered depended on how badly the imbalance needed to be corrected. Sometimes the Moon just covered a small bit, making it look like somepony had taken a bite out of the Sun." He leaned forward dramatically, causing Sky to tense up. "Sometimes, the Moon covered the whole of the Sun, making it look like a blazing ring of fire in the sky, and the day would go dark as night." He straightened up again. "Eclipses normally lasted less than five minutes, but could be as long as seven and a half minutes. In any case they weren't really that long or frequent, meaning the pony responsible for them didn't need to do his job that often."
"Celestia and Luna's brother?" asked Sky quietly. Bee nodded.
"Prince Temporal. His power was necessary to bring the Sun and Moon together and to rebalance the powers of his sisters." Bee scratched his chin. "Celestia didn't say much about what happened to Temporal, but he felt underappreciated and worthless due to only being needed at most five times a year, for at most seven and a half minutes at once." Bee dropped his scratching hoof into his lap as he blankly gazed at the wall. "He didn't realise how important he really was. Without his eclipses to fix the imbalances between his sisters' powers, the problem got so bad that when Luna eventually started to feel underappreciated for her work as well, her anger was able to corrupt her entirely."
"Night Mare Moon," Sky whispered in awe. "So, why did he leave and stop eclipsing?"
"He didn't leave. He was banished." Sky gasped. "Celestia and Luna worked together to imprison him in a ring of mountains somewhere. He had become corrupted in his own way, never helping to look after Equestria except for those few fleeting moments when his sisters requested an eclipse. He went a bit mad, like Luna would do much later on, and had to be stopped. I don't know what he was doing, or threatening to do, but it was obviously quite serious." Bee eased off his stool and walked to the nearest window. He opened the shutters and moonlight bathed his concerned face, which grew more concerned as he saw how late it was getting. "I think he just got fed up with being so uninvolved with Equestria on a day-to-day basis that, in his corrupted state, he figured a good way of becoming more involved would be to explore the darker sides to magic."
"But why is all of this so important right now, tonight?" Bee considered his response carefully.
"Because after a thousand years of Luna's power being absent from the world, the prison that both the alicorn sisters put Temporal in has begun to fail. He's on the verge of escaping, and I think Celestia will need our help to stop him."