Twelve hours until the solstice—and Twilight was in the library, adjusting her telescope.
Of course, most ponies would say the solstice was already here. December 21st, that's what the wall calendar beside the door said. But precision was important to Twilight, and if you wanted to be precise, the winter solstice—the annual event in which the sun reached its lowest deviation below the celestial equator—happened at precisely 11:03 pm. Twelve hours from now. Even Twilight had to admit this added precision was meaningless for most, but anypony with an interest in astronomical observations ought to know better.
The fact that the Ponyville Telescope Society were throwing their bi-annual solstice party from 8:00 pm to 10:00 pm still rankled. How could you have a solstice party without a solstice!
There were other reasons for precision in astronomical observations, though. Princess Celestia's power was tied to the sun, just as Princess Luna's was tied to the moon. Twilight didn't know if this was common knowledge, but she'd spent enough time with each of the princesses to detect the pattern. Celestia's magic would be weaker tonight than at any other time during the year—and weakest at precisely 11:03 pm. Hopefully, nothing bad would happen.
Twilight peered through the telescope to make sure the optics were clear. A fluffy white cloud drifted through the bottom of her view, framed against the blue morning sky. She cranked a handle and the view inched further to the right.
Something nagged at Twilight. A thought, half-remembered. She stepped back from the telescope and stared ahead. She was forgetting something. What was she forgetting?
"I was calibrating the telescope for tonight," Twilight said to herself. "The constellation Equuleus is going to be especially clear this week. Okay. Calibrating the telescope. It's daytime. If it's daytime, I have to calibrate using the..."
Her eyes widened. She checked the altitude and azimuth, and peered through the telescope's eyepiece again. The last thin wisps of cloud melted away, leaving only clear blue sky.
A quiet scrabble of claws sounded behind her. "Hey, Twilight, have you seen my Power Po—"
"Spike!" Twilight spun away from the telescope, feeling her heart beat more quickly. "Do you know where my astronomical almanac is?"
"I thought you were reading it this morning. Isn't it still down in the kitchen?"
Twilight galloped past him, ignoring Spike's question.
Eight hours until the solstice—and something was wrong with the train.
"C'mon, Twilight, will you tell me why you're so worked up?"
"Not now," she hissed. "Too many ponies might hear!"
Spike flopped back on his seat, across from Twilight, and raised one eyebrow. "You do know we're stuck in the middle of nowhere, right?"
"I know! Why can't they get us moving again?"
"And the train was pretty much empty when we got on board, right?"
"Yes, but I don't see what that has to do with—"
"And you did buy us tickets for a private compartment, and told the conductor not to disturb you under any circumstances. Right?"
"I need to think, Spike. I don't have time for your little—"
"What I mean, Twilight—" Spike waggled his claws at the room around them. "—is that there isn't anypony who could hear. So why don't you calm down and tell me what you're so worried about?"
Twilight wilted under his stare, fishing her almanac out of the saddle bags on the seat beside her. She held it out to him with one hoof. "Check the solar events calendar on page eight, and then the lunar events calendar on page ninety-five. I marked them both with sticky-tabs."
Spike took the book from her and began paging through it. Twilight turned toward the window and stared out at the silhouette of Canterlot, high against the afternoon sky. "Did you ever notice the changes in Princess Celestia's magic, Spike? How she'd be more powerful—even a little taller—during the summer? Then, during the winter, she'd sleep a bit more, and sometimes she'd ask the castle servants to do things she would have done herself in the summertime, like... I don't know. When we had lessons together, she'd always brew a pot of tea for us to share. And if the lessons went long, sometimes the tea would get cold and it'd need re-heating. And she'd always re-heat it herself in the summer, but in the winter, she'd ask somepony else to do it."
"Why do you drink hot tea in the summer, is what I want to know," Spike said, staring at the book. "You're supposed to have iced tea in the summer. You don't have to keep that hot. It's not even supposed to—" Spike flipped back and forth between two pages. "Hey, that's cool! So we get a new moon on the same night as the winter solstice this year?"
"Check the times," Twilight said.
"Is this what you're worried about, Twilight? That both of them are happening... Well, that's funny. Eleven o'clock for the solstice and eleven o'clock for the new moon. Eleven oh-three, actually. That's... kinda weird, don't you think?"
"Not just weird, Spike. Uncanny. I did the calculations myself, and they're happening at exactly the same time. Exactly. To the second. No, more than that. I went out to eight decimal points, and they matched up perfectly. Something is going to happen tonight, I know it."
"What do you mean, something is going to—"
"Ugh! What's wrong with this train?" Twilight pounded a hoof against the window. "Maybe I should go talk to the engineer and see if I can help. We need to get to Canterlot, to warn the princesses."
"Don't worry, Twilight. I'm sure the train ponies will be able to sort this out in plenty of time for us to get to Canterlot."
As if on cue, the cabin suddenly lurched around them. A piercing whistle sounded from the train, and it began rumbling forward again. After a minute, the train passed inside the big tunnel that marked the start of their slow ascent up Mount Canter, and darkness swallowed them.
Four hours until the solstice—and Spike was being uncooperative.
The streets of Canterlot glowed in the early evening. Between the white light of the streetlamps and the bright and cheery shop windows, most ponies took no notice of the dark, moonless sky. A trio of businessponies wearing well-pressed suits trotted past Twilight and Spike, bickering with one another.
"C'mon, Twilight, just one more. I'm sure we'll find the new special cover variant at Axel's Comics. That was always my favorite comic shop when we lived here. They've gotta have it."
"I thought Stable Brothers was your favorite. And didn't we already check there?"
Spike kicked at a pebble lying in the street. "Yeah, well, they've really gone downhill since Mint Condition stopped working there. And he's the manager over at Axel's now, which is why we should go to Axel's."
"I thought you didn't like Mint Condition."
"Nah, he's a good guy. He's just got some pretty stupid ideas about which of the Power Ponies is the strongest."
"Anyway, we are not going to Axel's." Twilight frowned up at the castle, rising above the city.
"But it's only two streets over! It'd only take, like, half an hour max to check if they had it."
"I thought you said you were sure they'd have it."
Spike coughed. "Well, I mean, I was wrong about the last three. So I guess, no use pretending. But this is Mint Condition we're talking about! No way he didn't order the special cover variant. Anyway, we've got lots of time. And I still think you're overreacting. Coincidences happen. Sometimes I stop by Rarity's place the exact same time Sweetie Belle gets home from school. Sometimes the solstice and the new moon happen together. It's not a big deal."
"That's..." Twilight spluttered. "That's not at all the same thing, Spike! These are astronomical phenomena we're talking about. They work to precisely calculated schedules. They've been this way for thousands of years. This isn't like two ponies showing up at the same place at the same time!"
"Okay, one, I'm a dragon. Two, aren't Celestia and Luna in charge of the sun and the moon? I don't think this is as different as you're making it out to be."
"Fine! Fine! Whatever. If you want to go to your comic store, go. I'm heading to the castle so I can talk to the princesses. This is important, whether you think so or not!"
The solstice was about to happen—and nopony was taking her seriously.
"Princess, you have to do something!"
Luna took another sip of coffee. "And what would you have me do, Twilight Sparkle?"
"Wake up Celestia, for one thing! Don't you think she should know about this?" Twilight noticed she was pacing around Luna's bedroom again and forced herself to stop.
"My sister knows, Twilight Sparkle. We discussed this before you arrived. And we've known about it for a very long time. As you yourself rightly pointed out, we control the two celestial spheres in question."
"I know, I know, but you're both going to be at your weakest tonight! Aren't you worried that... I don't know, that Discord will try to steal your powers, or something? Or that the Griffon Empire might try to take advantage of the situation? Or that Nightmare Moon might try to reassert herself? Or who knows what other monster might come back, that nopony's ever heard of, and try to take over Equestria!"
Luna's expression darkened. "Twilight Sparkle, I would appreciate it if you didn't refer to my former... condition... so casually. Nightmare Moon is gone, which again I thank you for, but the fact remains that you are not being reasonable. Discord is reformed, and the griffons can hardly hope to invade Equestria during the brief seconds while my sister and I will be powerless."
"Wait, you're going to be powerless? That's so much worse! How are you not taking this seriously?"
Luna clucked her tongue. "I should not have said that. Still, my point remains. You haven't been able to name one credible threat for us to prepare for."
"What about Sombra?"
"You defeated him earlier this year."
"What about, I don't know... there was some guy named Tirek, right?"
"Tirek is safely locked in Tartarus. Celestia and I checked on him earlier this week. Precisely for this reason."
"I know! The Sirens! What about the Sirens? Or the windigoes? They're still around somewhere, right?"
"Please, Twilight Sparkle, calm yourself. I can send for some tea if you'd like." Luna's horn glowed briefly and a bell rang outside the room. "Come, sit with me. The event is nigh. Everything will be fine, as I told you."
She was pacing again. She couldn't help it. "No, it won't! It won't be fine. It's never fine. Something always happens!"
For a moment her voice hung suspended in the room, and the world seemed to hold its breath. She felt the tide of magic flex within her. Twilight turned toward Luna, her heart pounding in her chest.
Luna blinked twice and took another sip of her coffee. "There. It is done. The solstice has passed, and the new moon with it. Now our power will return, as it ever does."
Twilight galloped to the balcony and threw open the glass doors, looking out into the moonless night. "No! Something happened! I know it. I felt it! We need to be prepared!"
There was a sigh behind her, and then she heard the sound of hooves clopping across the tile floor. Luna joined her on the balcony. "There is nothing to prepare for, Twilight Sparkle. The event is over. Equestria is safe. My sister and I are safe. Sometimes, coincidences happen."
Twilight growled under her breath. "No, they don't. They just don't. Not like this. And I'm going to stay right here until I know what happened. I'm going to wait and..." She sniffled. "And..."
She could feel herself starting to cry. Why was she starting to cry? Everything seemed fine, just like Luna said. What was there for her to be upset about? She sniffled again.
"Twilight Sparkle, are you all right?"
"I'm fine, Princess. I'm just..." She stared out at the night, at the darkened countryside lying in the shadow of Mount Canter. "This isn't how it works. Something always goes wrong. And then I have to save everypony. For once, I wanted to stop it from happening. I wanted to protect everypony before there was a problem. But... But I failed."
Luna brushed a hoof through Twilight's mane. "How did you fail? You came to warn us. And now Equestria is safe. Is this not what you wanted?"
"But nothing happened!"
For a moment Twilight thought she saw a hint of a smile on Luna's face, and then it was gone.
"Yes, Twilight Sparkle, that is precisely correct."
After Twilight left, Celestia crept into the room and went to stand beside her sister on the balcony. They both stared up at the night sky in silence.
After a while, they turned away. Side by side, they walked back to Luna’s table and sat. "So did you tell her?" Celestia asked.
"Tell her what really happened?" Luna snorted, tossing her mane. "No, of course not."
A grin split Celestia’s face. “Didn’t I say she was fun to tease? I said that, right.” She turned toward the door and her horn glowed, and the bell in the hallway chimed once more.
Luna rolled her eyes. “Patience, sister. I already rang for the servants when Twilight was here. They should be along shortly.” She took another sip of her tea.