Twilight was in her room, reading about refraction from one book while levitating another, a more general one about physics. She was greatly annoyed when rapid knocking from her door interrupted her train of thought.
“Yes, yes, come in.”
She kept looking at the book, trying to remember where she'd been, and only cast a sideways glance at the guardspony who'd come into her room.
“Princess Twilight? I bring a message from Princess Luna: 'Code Nova'”
The book made a loud thump as it fell to the floor. Twilight stared straight ahead without seeing anything, completely frozen in place. It took a full second for her to remember to breathe, and another before she slowly turned to look at the guard with wide eyes.
“Did you just... Did you say 'Code Nova?'”
Code Nova. It meant something had happened to Princess Celestia and she was unable to fulfill her duties.
“Uh... Y-yes? Yes, that's what Princess Luna told me to tell you.”
But what could it be? Should she call her friends? Had Chrysalis returned or had there been some other kind of a disaster? But Luna had sent the guard, and he didn't look distressed, so had it been something that only affected Celestia? She realized she'd left her mouth hanging open while staring at the guard, and quickly took a more regal stance.
“Thank you.”
She closed her eyes to help focus her mind for a spell, then felt a little stupid and opened them again.
“Where was she when she gave you the order?”
Her magic crackled in the air as it punched a hole through space and transported her into the throne room. Luna was there, standing between two pillars near one of the stained glass windows. The captain of the guard was with her, holding his helmet to his chest with one hoof.
“Twilight, good that you're here.”
Luna was unfazed by her sudden appearance. Both her and the captain looked at Twilight with serious expressions on their faces.
“Princess Luna! What's going on? What's happened to Celestia? Is she going to be okay? Why did you-”
“Twilight.”
Her voice was deep and assertive.
“My sister is not currently in danger, and I am doing my best to find out what happened. I was hoping you could help me; can I trust you with a task or are you too distressed to be of any help?”
Twilight looked at her own hooves and the polished floor beneath them for a bit, then back at her.
“I'm sorry. I'll help you any way I can, I promise.”
“Good.”
Luna flashed a smile at her, but did not manage to hide the concern in her eyes.
“Could you go talk to Silver Spear, he was with my sister when it happened and was the one to inform me of it. He should have had time to calm down by now.”
She turned her head towards the stallion next to her.
“Captain, I trust you can show Twilight where to find him. You will find me in her room with the doctors if something comes up.”
Twilight banged her hoof on the door the captain of the guard told her about. It led to one of the break rooms for the castle's staff. It and the corridor it was in were only remarkable in how they lacked posh finishing touches like gilded doorknobs most of the castle had. She soon heard sounds of somepony moving from within, and the door was opened by a wide-eyed gray unicorn who had his ears put back.
“Hi! Princess Luna sent me to check on you, are you doing okay?”
Silver Spear didn't quite meet her eyes, opting to look at the base of her horn instead.
“Yeah, I guess, I mean, no, but... You want to know what happened, don't you?”
Had her overly wide grin of a smile really been that bad?
“Uh. Yeah.”
The unicorn opened the door wider and stepped out of the way, finally looking her in the eyes as she passed by.
The only thing keeping silence from taking over were the high-pitched dings as Twilight stirred the tea in her cup.
“I thought it was a little weird, but she told me to follow her up to the tower and then had me stand guard at the door to make sure nopony would go in.”
Silver took a sip from his cup and gently placed it back on the table between them, barely making a sound.
“Of course, I did as she told me to. They talked for good a while, maybe half an hour or a bit more – I'm not sure about what, I couldn't make out what they were saying.”
His eyes followed Twilight's spoon as she lifted it out of the cup.
“I stopped paying attention to them at some point, so I'm not really sure what happened from then on before the alien suddenly yelled 'No, I can't- Get away!'”
He put his elbows on the table and held his head between his forehooves.
“He sounded terrified and panicky, so I slammed open the door and...”
His eyes glazed over as he fell silent. Twilight waited patiently, blowing at her tea to cool it down before taking a sip.
“I saw it. There was a tiny pinprick of utter darkness in the middle of the room, and it was drawing everything towards it. I saw, I saw a strand of gold, like a thread, flow from Princess Celestia's horn into the... the thing and then there was a bright flash that blinded me.”
Twilight nodded at him as he looked at her, hoping he'd continue despite how his voice wavered.
“When I could see again, she was lying on the floor. I tried to wake her up, but I couldn't, so I ran to get Princess Luna.”
A somber-looking Luna sat next to Celestia's bed, her head bowed so her horn was nearly level with the floor. She did not turn to look at Twilight as she walked in, only swiveling an ear towards her.
“What did he say?”
Her voice was quiet and tone low, like she was dead tired.
“Not that much.”
Twilight recounted what she'd heard. The tip of Luna's horn gradually rose as she listened until it was pointing almost straight up.
“I see.” Her voice had regained a bit of its color. “I was told there was nothing wrong with her, as far as the doctor could tell. She's just... not here.”
She finally craned her neck and looked at Twilight. There were dark shadow beneath her eyes but her expression was otherwise neutral.
“So... what should we do now? If she or some part of her is in the alien's world, what can we do bring her back? I mean, he tried to explain how his device worked but I have no idea how to replicate any of that – or if it is even possible.”
Luna closed her eyes and let out a sigh.
“I don't know, Twilight. I don't know.”
The guard at the base of the tower where Anonymous' room was clipped a forehoof to the rim of his helmet and stepped to the side as Twilight approached him. She was nearly certain she wouldn't find out anything important up there as she laid a hoof on the first of many steps, but Luna had asked that she'd go take a look. She hadn't dared to turn her down, not when she was so stricken by what had happened to Celestia. It wasn't all that apparent, but Luna hid her emotions in much the same way as her sister did, and Twilight had learned to glimpse past the facade. She was afraid. Confused, and afraid. Afraid of being alone again. Afraid that the rift between worlds had closed forever, trapping her sibling on the other side.
Twilight knew what it was immediately. The surface of revolution of 1/x. Mathematically perfect no matter which direction she looked from. She slid a hoof on the surface of the anomaly, feeling its unreal smoothness. Even the seams between the floor tiles it was made of were completely leveled out. She took a step back and closed her eyes, feeling the swirl of magic in the room before trying to force it into order. Her eyes moved behind closed eyelids as she recalled the makings of a spell and willed it into existence. The swirl turned into a raging maelstrom, strong enough to cause the air in the room to move with it and turn into a deafening gale. She felt her mane whipping the back of her neck as she spread her hooves a bit wider. Leaning into the wind to stay upright, she reached out with three feelers that sprouted from her horn, each made of pure magic. Anomalous. Disrupted. Twisted. Torn. Bent and broken. She touched upon the very fabric of reality, and found it damaged. In the very middle of the room, right above the revolution surface, one of her feelers found a tiny pinprick of a hole.
A greenish light shone through closed curtains, leaving the room too dark to see color or make out the writing on the backs of the books in the bookshelf. A mess of thin cables crisscrossed on the floor, all leading to or from an empty spot in the middle of the room. The bed in the corner of the room was unmade and there was a small pile of papers on top of it. There were even more papers on the desk, along with a single screen and a keyboard. The chair-
Her forehooves gave out and she collapsed onto the floor. A dull thumping pain filled her head, and she felt her stomach contract. She barely managed to hold on to her dinner, lying on the cool stone of the floor while gasping for air with her eyes shut. Shakily pushing herself off the floor, she cracked open her eyes to look at the destruction her spell had caused – only to see that the room was precisely as it had been. The curtains were still drawn, the covers of the bed were just as she remembered them and the inexplicably perfect shape was still in the middle of the room. Had she imagined it? The storm her magic had created? She cast another, simpler spell and reached out with a magical feeler again, but found nothing.
“...but when I tried again I couldn't find anything. I'm not even sure if I only imagined it all and there was never anything to be found.”
Princess Luna nodded in acknowledgment and set a hoof on the throne's hoofrest.
“It is not like you to doubt your magic, Twilight. Is there some reason why it couldn't have happened?”
“Well, it's...” Twilight thought of the unruffled sheets and curtains, having to admit that they weren't solid evidence. “...it's just the feeling I got. But you're right, it's better to assume it did happen.”
The corners of Luna's mouth curled upwards as a smile took over her face.
“Then that gives us something to work with. I believe sister's school would be a good place to start asking about similar phenomena, they should at least be able to tell which books you should study.”
The night shift had taken over and the moon was high in the star-speckled sky when Twilight returned to the castle. Tiredness pressed on her mind like a heavy blanket as she wandered through the quiet corridors. She knocked twice on the door to Celestia's room before pushing it open and going in. Luna was sitting beside her sister, holding her hoof, and was looking at Twilight when she opened the door. There was sadness in her eyes but the corners of her mouth were upturned. Twilight cast her gaze down at her own hooves in answer to the unasked question.
“They suggested a few books for me to read.” Her voice was hoarse and her words slurred. “I'll take a look at them the first thing tomorrow. I'm afraid I'd fall asleep if I did it now.”
Luna said nothing. She let go of her sister's hoof, stood up, and walked past Twilight and out of the room, her face downcast the entire way.
Twilight groaned as she woke up and slowly peeled her cheek off the page it had got glued on. She rubbed her eyes with a hoof and looked upwards to see sunlight streaming in through the windows near the ceiling, illuminating the upper parts of the bookshelves around her. Her stomach grumbled and reminded her that she hadn't eaten since last evening. She shook the worst of the sleepiness out of her head and took a few shaky steps towards the dining room.
The food-laden tray did not last long under Twilight's ravenous assault. The bustle of the lunchtime dining room felt weird after a full day in the quiet of the library, but she did not let it distract her from stuffing herself with food.
She stopped herself just short of touching the door when she heard Luna's voice.
“I asked them to arrange the decorations just the way you like them. You know, with yellow roses and red tulips.”
Should she come back later to give her the lack of news?
“Or do you think I should have gone with what I'd like? I think I'd like heather... Or bluebells. Maybe both.”
Twilight pushed away the sentimentality that had crept into her and tapped three heavy knocks on the door.
“Come in.”
She edged into the room after opening the door just enough for her to fit through. Her wings brushed against both the door and the frame. Luna was once again sitting beside her sister's bed while holding one of the white hooves between her dark blue ones. The shadows beneath her eyes had grown long and dark and the mascara she wore had become smudged near the corners of her eyes.
“Hi Princess Luna. How are you doing?”
Twilight tried a friendly smile as Luna's gaze fell to the floor between them.
“I am fine, Twilight. As fine as I can be while trying to keep Equestria running without neglecting my own duties.” She fell silent for a second and looked back up at Twilight. “Did you find out anything?”
“Well...” She rubbed the back of her head with a hoof. “There's still a few books I haven't checked.”
Luna let her head fall onto the bed and let out a long, drawn-out sigh.
Twilight returned to Canterlot two days later. She'd stopped by Ponyville to make sure Spike was fine and she and Starlight had then gone to see Sunburst to ask if he had any ideas. He did, but none of them worked. The only good news she brought with her as she stepped off the evening train in Canterlot Station was that Shining Armor had promised to come and help them. He'd said he'd take the first morning train. She trotted through the main doors and onto the busy street, then glanced upwards. The moon hung alone in the sky, just like it had last night, a solitary light in the starless void.
“So, how did it go?”
There was a glimmer of hope in Luna's voice and the smile on her face seemed genuine. The thought of answering wrenched Twilight's heart and she couldn't meet her eyes, choosing to look at one of the throne room's pillars instead.
“Well, he said he has a few ideas he could still try once he's had time to look up a few things...”
She heard Luna's hooves tread on the floor and saw her turn around with her head hanging low. Her lower lip was trembling and there were spots of dampness forming in the corners of her eyes.
“I see.”
The tone of her voice was low and monotone and lacked any signs of hopefulness.
“But my brother said he'd come help us tomorrow morning!”
Twilight tried to keep her voice full of cheer, but seeing Luna like that made it difficult.
“Thank you, Twilight. I'm sure he'll be able to help us.”
She could only listen to the slow clops of shod hooves as Luna headed out of the room. She wished to help, or at least console, but didn't know how.
The pancakes had been her idea.
“Look sister, isn't it glorious?”
She watched as Luna floated one of them, decorated with fruit, berries and whipped cream in the shape of a smiley face, in front of Celestia's unknowing face.
“They're so delicious, I made them with Twilight and we even added that little extra bit of sugar you always want in them.”
The overtly cheery tone of her voice made it even worse. Twilight had to squeeze shut her eyes as she heard the clinking of the knife on the platter as Luna cut a piece off the stack.
“Mmh, so good.”
Her voice was muffled by the bit of pancake in her mouth. Twilight dared herself to look again. She'd set the plate on her sister's nightstand and was chewing on one of the pieces she'd cut off, with the fork floating next to her horn.
“Are you sure you don't want any?”
The platter rose off the stand and floated over Celestia's body. Luna had a wide smile on her face but there was a lot off about it. Her eyes were watery, her teeth peeked from between her lips and she had a twitch in one eye.
“Here, let me help you with it...”
Clink, clank. The knife cut through the pile again and the fork skewered one of the pieces.
“Open wide!”
Celestia did not move in the slightest.
“N-no? Well, how about we make another one of those smiley faces? That's your favorite part, isn't it?”
Twilight drew breath, meaning to tell her to stop, but no words came to her. She couldn't think of anything to say, and only watched as Luna scooped off the topmost of the pancakes and floated over the bowl of whipped cream.
Luna let go of her sister's limp hoof, which she had used to press blueberries into the whipped cream, as the plates and bowls and cutlery crashed, clinked and shattered onto the floor around her. Her head fell onto the sheets, burying her face in the soft fabric. A sob shook her body. Twilight saw damp spots form around her eyes.
“She's... She's not coming back, is she?”