Sunburst flipped another book close. No, this one doesn't help at all. He took his glasses off briefly and wipes his forehead with his hoof, clearing any potential sweat that may obscure his vision. He must find the right combination of spells, he must. Her life depends on him.
As he brought another book in front of him, a creak at the door caught his attention. From the dark room he is in, only illuminated by a couple of candles so he can read the book in front of him, he can see the vague silhouette of Princess Twilight. That's right, this is her library...
"Sunburst...? Are you still...?" Twilight yawned before she can finish her sentence.
"Yes, princess, I'm so close." The unicorn said. "I just need one final component to finish the spell."
"What kind of spell? We... tried everything I know, none of them worked." Twilight reminded, a bit of desperation is present in her voice. She approaches Sunburst, but he met her midway and halted her advance.
"I can do it... You shouldn't push yourself, princess. You're already tired from performing all those spells. Let me have my turn to help" Sunburst said.
"What about you...? It's really late... Aren't you tired as well?" Twilight yawned again.
"I'm okay, don't worry about me." Sunburst isn't the best liar, but hopefully it's enough to convince the purple alicorn. Thankfully, Twilight nods understandingly with a smile, but a look of concern is still unmistakably present.
"Don't push yourself too hard, okay? Last time that happened to me, I almost ate a candle by accident..." Twilight was about to walk away, before she looked back. "Oh, by the way, I left her to sleep, so she should be alright."
Sunburst nods the princess goodbye and returns to his work. He must finish it quickly, but he can't afford to miss anything. He's so important to her, he will never make that mistake again...
Sunburst froze as the letter he just read flutters to the floor. It's horrible, it shouldn't have happened, it can't happen. Moving as fast as he can, he boarded the next train to Ponyville, silently wishing he can teleport to faraway places to get to his destination instantly. But some unicorns are just not born with that kind of magic, something he's still bitter about himself sometimes.
It took a couple of hours before he arrives at his destination of Ponyville, in which he rushes to the place written by the letter: The Ponyville Hospital. As he enters the building, panting since he ran from the train station all the way here, he spots the sender of the letter, princess Twilight Sparkle, sitting on one of the benches, a solemn look on her face.
"Princess Twilight!" The unicorn called, much to Twilight's surprise.
"Sunburst!" The alicorn greeted. "You... got here very fast."
"I took the first train here... What happened?" He asked. Twilight doesn't seem to be eager to answer it, but she did.
"I'm not sure... She just collapsed in front of me and turned into a hacking mess, some... liquid came out from her mouth..." Twilight described. "The doctors are seeing her now in that room, but they told me we have to wait."
Sunburst held his head low, looks like there's nothing they can do for now. So for now, they sat together, and waited.
He found it.
The last piece of the spell.
Double checking everything, he is sure that the spell is completely crafted, not even a small detail is out of place. Carefully, he tried to simulate the spell by using it only halfway. Lighting his horn, he feels all the magic that gathered on the tip.
"Vinculum should give me the feeling of-- oh, there it is. Duplex will intensify the spell, just like that... If I add aeternum, I should feel a swirling magic along my horn-- oof!"
Sunburst abruptly stopped the spell. By 'feeling' the spell construct itself, he's confident that the spell would work if he decides to do the entire thing. But he knows he needs to strain himself to the limit to do it, because he's not a natural spellcaster. Judging from his ability and the time he has remaining, this will be a one-shot spell. If he fails or didn't cast it in time, the spell would lose it's usefulness to him, and all he just did would be for nothing.
Not wanting to be rude after using somepony's else library, Sunburst returns the books to their proper places in the bookshelves. He took a few deep breaths to calm himself. Inside, he knows everything comes down to this, this one spell will change everything. This is what he's been working so hard for. Taking a step towards the door, he made his way out of the library, into the halls shadowed by the darkness of night. He knows where to go despite the notorious labyrinth of rooms and hallways the castle has. He has been there himself several times to meet her...
Twilight is still on the same bench she was on, but Sunburst isn't. Several seconds ago a doctor came out of the room Twilight pointed at earlier. Before the purple alicorn can react, Sunburst said he'll be the one who'll listen to what the doctor have to say, sparing her of the task of getting up. The princess watched from afar as Sunburst and the doctor exchanged words, although she can't hear what they're saying since they're rather far away. It took a few minutes, but finally the doctor finished talking to Sunburst, and he made his way back to his seat. Twilight noted his grim expression, causing her to gulp.
"What... did the doctor say?" Twilight dared to ask. Sunburst let out a long sigh before giving her the answer.
"...Falsus Stillussi virus. She s-somehow got infected by it." Sunburst struggles to form his words. "The virus consumes her blood cells, a-and--"
"Extracts some kind of liquid that can clog her throat and windpipe." Twilight continued, seemingly familiar with the subject. "No wonder the liquid oozing from her mouth seems familiar..."
"You knew this disease?" Sunburst asked.
"Reading books does help." Twilight briefly smiled, but soon her expression changed back. "...There's no medicine that can cure all of her symptoms like any normal disease , we need to get various medicine to completely cure her, and that would take a lot while. But I heard that the virus is rather weak to magic..."
"Healing spells?" Sunburst purposed.
"Exactly." Twilight's face brightened slightly. "It's still won't be easy, but it's our only shot. Let's check what kind of spells I have in my library..."
"Wait, princess, can I talk to the doctor first? I need to ask something..."
This is it.
This is her room.
Sunburst approaches the door and gives it a gentle push. Twilight had said she had left her to sleep, so knocking the door would just--
"*Cough*... *Cough*"
Sunburst opens the door wide enough for him to enter the room. The room itself is only illuminated from the moonlight through the window, shining down on the bed, and the poor sick mare he cares the most. Sunburst noticed that her eyes are still half-open, and would cough every so often.
She can't even sleep.
Sunburst's mouth quivered. She's in a such miserable state. Since Twilight is so eager to cure her with her spells, Sunburst manages to get the doctor's permission to let her be treated at home. This way, Twilight would find the spells needed to cure her and use it on her faster. Plus, she would be more comfortable at home, where her friends can meet her easily without the restriction a hospital have. The few early 'Get well soon' presents from her friends would also mean significantly to her. But all it does is to make her comfortable, not cure her. No matter how many spells Twilight had used, or get well wishes were spoken, she's still sick, and shows no sign of improving. With his shaky hooves, Sunburst sat next to the side of the bed.
"S-Starlight..." The stallion couldn't take it, tears started flowing from his eyes. He removes his glasses to wipe them, only to be replaced with a fresh flow of more tears.
"Sunburst... *Cough* W-Why are you... *Cough* crying...?" Starlight asked, her voice just above a whisper.
Sunburst's answer is to slowly hug the sick unicorn across her chest, openly sobbing. Starlight don't really know what's going on, but she can only hug back. A tear also escapes her eyes.
"I'll... I'll never leave you a-again..." Sunburst said. "N-Never again..."
Although there are question lingering in Starlight's head, she decided to keep it away for now and embraces the hug. It calms her a bit, despite her annoying as heck cough. The hug with Sunburst is almost comfortable enough for her to fall asleep, almost. Soon, Sunburst pulls away, and looks Starlight in the eye.
"Starlight... I... I have to tell you something." Sunburst said, a few tears still lingers in his eyes.
"W-What is it? *Cough*"
"A lot of things... Your condition... and the spell I made for you..."
The chirps of the early birds made Twilight stir on her bed, which doesn't always happen if some dire situation like 'Starlight is badly sick' is happening. In which case, she just mostly fell asleep on a table from over exhaustion fro trying to solve the problem. She moaned uncomfortably, looks like she had some trouble sleeping as well. Rubbing her eyes, she decided to check on Starlight first thing in the morning. The princess got off her bed and started to walk to the hallways.
When she reaches Starlight's room, she noticed that the door is slightly open, and she can see Sunburst had fallen asleep right next to Starlight. She smiles at the heartwarming sight, before entering the room as quietly as she can. It's very quiet, the only thing she can hear is the tip toe of her hooves. When she gets closer, Twilight examined the sleeping ponies, and nudges Starlight on her cheek gently to wake her up. There's no reaction from the pink unicorn.
"Starlight... How are you doing?" She whispers to her ear.
There's still no reaction. Although she feels it'll be kinda rude, Twilight pokes Starlight's shoulder, trying to wake her up.
Her coat is cold.
A jolt of shock ran to the alicorn's spine as her pupils shrank. She immediately took Starlight's right hoof with her own. It's limp, and also cold. Twilight started to panic, and doesn't held back anymore in trying to get Starlight to wake up.
"Starlight!? Wake up!" Twilight rocks Starlight's upper body, there's still no reaction. "Starlight!!"
When yelling someone's name in front of their faces to wake them up didn't work, Twilight feared the worst. The realization feels like she just swallowed a giant chunk of ice down her throat. The princess is impressively quick to snap out of her dread, however, as she just remembered that there's another pony in the room. She turns her head to see Sunburst, who somehow didn't wake up from the ruckus she just did.
" ...S-Sunburst..! Starlight is--"
In panic, Twilight accidentally whips her hoof too hard and hits Sunburst at the cheek, causing the unicorn to fall to the floor. A scroll from inside his cloak drops to the floor, briefly catching Twilight's attention. However, the scroll is the last thing on Twilight's mind right now.
Sunburst didn't react at all.
The alicorn froze. It feels everything went silent, the chaos moments ago drowned by a that ringing noise one would hear in pure silence. It's the same silence as when she first enters the room. Something about this entire situation made Twilight's stomach turn, as she realizes that something is very wrong. It feels like an eternity, but Twilight manages to lift her hoof to check on Sunburst.
"S-Sunburst...?" Twilight nudges his shoulder. As soon her hoof made contact, that same horrible feeling returns to her, no wonder the room seems to be so quiet.
Sunburst's body is also cold.