A/N: Hi all! This is my first fanfic i've ever written for undertale! Please be nice! :) I'm still trying to get into the swing of the characters...I'm struggling a lot with Papyrus and Gaster so if anyone has any advice please say! I've already submitted 2 chapters on AO3 so I'm putting both up here at once.
For reference, in this timeline everyone made it to the surface and Gaster is a thing (or is he...?) who has the personality similar to his Glitchtale (if you've seen that) counterpart, so he's not mad or evil/insane, but still acts like a dick and is v moody/serious, and is creator/father of Sans + Papyrus.
Be warned it's a heavy story as I'm an angsty person and this is my emotional outlet lol.
Prologue
It sounds like a waterfall.
Or perhaps indeed, waterfall itself. The familiar sound of gentle gushing water, filling his ears and drowning out the noise of everything else around him.
Except it was not gentle, and the gushing was more like white noise drenching of water, hissing and screaming high pitched in his ears. It was filling his lungs now, leaving him breathless and coughing and choking and gasping—this was definitely not waterfall anymore. He suddenly realised he was awake, but his eyelids weighed heavy. Above all the hissing noises and breathlessness he opened his eyes, and reality set in.
Blackness bled around the edges of his vision, only just about being able to vaguely make out the shapes of the creatures in front of—no, above him. He was lying down.
He noticed the hissing was starting to fade, and instead there was a shrill bleeping sound beginning to fade in—an alarm? Was he still in bed? Perhaps he was late for work.
But the creatures above him began to form into recognisable shapes—alphys, papyrus, toriel, gaster, frisk—
Wait.
He felt himself grow cold. Without thinking, he tried to open his mouth to speak.
"g-" choking, he gasped and shut his eyes.
What the hell is going on?
"Do not try to speak," a voice said, familiar but one he hasn't heard for oh so long.
"I do not think he can hear you. He still looks rather dazed," a delicate voice said, and he pinned it as Toriel.
"He can hear you! Look! You've! Made him panic!"
Pap was here. He couldn't see him like this, his bro was innocent and naïve and perhaps a little bit of a bonehead. Surely this was just a weird nightmare, those were pretty common now.
Sans tried to open his eyes again.
Yet there it was, the impossible figure.
"gaster," he breathed, voice barely audible over the shrill beeping sound that screamed in his ears, "get pap out," he continued, refusing to look at his brother's face in fear of what expression was currently etched on it.
"I told you not to speak, Sans," the voice said, over some complaining sounds originating from papyrus.
He rolled his head to the side, seeing Frisk leading Papyrus out of…wherever they were. Where exactly were they?
The yellow figure of alphys swam into his vision again, and only now he noticed her holding something over his chest. The reptile seemed to notice and attempted to speak to him.
"Umm…j-just try to stay calm! I have everything under control!"
Sans stared at her blearily. Stay calm? He could hardly stay awake. Out of curiosity, he attempted to call upon his magic, perhaps they could provide some answers.
Nothing. Hmm. Gaster Blasters.
His mind jumped back to Gaster.
"you died." he said blankly, vision beginning to swim. The focus on the creatures surrounding him was fading again.
Somehow, there was an etch of visible concern upon the old man's face.
"Sans, I have been around for…" he stopped himself, watching Sans' face for a while before deciding to instead say, "Do you know what has happened to you?"
He shook his head, "been tryin' to…figure that out myself…y'know," the sentence seemed to have zapped the energy from him, as the black edges of his vision crawled closer to the centre, his eyelids growing impossibly heavy again.
An alarmed voice rang through his ears, "N-no no no! S-stay awake! You gotta stay awake! Don't…don't fall asleep, okay…?"
Gaster's face greeted the last inkling of his vision.
"The timeline, Sans, what has happened to it?"
Unable to think, the younger skeleton just groaned as he shut his eyes while the blackness took over.
"Answer me, Sans, something has gone wrong with the timeline. You need to stay awake."
The rest of the almost panicked rambling was drowned out by the noise returning to his ears, the energy sapped from his body as he suddenly became limp, deciding whatever it was would be best to deal with another day. Right now, it was time for another nap…
2 days ago
The ache in his side wouldn't be so much of a problem if he wasn't trying to understand what the hell was happening with the timelines. Jumping back and forth, stopping and starting, restarting—this was almost normal at this point.
But there was something else. Almost as if things were happening that shouldn't be, people were here that shouldn't be, things that didn't belong here. But it was the same timeline.
Sans growled inwardly and slammed another human book on the art of science shut, wincing as it twinged his side. Humans were so ridiculous. They had no clue alternate timelines existed other than something they had conjured up as 'science fiction'.
"What exactly are you looking for, Sans?" the much older skeleton said behind him, shuffling through books in a considerably calmer state than Sans was.
"dunno. guess I assumed being on the surface and all we'd have actually learned something from these humans," he retorted, eying yet another book, "i guessed wrong."
Gaster huffed, "I'm quite sure we have learned a considerable amount, just perhaps not in the way you were hoping," he paused, staring closer at the book page, "in fact, this is new."
Sans glanced up towards him and blinked, "you found something?"
"A new discovery," Gaster began, bringing said book towards Sans, who was now visibly holding his side. Gaster eyed him wearily.
Sans took the book from him and ignored the glares at his side, speed reading through the page. The old man was probably just trying to get his hopes—
Ah.
"so, they found something we didn't," he retorted.
There has been multiple instances in which several timelines have been seen to have pieces in one other timeline, taking elements from other timelines and using them in a current one, even though these contributing timelines have not failed and still coexist somehow.
"well, that's new," Sans agreed, slamming the book shut and tucking it under his arm—audibly hissing and switching arms, "welp, i'm gonna bone up on my facts, cya."
Gaster's eyes narrowed, "Something the matter, Sans?"
He snorted, "nah, probably just pulled a funny bone," he began to head out the door, needing to research on his own…and also to get away from Gaster's staring. Or perhaps Gaster himself. Something felt…off.
"Very well. I'll be here if you find anything new," he offered, deciding whatever predicament he was in wasn't more important than this incredibly important timeline research. He just hoped he wouldn't regret it.
Back at the skelebros house, Sans' temper was steadily rising through the pain in his side and the constant ramblings from his brother about nothing other than spaghetti.
And having insisted on using a human oven, as it would, in Papyrus' words, 'appeal to the humans better nature if spaghetti came from their own oven', Sans had to stand and watch him each and every time to ensure he didn't set the thing on fire.
"Did you know humans have 350 different types of pasta!?" Papyrus was yelling, while simultaneously flipping spaghetti in the air as if it was a pancake. Unfortunately, it was also splattering the walls in the process.
"yeah that's real interesting pap," Sans retorted, glancing down at the book under his arm.
"Three! Hundred! And! Fifty! So many! New Pastas!"
Sans walked over to an empty cabinet and plonked the book down heavily.
"yup. can't wait to see what you make outta that, bro," he mindlessly said, speed-reading through this book.
Something felt off. He couldn't put a bony finger on it, but he knew it was to do with the timelines. He just couldn't figure out what.
"Sans…where did you put the flour?" Papyrus interrupted his thoughts.
The other skeleton sighed, wincing and nearly falling forward at the rush of pain in his side, "it's where you left it, bro, i ain't touched it."
Papyrus, in his own little world, didn't notice. "I've been thinking, I should make that 400 pastas. I want to learn 400 recipes for making pasta from scratch!"
"cool," Sans flipped the page. There has been no evidence that monsterkind can manipulate the timeline. Yup. Well, except Flowey, I guess.
"I could…how will I do that…?" Pap seemed suddenly unsure of himself, "I could…merge…the pastas…?"
Sans' eyes went wide in realisation, stepping back and gritting his teeth.
"shit"
"SANS!" Papyrus bellowed, causing him to wince, "No swearing in our household!" but he paused, and said almost sadly, "Does my cooking really…worry you, that much?"
Sans shook his head, attempting to close the book but hissed through gritted teeth, an agonising wave of pain hitting his side, sending him reeling and clutching onto the counter.
Papyrus noticed this time, "Sans! What's the matter with you!?" apart from the obvious signs of pain, his brother was showing an odd amount of frustration and tension, something that he was would so rarely portray around him.
Sans growled in frustration, desperate to read into this more. Papyrus had mentioned merging pasta, and this triggered a realisation. A turning point.
But right now, he was in agony and couldn't move.
"s'not your cooking, paps," he hissed, suddenly unable to hide an audible cry of anguish as his ribcage suddenly felt like someone had torn into it with a knife.
"I'm not worried about that right now, brother, you don't look very well," Papyrus stepped closer, eying his brother tentatively, trying to figure out what to do. "Uh….do I call a doctor…?"
Sans inhaled sharply, "no, no, m' fine, just…gimme a sec," he waited for the feeling to pass, whatever it was. Whatever was happening.
But it didn't pass. With every moment, the pain sent his vision spinning, blurring and swimming. His instincts immediately told him to sit down.
With one hand on the cabinet, Sans stumbled forward and looked for anything that looked remotely like it could be sat on, ideally a chair. But his sight was so blurry, he couldn't even see the shape of his brother properly.
As another rush of pain tore through him, Sans grunted and fell sideways, crashing into stack of plates and hitting a wall, before finally collapsing to the floor.
"SANS!" his brother yelled in surprise, immediately getting onto the floor and sweeping the shattered plates out the way. "What's the matter…? What do I do?"
With no reply from the smaller skeleton, Papyrus began to panic, "Uh…uhm…" he got up and raced to the phone on the wall, dialling the first person he could think of.
When there was a reply, Papyrus ran a trail of a panicked words, "G-gaster! It's—it's Sans! He's…just…fainted…?! I don't know what to—I don't know!" breathlessly, he turned around while on the phone and watched as his brother suddenly started trembling, "It's—I—he's—he's—he's—uh—yeah…yeah you're right, I know I should calm down but I can't! And now he's shaking…!? How much? I don't…know? You're coming over? Okay…" he paused to catch his breath, his mind reeling from the pure panic.
Usually when he became like this, it was always Sans that was there at an instant, but now he didn't have that…who else was there…?
He raced back over to his brother's side; however, he suddenly noticed a pool of red liquid staining his shirt, which wasn't there before. The shaking had subsided, leaving only breathless gasps coming from the skeleton, who looked entirely asleep.
Suddenly, the door to the kitchen was thrown open, with none other than Gaster storming in, looking like a skeleton on a mission.
"I have contacted Alphys, she will be arriving momentarily," Gaster knelt down beside them and tried to hide this horrid sense of dread that was causing a display of emotion; he too noticed the red stains on his shirt. "What were you doing?" he asked calmly, pulling the blue coat off of the small frame, while Papyrus just watched blankly, staring at Gaster's black coat that was taking up the majority of the immediate floor space.
"I was…we were just…well…he was reading this book…and I was…cooking…?" he gasped, "Spaghetti!" he yelled, jumping up and running to the oven, turning it off. If there was a fire, he knew Sans wouldn't be too pleased with him. Watching his older brother in such a horrible situation…his stomach churned with anxiety. Nothing this bad had ever happened in such a long…long time, especially just out of the blue.
"It is odd," Gaster remarked, pulling up the blood-stained shirt and glancing at the large jagged wound across Sans' ribcage, "as much as it pains me to say it, any other monster would have turned to dust by now. This is quite an injury."
"An injury?" Papyrus retorted thoughtfully, "You mean…someone attacked him?"
Gaster remained quiet for a second. Sans had only left their lab 20 minutes ago, and had obviously came straight here, seemingly fine as he was watching the younger skeleton make spaghetti while he just read a book. Odd, indeed.
"Perhaps, but perhaps not," he said cryptically, "The bleeding has stopped. In fact, it looks as if it has stopped for a while," how intriguing. It was bleeding heavily no less than 2 minutes ago.
At that note, there was a loud crash, before alphys came running into the room, her too looking about as panicked as papyrus, if not a little less.
"I'm here! I-I'm here!" she exclaimed, immediately locking eyes with the cesspool of blood on the floor, and the creature that still had somehow not turned to dust yet, "Uh…"
"You must measure his soul magic," Gaster said, snapping Alphys out of her thoughts. She was a scientist, not exactly a doctor of biology. But it was the closest the monsters had to a doctor that they could trust, without resorting to help from the humans, which they were not entirely comfortable with yet, especially not with someone like Sans.
"Y-yeah! Hold on," she knelt by them, pressing something that looked remarkably like a stethoscope to his chest, except for an extra block at the end which displayed the magic readings.
She gulped hard at the results, "U-uh…technically, he shouldn't be here," she said quietly, but this didn't seem to worry Gaster, "I-it's the lowest I've ever seen a monster without them being dust…"
"My thoughts exactly," Gaster agreed, "this is no normal injury. We are, perhaps, lucky, that his situation is not normal. Take him to my lab, we can heal him from there."
Alphys blinked, "B-but, he needed to go to ho—"
"I said take him to my lab," he stated louder, turning to Papyrus who had been unusually quiet, "He was talking about timelines earlier, could that have had anything to do—"
Papyrus was about to mention Sans' fascination with his book, before suddenly his red scarf was being yanked at.
"the timeline. pap. the timeline."
Papyrus glanced down at his older brother, who now seemed extremely alert, but his eyes turned to white pinpricks. If his magic was working, he was sure one of his eyes would have been blue at this point.
Gaster pressed, "What about the timeline, Sans?"
"Umm…gaster—" Alphys tried to speak.
"its merging. its merging."
"What?" Gaster was taken aback; this was something he hadn't heard before.
"timeline…merging…i…." he sucked in a breath and tried to explain, "you shouldn't…be here…" two empty eyesockets were staring at Gaster, which unnerved him a little.
"you…shouldn't…" he let out a shriek of agony, making alphys jump.
"What's wrong him him!?" Papyrus shouted a little too loudly.
Gaster glared sternly at Sans, who didn't even want him here, for some reason.
"W-we have to move him now," she prompted them, desperate to get moving, an impending sense of doom gnawing at her, panic setting in.
Unfortunately, the information stopped for Gaster, as Sans' eyes once again rolled back in his head as he started shaking again.
Papyrus was at his wits end, "He's shaking again! This is what I was saying earlier!"
Alphys inserted something that looked remarkably like the monster equivalent of a syringe into a Sans' arm, "I-it's a seizure, b-but it'll be okay," she said, hopelessness tainting her optimistic voice.
Before either of them could do anything else, Gaster almost audibly huffed in frustration and secured a tight hold of the shaking skeleton, before they both suddenly disappeared in a puff of black magic.
to be continued...