Chapter Text
Your watch read 12:34 am when you glanced down. Fuck it was late.
Three cups of chai and two of nasty University coffees kept you alert even as your work day stretched into its fifteenth hour. Your lack of caffeine addiction served you well during crunch time.
Sans had no such advantage and a pile of at least ten coffee cups spilled in the space next to you. His desk was always covered in junk but this week was especially atrocious.
You finished jotting down the latest notes. Y’all had sent the grad students and lab assistants home hours ago so you were stuck doing the menial tasks, the ones Sans insisted you normally foist onto the “gremlins”.
Closing the book, you rejoined the skeleton by the machine he was calibrating. A tedious process of checking over their code once more and configuring parameters, it was the last task before you both could switch this baby on.
Sans’ white complexion reflected the blue screen, giving him an eerie glow. He intently stared at his code, not even your footsteps breaking his concentration.
She waited for him to look up before speaking.
Sans turned to you with an even wider grin than usual.
“she’s ready as paps spaghetti”
You both stepped back to admire your handiwork. Five years, the two of you had worked tirelessly for this reality. From editing each other’s dissertations to the fundraising dinners and late lab nights, it all led up to this moment.
The machine in front of you was a plain silver with a small controller screen and a much larger display. A few mechanical buttons littered the sides, the red switch on the front tempted you.
“Should I?” You asked softly, staring at the distinct button.
“do it,” Sans answered, nodding to match his affirmation
You pressed the On button and waited with bated breath.
The sound of electricity trummed through the metal machine and to both of your hopes and dreams, the display board lit up.
Your breath caught in your throat, hands shaking as the screen populated with paths on it, paths of entire universes captured in the tiny lines on their screen.
“holy shit,” Sans said.
“We did it.”
“we fucking did it.”
There was a moment of shocked silence before you both erupted in celebration.
“WE PROVED THE MANY WORLD THEORY.”
“we’re going to win Nobel prizes!”
The two of you were jumping up and down like kids on Christmas, screaming.
All the long hours, suffering over formulas, begging for grant money, side jobs, all of it was finally worth it.
Calming down, you caught your breath, eyes glassy with excitement at the still whirring machine. Sans did the same and wore the same dazed expression the day he finally asked Willow out.
“this is a top ten gamer moment for sure.”
“Shut the fuck up,” you said with a snort.
Sans joined in, his shoulder shaking with laughter.
“I know you find me humorous, Y/N” Sans insisted, using one of his favorite puns.
“On occasion,” you teased before turning back to the screen, “What should we look at first?”
“let’s start by seeing how many other versions of you and me there are,” Sans said, typing the filters into the machine. It let out a small whirring sound before displaying their names next to a count and then a list of timelines.
“And you said it was a waste to make a nice UI,” you said as Sans excitedly flipped through the list.
“hey maybe this would have happened months ago if we didn’t need the boxes to be pretty," Sans shot back.
“And I’m sure a command line interface would go over well with modern audiences,” you added before switching topics, “Also why do I only appear in like ten and you have like 50?”
“Your parents were less likely to get together than mine?” Sans said with a shrug.
Given you and your sister used to make bets on when they’d get divorced as kids (somehow they’re still together) it was a fair assumption.
He was still looking through all the timeline ids.
“Change the view so we can see how far back your timelines split from ours,” you asked, “I guess we can look at one yours first.”
Sans shot you a grin before following the orders.
Most timelines including Sans broke off semi recently in the past, a few from the last seven years, but most came from his time under Mt. Ebott. But one timeline’s split stretched so far back they had to expand the amount of years in the view window.
You let out a low whistle, “1634”
Further back a world “split” the less alike the timelines get overtime, a domino effect changing everything from world events to who was born. The odds of Sans being born in such a radically different universe was an anomaly.
You both made eye contact and knew you had to start there.
“let’s start with the split,” Sans said, “and see what this machine is all ro-bout.”
He earned a slap on the shoulder for the pun.
Designing the ability to look into a timeline’s past along with it’s present had been the trickiest piece to figure out but essential to get the full picture. The machine would simulate on an atomic scale what that universe looked like at the split and then move through time, changing the atoms based on the alternate present using macro and atomic entanglement to fill in the gap between the two points in time. Then their integrated AI assistant read the simulated atoms and could tell them all about what’s going on globally, locally, or even find specific people.
It was glorious.
They started at the split and watched and read the digest. In this timeline a different human child than Frisk released the monsters, about four hundred years before it happened in your timeline, the split happening when the determined child took a left instead of a right.
Monsters were able to spread across the world in the following four hundred years, immigrating to other countries and you both watched in fascination as global politics took a new shape.
Magic being available changed the face of war. Rather than an arms race for the guns and bombs, anti magic technology to save human soldiers and bolster monster attacks got better but the rest of tech did not follow.
If anything, magic’s dominance in the battlefield led to the abandonment of the early rifle for 200 years until the late 1800s. However, this did not seem to curb violence. Human beings made soul protectors and spent much more time keeping up with non mechanical weapons to fight their monster contemporaries, you and Sans spent way too much time watching cowboys sword fight before continuing on your journey through time.
The world was slower with magic, the Industrial Revolution being a gradual process rather than the rapid explosion and then technological renaissance your earth went through.
“This dimension’s modern day technology is about the equivalent of the host dimensions 1920s with a few exceptions,” you read out loud from the summation as you finally reached the 21st century.
“ooh nice they developed lobotomies,” Sans pointed out on the scrolling list of exceptions.
“Terrifying,” you said, “Let’s zoom in, see how our own U S of A is doing.”
Badly, technology wasn’t the only thing trailing behind. Social justice and politics had stayed right where they were and “Corruption led to the continued relevance of gangs with average crime rates of two hundred percent compared to the host dimension,” Sans read out, “Due to prejudice against monsters drinking, the government banned everyone and prohibition continues to this day.”
You grimaced at the figures, “Really making our dimension look peaceful.”
“yeah that’s what I was gun-na say,” Sans quipped.
“Enough of the opener, I want to see the main attraction,” you teased after a healthy eye roll.
In unison you both said, “The other Sans.”
Finding individuals could be tricky. If they are important enough to make that earth’s news it was a little easier, but for the billions of normal people, sifting through all of them was a challenge. They had to scan a human or monster’s soul and take genetic samples, process the information and then read it into the machine as an input: a tedious process.
Thankfully, you and Sans had already gone through that months ago. As designers and programmers we needed test souls and genes for the searching program and well who’s better than your own?
Sans navigated to the search feature and pulled up his pre-saved profile, wiggling his bony fingers with glee before pressing enter.
“How different do you think he’s going to look?” You asked as the machine searched.
Continent located: North America
“We’re genetic twins,” Sans said, “Though unlike humans, monsters…change depending on their level of violence.”
Country: United Sta=es of Amer?ca
“How different?”
City of Residence: New York City
“There’s a couple different ways, he might be a bit sharper than I am.”
S0.l Lo9aIed. Imagiiinfng N))))))))000.
“What do you mean by-“
You were cut off by an increased whirring from your machine, your skin tingling at the energy it exuded. The screen was a bright white and you both watched in trepidation for the image to render.
Instead the white of the screen grew stronger, blinding you for a split second. When you could look again, the screen was no longer a screen, rather a square pool of stark white mist was in front of you.
“Sans…” you said, taking a step back from their creation, which was getting brighter with each passing second.
When you went to take another pace back, a force stopped you. And it began to pull.
Panicked, you grabbed on to the nearest lab table before yelling with more urgency, “Sans!”
Looking, you saw your partner’s lab coat whipping up as he instinctively backed away. Your panicked yell caught his attention and his head spun towards you.
The whirring got louder and the force stronger.
With a scream, your left hand lost its grip on the table’s edge and you flew into the misty doorway of nothingness as it threatened to consume you.
“hold on!”
Sans’ magic clawed at your soul, slowing you down.
You managed to grab onto the machine itself, the lip of the screen giving you just enough to hold. The force pulling you was insane, the lower half of your body was already in the void, and if it wasn’t for Sans tugging on your soul, you’d have already fully fallen through.
Sans’ trademark smile was nowhere to be found as he landed on the table you were at moments before, his eyes scanning the room looking for some solution. You knew he wouldn’t abandon you.
But that was the problem.
What if whatever clever long shot he came up with to save you just got both of you pulled through? Nobody left in this dimension who’d know what happened. No one who’d know where you were and how to get you back.
‘Willow,’ your mind went to your twin, asleep and waiting for the two of you at home to celebrate. Your eyes teared up.
One of you had to go back to her.
Using all your body strength, you pulled yourself just close enough to the power button to reach.
“Sans, you’ll come get me, right?” You shout over the din of crashing books and equipment as the laws of physics shuddered.
“yeah just one sec-“ he started, turning to you freezing when he saw where your left hand was, “Y/N don’t”
“Tell Willow I’m sorry,” you shouted.
Slamming your hand down, you managed to press the button before your arms gave out.
Sans teleported in front of the brilliant white void, reaching out.
“Y/N!”
He grabbed at the air where you once were; The last thing you saw were his empty eye sockets as his eyelights shrank to nothing, the void taking you.
**
His stupid arm was still outreached when the machine finished shutting down. After consuming his partner of five years, the portal dimmed and then vanished and Sans was left in the dark lab alone. He barely registered the noise as gravity retook control of the chaotic lab.
Sans recognized he was in shock but self awareness didn’t pull him out of his disassociation.
Nothing felt real.
They still had the bottle of champagne at home, the one Willow picked out.
It wasn’t supposed to be like this.
He pulled his left hand to his face, just staring at his long fingers. Nausea threatened to overwhelm him and he collapsed to his knees.
It happened again, but this time it was his fault.
**
Sans had just opened his newspaper when a white void opened up and scattered a fuck ton of books, paper and glass all over his kitchen. He had half a mind to teleport away, when it decided to drop a woman on his floor before rudely blinking outta existence as fast a bangtail outta the gate.
Sans had dealt with a lot of bullshit in his life. Bullshit from guys who owed him money, bullshit from WingDings, bullshit from all the fucking humans. He liked to think he was quick on his feet by this point, able to roll with the punches.
But this punch stopped him dead in his tracks.
She groaned, after gracelessly falling like a sack of bricks from his ceiling, he was surprised she was moving. The woman wore a white lab coat and the strangest garments, shapeless unflattering things. She had gotten herself sitting up and Sans’ had to admit she was a looker.
E/c eyes latching onto him, she spotted him immediately.
Her expression went from one of fear to confusion before she spoke up, “Sans?”
His name launched Sans out of the stupor he had been sitting in and he ripped the human off the ground by their soul and slammed her against the wall.
Getting up, Sans let an annoyed growl ripple out, might as well scare her for the fun of it and walked over to her pinned body.
“who the hell are you?”
**
Your heart lurched at the sudden magical control. Somehow it moved your whole being as one entity, every cell in unison. It was unsettling and your mind screamed at you to move. While your dimension’s Sans’ magic had an icy tinge to it, like jumping into a cold pool on a hot summer day, this Sans’ magic warmed you, like a fire deep in your stomach.
‘Granted he could just be a relative or an uncannily similar looking business associate,’ you observed, trying to distract yourself from the danger you were in and to slow down your pounding heart.
Clearly, if he wasn’t Sans, he knew of him. Seeing him move towards you, you were leaning to the relative theory. This monster was taller than Sans, much taller. Your Sans matched your height and only overtook your sister by a few inches, while this skeleton was at least six seven if not more by your rough estimation. His floating irises were red instead of Sans’ neutral white and his exposed teeth were sharp, one glinting gold and held in more of a snarl than a smile.
He slammed his left hand into the wall next to your head, not hard enough to damage the structure but enough to rattle it and you. He leaned over you, his bulk blocking the natural light from the abundant windows. It would be hot if you weren’t 50 percent sure he was about to kill you.
You weren’t really good at lying so you decided to tell the truth as fast as you could.
“I’mY/NandI’mascientist,well an experimental physicists, butthatdoesn’treallymatterandI’mfromadifferentdimensionandinthatdimensionmylabpartnerisSansand-“
“Whoa, slow down there toots,” the skeleton said, his voice losing its edge from early but stayed deep.
He pinched the bone above his nose hole.
“Let’s start with this Sans,’ he said.
“Yes, Sans, so the Sans in my dimension and the Sans in your dimension are two different guys completely expect for the being genetically identical, so if you have any issues with the Sans over here-“
The skeleton gave you a flat look.
“i’m Sans.”
“Oh you are! I thought you might be but I wasn’t sure and you are a lot taller and have sharper teeth.”
You were nervous rambling again.
“maybe we just have the same name,” Sans shrugged, frowning again.
“Ah, you see we saw he existed in this timeline as well and that’s why we decided to peek at it,” you answered, shrinking when he glowered at your answer.
“You were spying on me,” his voice dangerously low.
“No, not spy, more like observe, scientifically, and probably would have made fun of my Sans for being shorter,” you weakly joked, trying to get on the massive man’s good side, “I can explain everything, preferably over a cup of tea instead of pinned to the wall.”
“How do I know you won’t try anything,” he questioned, pulling back to study you suspiciously, his red eyes wide and brow bones furrowed.
“I think it’s pretty clear what would happen if I tried to fight you,” you replied, “And it’s not like I can run to anyone.”
Silence filled the kitchen and you nervously waited for him to move.
He lowered you gently, unlike your damn machine, and pulled out a chair at his wooden table.
“Alright then, sit.”
**
Sans took a long sip of his lukewarm coffee just to give himself a moment. His brain hurt, multiple dimensions, something called quackton mechanics and math that hadn’t even been invented yet. Her story was so outlandish he was almost inclined to believe her.
Almost.
She was fidgeting with the table cloth, the one Toriel made them for Rudolph Day and looked away as soon as he made eye contact. Allowing magic to flood his bones he picked up at her heart rate, high. Cortisol and adrenaline putrefied the air and Sans took a deep sniff of his coffee after releasing the magic to clear his senses.
“That was a nice story,” he said, causing the woman to jump, her e/c eyes now boring into him.
“Now here’s what going to happen,” he continued, “I’m going to make a phone call to my brothers and your going to repeat the same story start to finish, and it better be the same story toots, and then we’ll decide if your telling the truth or not.”
He grinned as her expression evolved to complete terror.
**
It took thirty minutes for Sans brothers to arrive. That gave you enough time to speculate how many brothers besides Papyrus this Sans had, and study every inch of the kitchen. You sat at a square table with two hand carved chairs with soft pillows. If all the occupants were Sans sized the table was relatively small, but it could seat your dimensions Papyrus, Sans, Willow and you easily. It was covered with a a charming white and blue table cloth with a pair of salt and pepper shakers with the craftsmanship of a child.
There were many windows and through them you could see a walled yard, it looked small and other tall homes blocked your view. The windows were framed with white lace curtains, reminiscent of the ones your grandma owned.
The kitchen was very tall with fern green walls and white appliances to match. You recognized the gas stove and ice box from history class but some of the other fixture’s purposes eluded you.
The checkered linoleum looked fresh in a way it never had in your world, clean white ground and straight tiles that had not yet been warped and morphed by the years and people’s feet.
A wooden door to the back lead outside, though you didn’t let your hopes get up. This Sans would slam you down before you could get half way to the exit.
He had left momentarily to make the call, warning you running would have dire consequences. He now sat across from you, slowly smoking a cigarette. It took everything in you not to tell him it’d stain all his nice wallpaper. He hadn’t said a word since coming back in and you didn’t feel like small talk at the moment.
You resorted to counting tiles to distract yourself from your dread when the sound of a door slamming open came from behind you.
Whipping around, you look to the closed door which hide whoever just entered the house. Though, judging by the increasing volume of the footsteps, they wouldn’t stay hidden for long.
You nearly fell out of you chair when the door slammed open.
“SANS WHATS IT ABOUT AN EMERGENCY.”
The Papyrus of this universe was also taller than his older brother, by at least two feet. Like his brother his teeth were sharpened and his body was broader, edgier than the spaghetti loving skeleton you knew. Also, unlike your fashion disaster of a friend, this monster cleaned up well. He was in a casual outfit for this society, button up white shirt matched with tawny brown suspenders and trousers and he carried a brown bowler cap in his right hand. His clothes looked ironed and dare you say even coordinated. You wondered if this Papyrus was already dating Mettaton.
“Papyrus, calm down,” a soft voice drifted from the hallway behind the tall skeleton.
Papyrus moved to side allowing a third figure to enter the kitchen. He was taller than Sans, not by too much, though he held himself at a hunch. Like his brothers, he was a skeleton and displayed the same sharp features but his mouth was … odd. Rather than having separate teeth, it was hewn from the bone like a jack o lanterns mouth. But his most startling feature was the massive gashes that sliced his left temple and right jaw.
He wore a dark trench coat and held a fedora in his left hand and a gold and black wood cane in his right. He walked with a slight limp but carried himself with a quiet confidence that sent a chill down your spine.
“I assume it has something to do with this young lady,” the third monster answered Papyrus’ question.
Sans grunt in affirmation before adding, “Always observant, huh, WD. Yes, this sister broke into our house this morning.”
The air crackled with magic at Sans' announcement and you jumped at the sensation of oil covering your skin.
“You possess no magic yourself,” WD stated, “How did you get past my security measures?”
WD’s eyes were like your Sans, white and analytical.
“By accident, with an inter-dimensional portal,” you answered, trying to clear up that you did not mean to do a B&E; at most it was a trespassing charge.
Sans got up from his seat and offered it to WD, who swiftly took it. Papyrus lit a cigarette and leaned against the wall, staring at you as he took a long draw.
You sighed, “Let me start from the beginning.”
**
“I don’t like it.”
WingDings ignored Sans as he carefully reviewed the research notes that had come through with Miss Y/N. He hadn’t done advanced mathematics and physics in a long time, like rusty cogs in his brain, the machinery was slow to move. His scars itched and he was frustrated with the snail’s pace he was going. He used to be much faster.
“And I don’t trust her at all,” Sans contined stating his case, “I’m sure if we asked around some monsters got magic who can do that. Plenty o scabs willing to work for human gangs.”
“But her clothes,” Papyrus pointed out, “I’ve never seen anyone dress like that before. Sad timeline if that’s what people wear.”
Sans chuckled at Papyrus’ last comment.
WD finally finished reading the papers, irked by his noisy brothers but he had enough information to make his judgement.
“She’s telling the truth.”
Papyrus’s cigarette almost fell out of his mouth and onto WindDing’s very expensive Persian rug. Sans narrowed his eyes at his older brother.
“At least, “ WingDings amended, “This math isn’t gibberish. It is odd, more complicated than I’ve ever seen but it’s not incorrect. I would have to see the complete papers to know for sure though.”
Sans was quiet before he answered, “Fine we won’t ice her, but I say we kick her to the curb and say Ardi Verci. If she’s telling the truth then she doesn’t have her doo hickey anymore which means she can’t break in again.”
“SANS IF SHES TELLING THE TRUTH SHE HAS NOWHERE TO GO AND NO MONEY, SHE’LL DIE, OR WORSE,” Papyrus exclaimed, indignant by his brother’s lack of gentlemanly etiquette.
Papyrus could finish a hit and on his way home help an old lady cross the street; it’s just how the kid worked.
“And if she’s lying we’re letting a snake into the base of our operations,” Sans argued back.
“If she’s lying,” WindDings interjected, “Which I don’t think she is.”
Sans was back to glaring at him. WD mentally rolled his eyelights, his younger brother could be a stubborn ass when you said he was wrong. Sans hated being wrong.
“Alright, shining knights in armor,” Sans mocked, “let’s make a deal. She can stay here, that fourth floor guest room was getting dusty and she can prove she’s telling the truth by redoing her little papers. And, if it all adds up, she’s telling the truth.”
It wouldn’t be ‘add up’ it would be ‘proving with supporting lemma’s’ but WindDings was above correcting such trivialities.
“But,” Sans put up a bony phalange, “She’s on house arrest until we know for sure. Don’t need her running off to some handler to report what we’re doing.”
“Someone will have to watch her,” WD warned, “and I’ll have to put alarms on the door for if anyone leaves at night.”
Sans shrugged, “Hey I’m still up for tossing her out.”
WindDings wondered where along the road Sans became callous. It was natural in their profession, but he was so different from the small boy WindDings first met all those years ago.
“I'M AGREEABLE TO THE TERMS AND I'M SURE UNDYNE CAN HELP,” Papyrus interjected.
Undyne was one of three people WindDings trusted would never betray him. A mix of dogged loyalty and zero interest in money made her the ideal bodyguard. She’d do well on this assignment and besides, she could use more girl friends.
“Well then, are we in agreement?”
**
They had left to go talk about you thirty minutes ago, it had to be about lunchtime here and close to 2 am back home. A wave of exhaustion hit and you laid your head down on the table but your nerves wouldn’t even let you doze. Would they kill you? The world was more violent than your own. Would it be better to die fast than to be kicked out in the street? Who could you go to that wouldn't think you were a lunatic? Last thing you needed was to be lobotomized.
You stared at the door to the dining room. It was a shined oak that gleamed in the daylight; it was thick apparently since you could not hear voices on the other side. You had considered listening at the door but the risk of them walking on you was too great. Sans didn’t need another reason to murder you.
Another ten minutes passed before the door finally opened and the three skeletons sauntered in. Sans looked annoyed, Papyrus…happy? You hope that’s what the glimmering row of teeth meant. And WD was unreadable, bony expression neutral.
“We have a proposal,” WD began, folding both his hands over his cane.
He explained your house arrest and conditional survival with your new burden of proof.
“All my research?” You asked, “It took me and my Sans two years of theoretical work to figure out how to manipulate quantum mechanics to lift back the dimension of time.”
“We’ll then you better get cracking,” Sans huffed.
Indignant, your self respect demanded you push back, “How about after a month of probation I get limited outside time with a guardian.”
Your hands were pressed together and you focused your attention of WD and Papyrus, they at least didn’t visibly dislike you.
“You’ll leave when we say you can leave or when your so-called Sans comes from the sky and saves ya,” Sans growled.
Wincing, you realized you may have made a tactical error, and turned back to the shortest brother, blood pumping at his scowl. It was eerie seeing a stranger’s distrust on a familiar face.
“We decide when you may leave the property, but you are free to use the backyard so long as you are with someone,” WD amended.
His compromise surprised you, out of all of them you expected Papyrus to stick up for you the most but this mysterious third brother was kinder than he looked.
Gracing him with a smile you answered, “I can live with that.”