|| Sans POV ||

I randomly clicked the buttons on the remote as I flipped between channels. Ughh...today's gotta be boring. I can feel it in my bones. All the channels on the TV are airing the same show, Mettaton's show. All his shows would either be a cooking show, quiz show or drama show.

"SANS, HAS METTATON'S COOKING SHOW STARTED ALREADY?" Papyrus busted the door from his room as he jumped on the sofa beside me.

"yep, its actually going on for hours....in different channels." I groaned.

"FANTASTIC! I'M GLAD THAT THEY'RE AIRING A METTATON COOKING SHOW MARATHON TODAY! NOW I CAN FINALLY CATCH UP FROM THE EPISODES I MISSED!" Papyrus happily said, twirling the pasta on his plate.

He usually has training with undyne so yeah, he misses mostly metta's cooking shows but, how come he doesn't have training today? Its not the Weekend, right?

"oh? i thought you have this secret training with undyne today?" I questioned, checking the calendar if I might've mistaken.

"SHE POSTPONED IT BECAUSE DR. ALPHYS AND HER ARE GOING ON A DATE."

"uh huh, so no plans? just gonna watch a cooking show marathon?"

"INDEED, I'M CALLING THIS A DAY OFF."

"hey, which reminds me...where's dad? I thought he planned for a day off as well?"

"OH, RIGHT, HE'S AT THE LAB. CONTINUING HIS RESEARCH." Research? Maybe its about his discovery of molecular deconstruction.

(Lol, i feel like a scientist xD)

He's going on about it for days but I never got to see his experiment for myself.

"welp, I'll visit him and probably offer assistance. since i don't have all day." I reasoned, slipping on my 'ol pink slippers.

"SINCE WHEN DID YOU BECAME BUSY, SANS." Paps eyed me, setting his plate down.

"i'm always busy.....busy taking long naps and doing absolutely nothing!" I rejoiced, well kinda, maybe in  sarcasm.

"UGHH, YOUR WASTING YOUR TIME, YOU SHOULD LEARN TIME MANAGEMENT." He rolled his eyes.

"hehe, maybe some other day. i need to SPAGHETTo outta here~" I teased, closing the door behind me.

"SAAAAAANS!"

~ Tem skep ~

I pushed the creaky door open and headed directly towards the dusty stairs leading to the basement where the lab is.

The basement was actually some sort of a stock room before but then, dad constructed it as a lab ever since he worked as a royal scientist. Though he quitted being the royal scientist, he still conducted researches of his own.

Confidential files are kept within the lab but eh, I'm sort of his lab assistant now. So, I help him sometimes with his experiments.

I pulled the lab coat on by the rack just outside the double lab doors. But then, I heard breaking of glass and probably vials and beakers inside.

I heard muffled laughter and barely audible speaking. I rushed in and saw the two, Goggles blinded by ashes.

"Well done Frisk! Now our data is complete!" Dad praised. I rolled my eyes and frowned upon hearing the kid's name or so, the name she used to have before.

"Its nothing, I just read that concoction in those quantum physics books." She explained, dusting the goggles off.

"oh, so you're sneaking in my room huh." I interrupted with a stern face.

She jolted, nearly knocking a beaker beside the table. "No, I didn't. I found one of your books lying on the floor the other day and i put it back on the shelf." She cowered.

"uh huh, what else did you found? Oh wait, maybe you were finding SOMETHING, perhaps, knives?" I snickered, giving her my grim look.

"Sans! Would you please quit harassing Frisk! I find that attitude of yours unbearable." Dad reprimanded in a serious tone.

"hehe....i find living with a killer unbearable if you ask me." I snickered. By the time I knew she keeps on resetting every now and then when she killed everyone in the later timelines.

The more I get sick of it, I don't want to stay in this genocidal loop forever with only me and her knowing her heinous past.

"Its okay Dr. G I'll just leave..." She sighed, holding dad by the shoulder to prevent scolding me again.

"No, you two should know how to get along." He replied as he began pacing around the room in deep thought.

"tsk...never would i." I scoffed crossing my arms but he continued pacing. I mean, she only stayed here for 3 days its never too easy to gain my trust, especially her.

"I'll...get something in the garage. In the mean time, the two of you stay put here." He stammered. Frisk stood silently before me as her expression became bitter as if she tasted nasty medicine.

"What?!" We both exclaimed.

"Yes, I'll be back soon. I might as well take lunch." He grinned closing the door behind us.

I reached for the doors and haphazardly knocked the doors and the handle but it won't budge.

I snapped my fingers for a couple of times to summon a gaster blaster but it never came. "That door would never open, this lab prevents the practice of magic." Frisk interrupted.

"you're smarter than i thought."

"If you visit this place often with your father then you would've known." She reasoned.

"if you visit the lab for days then you're up to something." I shot back.

"looks like you poisoned dad's mind." I huffed.

"great, i'm now stuck with a killer, who knows what would happen." I said sarcastically, rolling my eyes for a moment.

"Why are you doing this to me?! What have I done wrong that makes you to despise me so much?!" She bursted as tears welled up in her eyes.

"don't ya geddit? you're the reason why WE are stuck in here. You're the reason why everyone died in the past timelines!!" I yelled as I lost my temper.

"T-t-timelines?" She asked, staring at me in pure curiosity. Don't tell me she's playing dumb again coz I won't buy her tricks this time.

"I-i don't understand...are they dreams?" She stood there, blinking for a few seconds.

I knitted my eyebrows and felt worry as the tension rises as minutes of dead silence passes by. I don't remember seeing this to happen in the past timelines. Why is she acting like this? Its different than her usual response..Is it because this timeline is....different than the others?

"Sans? Is there something wrong?"

"n-nothing."

"Then what are timelines?"

I gulped, oh no...I should've not told her about timelines because it may break the flow of the timelines. Only I should be the one to know it. She doesn't know much yet but that increases the chances of a rip to form fast.

The test tubes started rattling in a fast manner and so as the pencils on the tables. "its starting..." I mumbled. A cold wind blew and swirled around causing a black opening to emerge.

Desk lamps flickered on and off as I reached for the cabinets, shielding myself from the flying papers that was being sucked in by the black hole.

"Sans!" She called out and I pulled her behind the sofa for cover. "listen, i don't have much time to explain what's happening but i know for sure that there is one solution to all of this." I pondered, trying to think of the best solution.

"What's your plan?"

I frowned from her question but I pulled two vials inside a metal box in instant. "this, we both have to drink this." I explained.

She looked doubtful of the idea and how silly drinking an unknown chemical would stop this phenomena.

"Why do I have to trust you?" She crossed her brows.

"because....because.....gah! as if we had any other choice." I gave her the vial as I popped the stopper from mine.

"You leave me no choice." She nodded faintly.

"good, then on three. one, two, three!" I emptied the vial of bluish liquid. It tastes horrible, it tastes like how a rotten sock and cheese combined together.

Suddenly, everything stopped. Debris of the lab where flying in slow mo everywhere as if they're in space but our normal movements remains, where only floating though.

"Sans...why...did...you.. drank.. it...all!!" Frisk shouted, driving me back into reality.

"of course, the whole vial should be emptied." I reasoned in a matter of fact tone.

Her expression dimmed as she flicked her half empty vial with reddish liquid in the air towards me.

"You should've drank half of it, who knows what would happen now?! Dr. G is gonna kill me.." She groaned as I read the tiny Wingdings label on the vial.

"okay, just remain calm everything would be al-

|| Third Person's POV ||

Darkness clouded their visions as the black hole ceased dramatically and the broken debris of tables, vials and beakers where put back together again.

"Ughhh..I feel like being hammered in the head..." Frisk clutched her head as she staggered on her feet. "Sans, are you al-"  she stopped in mid sentence in shock as she saw herself before her instead of Sans.

"kid, i think the MADjic did work, hehe. i should thank you for your cooperation" Sans fluttered his eyes open and fell backwards, jolted of seeing himself before him.

"wha?.....I'm..a....human??" He stammered, examining his or should i say Frisk's human hands.

"And i'm...a s-s-skeleton??"

"AAAAAAAAAAAAAAAHHHHHHHHHHHH!" They both shouted and screamed in unison.

"i guess we swapped bodies...or so we are the other's physical appearances but our gender, traits and personality remains the same, regardless our looks." Sans frowned, checked the magenta striped sweater he's wearing, those muddy-ish brown boots and his human arms as his chocolate shoulder length hair swayed.

"You think so?!" Frisk groaned in frustration and in disgust as she checked the blue hoodie and pink slippers she's wearing as well as the skeletal arms she has.

(Imagine their physical appearance as Sans acting like Frisk and Frisk acting like Sans :3)

Suddenly footsteps from the stairs rung alerting the two. "quick! act normal!" Sans whisper shouted to Frisk.

(Lol I remembered yet another meme xD)

"INDEED FATHER, I WONDER WHEN WOULD THEY LEARN TO GET ALONG, ITS BEEN QUITE SOMETIME."

"Oh they would, in fact, I believe they are used to each other's company by now." Gaster chuckled.

"Frisk, Sans, I heard you two were screaming, is there something wrong?" Gaster asked, peeking his head through the glass door.

|| Frisk's POV ||

I was sitting on a chair face down while listening to some tunes while Frisk or should I say, Sans, was typing haphazardly on a computer.

"Strange...? Are you two alright?" Dr. G raised a brow as Papyrus followed behind.

"Yep, just hungry, I'll get some pie- I meant, ketchup! hehe" I smiled, trying to imitate Sans' lazy nature.

I walked in a wobbly manner but it feels weird coz I can't stand erect, is it because of Sans' usual posture? Ugh...as soon as the effect wears off I'll finally get back to eating pies everyday.

"Sans...? Are you sure you're feeling fine? You seem disturbed....?" I stood frozen, alarmed that I might've said something wrong.

"O-oh hehe, just tired. I need to take a nap that's all." I chuckled lightly as beads of sweat formed on my forehead.

"BUT HOW ABOUT OUR PASTA DINNER LATER?" Papyrus whined.

"I umm..uh-

"don't worry paps..er..papy, i'll make sure to wake him up, few minutes before dinner!" Sans reassured, taking cover of the tense situation as he jumped from his seat in a girly-ish manner. I exited the lab but just behind the lab doors so I'll be able to hear and peek through their conversation.

I don't act all too girly, is that what Sans sees me? Its too far from how I answer people's questions. Cmon act in character, Sans! Though, I find this funny coz I can't imagine Sans acting this way.

"VERY WELL, THANK YOU HUMAN!"

"Frisk, why don't you give Queen Toriel a visit while I finish this experiment? You've quite worked yourself too hard helping me and I'm sure she misses you dearly."

"ok? sure, i just need to dress up. Thanks! catch you guys later!" Sans waved gleefully and ran towards the door where I was and sighed in relief.

I really wanted to ask when would I get back to my body again and how are we going to act as the other in a less weird way but it seems he read my mind as he gave me a stern look as if we talked telepathically.

"N-now?"

"yes, now" he flicked his fingers but nothing came.

"I guess teleportation isn't necessary, for now..we have to walk." I said, remembering that I posses Sans' powers.

He only groaned and walked up the stairs way ahead of me.

This is bad...I really wanted to befriend Sans but it seems impossible, now that we're in this confusing situation.

~~~~~~~~~~~~~~~~
Squeeeeaaaaa! Tbh, I found writing this idea ridiculous xD and well its hard to write their swapped bodies and perspectives in line so I have to write mostly from either Sans' or Frisk's POVs .~.

Alrighty! Stay tuned for the part 2, dreamers! Boi boi!~