Upside-down

'Reeeeeeeee' Frisk was saying in her little form as she was Naruto running on the conveyor belts for the 100th time now.  

"easy there pidge, you might break something before we get to the barrier." He said as he was walking with his hands behind his head. Frisk stopped at the end of the belt jumping up and down, waiting for him. He chuckled and ruffled her hair. 

"come on you excited little pet." Frisk gasped and changed to her bigger form crossing her arms. 

"EXCUSE YOU! I AM A GRYPHON YOU BASTARD! I AIN'T SOME PET!" Sans shrugged. 

"whatever floats your boat kitten." Frisk face-palmed and changed back to her small size. They kept walking. Hotland was interesting. It looked like a steam-punk type of era. Frisk watched in awe all the technology. It was clear magic and physics went well together in this place. Pipe bridges, puzzles, lava, lasers, fire all combined in one. Humans were such skillful creatures. As the two walked she could hear the steam and the cogs in the background, a wooshing sound. The same sound she used to hear when she visited her old friend.

"Mechanics and physiscs are our domain, Frisk. Engineering and mathematics...let yourself get lost in the equations....one day? you will forget all the pain. I promise you...i will be here as long as i can."

Frisk smiled fondly at the memories. But she needed to move forth now. The next puzzle got Frisk excited. Sans was sweating bullets in anxiety. 

"can't ya kiddo just...fly over...?" Frisk started jumping as steam pipes were lunching her over the lava. She pretended to almost slip and Sans used his blue magic to get her where she should be. 

"n o." He said as he teleported next to her. She chuckled. She met two humans as they walked. A really shy guy that was a total Tsundere and another guy playing with lava lamps. The two eventualy arrived to a puzzle with blue and orange lasers. Frisk looked at Sans and jumped up. He chuckled understanding the message. 

"orange, go. blue, stop. i see ya still remember." She gave him a thumbs up but just as she was about to go through her phone started ringing. It was Alphys. 

"U-uh! S-o the blue lassers...I-I mean- HI! Alphys here! S-so the blue lassers won't hurt you if you don't move! O-orange ones...um...Y-you have to be moving and they won't....um..they won't...J-just move through those ones!........Uhhh...BYE!!" And the call ended. Frisk blinked a few times and Sans snorted. Frisk casually made her way through the puzzle, with Sans close watch, who was always tense when it came to her getting hurt. he must have been a bit traumatized after she died in front of him so many times in a cold blooded way. She got to the other side and saw a switch. She pressed it and the lasers turned off letting Sans cross as well. She decided to open Monstergram to see what was happening. Apperently, To EVERYONES SURPRISE, Alphys was a huge dweeb. Frisk was a bit confused at why she posted her whole life on her status....AND Why she posted a pic of a garbage can with pink glittery fliters saying it's her...That's such an old and dumb joke. Frisk pointed at the pic and looked at Sans for answears, but he just shrugged. 

"don't look at me! it's not like i get that any more than you do!" Frisk sighed and they realized there was another puzzle. Sans face-palmed. 

"sometimes..? i hate these puzzles." Frisk giggled and her phone rang again.

"H-hi! Alphys here! S-so to open the northen door you need to s-solve the puzzles on the left and o-on the right! I-i suggest you start with the right one!...umm...BYE!!" The two jumped on the right and stepped inside a weird looking small building. It looked like a mini Las Vegas type of thing. Well...Hotland did have the hot temperature, the super star and the bilboard....Just a fancy hotel with a casino was needed and they were set. Oh waiiiittt~~ MTT Resort ring a bell? Yup...Mettaton was a Las Vegas star. She wouldn't be surprised if she will find a pole in that place with dancers too. For her it seemed shameful. A girl that she was friends with at the orphanage became one....It was...a thing to remember for her mental health that's for sure...Tsk..She wanted to forget a lot of the memories there. However...She knew how to solve this puzzle. It looked like a game you'd see in an Arcade. She used to search for coins on the ground and around the building and sometimes she'd get coins from some of the workers there if they pittied her. She didn't mind as she would always get a bag of sweets for 10 cents and use the rest for the video games. 

She put the hand on the lever and started moving it around in a pattern that was technically supposed to move the blocks so she could shoot the target. She solved it in around 2 minutes and was ready to move on. The left side was the same story, except for a laser blocking the way. Frisk scrunched her nose up and looked around. There were bars holding the lasers up so they could block the ways. She used it to help herself up and jump over the laser. The other two humans on the other side looked at her in disbelief. Sans just shrugged and teleported next to her with his lazy demanour. Alphys called them soon after and got rid of it. Then she met Grillby's daughter! Her name was Fuku and she had her hair a gradient from blue to green. It suited her! The other girl seemed to be her classmate or schoolmate as they had the same uniform and were hanging together.

They finally passed the northen door and as she was about to jump on the pipes her phone started ringing. Sans swiftly caught her with his blue magic and pointed at the bag on her back. She sighed and answeared. 

"Umm..I think uhh...Hey! About the puzzles on the left and right...they're a bit difficult to explain but--" Sans laughed. 

"she's already done 'em alph." Alphys was silent for a second.

"uhhh, you already s-solved them..? O-oh...Awesome! hehe..." And the phone call ended. Sans snorted in his hand and Frisk frowned at him. 

"what...? i had to tell her.." Frisk frowned even more. 

"don't tell me you think that was rude." Frisk gave him a stern look. 

"oh come on! i couldn't just let her explain it if you've already done it." He waved his hand over his face and the skeleton magic was back. 

"throw me a bone here pidge-OWW!" He said as the skeleton magic faded and a small rock hit him in the head. He rubbed the spot. 

"a BONE, not a rock.." Frisk smiled as she grew in size. 

"but if you look closely...it's a fossile~" Sans looked at the rock on the ground and she was right. She was now doing loops in his magic. 

"oh you cheeky little-- oops! it slipped!" He said as he let Frisk fall next to to pipes with her butt up. She growled as her tail wagged in annoyance. 

"pfft--" And he started laughing, and soon enough she joined in. 

"Ok ok ok! be serious Sans! It's a very important mission! We must be serious ok..?"

"ok ok.." He said. She gave him a pat on the shoulder. 

"be serious...down to the bone alright?" He froze and started laughing again as she jumped on the other side. Of course our lazy human companion teleported instead of jumping and the two kept walking. What was weird however...was the fact they walked on a tilted ground. They entered a room that was pitch black. Her phone rang again. Alphys was calling:

"H-hey! It's kind of dark in there, isn't it?" Sans laughed. 

"no shit sherlock. He tried using magic to light the place but it was useless. Frisk poked him in the ribs with her elbow. 

"Sans!" She said frowning. 

"ok ok ok...sheesh...sorry.." He rolled his eyes. 

"i-it's fine. I-I'll hack into the light system and brighten it up!" Frisk sighed and the two waited a few seconds. 

"and god said 'let there be light'..?" Sans said as a joke and Frisk went howling with laughter when the lights came on. 

"hold the fuck up-" Sans said as he looked at his hands confused. But then they looked around and noticed the setting they were in. A cooking show kitchen type of studio.

"Oh no." Alphys said over the phone. The setting was cute. A wall with a fridge, a sink, counters and a stove, also some ingredients and a microwave. In front of the wall, on Frisk's other side, more counters, facing a flying drone that was filming this whole thing. The was was a pastle yellow with a fake window showing a nice green scene with a bright blue sky and clouds. The courtains on that window were also yellow. The floor was a pastle teal with yellow dots. 

"anything but that tin-ca--HOLY MOTHER--" Sans said as he was now tied up in confetti again and fell on his back. 

"Sans! Are you ok?" Sans sighed as she sat up. 

"i'm fine, sweetheart...just a bit tied up i guess...oh no..." Sans said as he looked behind Frisk. She looked as well behind her and gasped as the robot was wayyy too close to comfort. She backed away a bit. Sans snarled. 

"OHHH YESSSSS!! WELCOME, BEAUTIFUES, TO THE UNDERGROUND'S PREMIER COOKING SHOW!!!" Sans struggled a bit more but the confetti only tightened around him as he made his way towards Frisk. 

"PRE-HEAT YOUR OVENS, BECAUSE WE'VE GOT A VERY SPECIAL RECIPE FOR YOU TODAY!" He dramatically pulled Frisk in and let her bend down like in a dance. 

"hands off fucking tin-can.." But Mettaton ignored him as he gave him another party horn. Sans blew into it then spat it out, annoyed. The robot dropped Frisk on the floor as he was looking at the drone with a camera. She groaned. Sans was gritting his teeth in annoyance.

"WE'RE GOING TO BE MAKING....A CAKE!" Both Sans and Frisk were confused on why she didn't seem to have to do anything. Maybe they just walked in at the wrong time?

"MY LOVELY ASSISTANT HERE WILL GATHER THE INGREDIENTS!" Frisk face-palmed. There was always a catch, wasn't it?

"EVERYONE GIVE THEM A BIG HAND!" Fake applauses recorded in a studio started playing. The camera zoomed in on her and more confetti fell on her. She shielded herself from them and frowned. She hated cameras. She wasn't fond of confetti. She picked a few out of her fur and twisted them between her fingers. 

"WE'LL NEED SUGAR, MILK AND EGGS. GO FOR IT..." He paused and looked at Sans. 

"SWEETHEART." Sans struggled some more to get out of his binds. Frisk looked around for the ingredients. She picked them up and set them on the counter in front of Mettaton. She crossed her arms and waited. Her tail was wagging in annoyance. 

"MILK....SUGAR.....EGGS....WE'VE GOT EVERYTHING WE NEED!" He looked at the camera for a second too long then turned to her. 

"OH MY! WAIT A MAGNIFICENT MOMENT!  HOW COULD I FORGET!! WE'RE MISSING THE MOST IMPORTANT INGREDIENT!" Frisk raised an eye-brow. 

"I believe you're missing more than on--" 

"A MONSTER SOUL!" He said as he pulled out a chainsaw. 

"HOLY SHI--" He started inching closer and Frisk backed away. He cut the counter with all the ingredients on it as he tried to hit her. She dodged. 

"FRISK!!" Sans yelled. She was now with her back against the wall. Sans then yelled. 

"WAIT! what if errr...someone...is..umm...vegan..??" Mettaton stopped. 

"VEGAN..?" Both him and Frisk were sweating bullets at that point.

"uhh..yeah...?" Sans said hopeful. 

"THAT..IS.....A WONDERFUL IDEA!! I HAPPEN TO HAVE ONE AT HAND! THE MTT-BRAN ALWAYS-CONVENIENT-MONSTER-SOUL-FLAVOR-SUBSTITUTE!" Frisk sighed in relief as Mettaton let his chainsaw retract and he turned towards the audience. She slid down the wall and took in deep breaths. 

"A CAN OF IT IS OVER ON THAT COUNTER! WELL, DARLING? WHY DON'T YOU GET IT?" She walked over to the counter, reluctantly. She always looked behind her at the suspicious robot and reached for the can. A loud rumbling noise came from the ground which caught Frisk off guard and she backed away. The counter shot up, underneath it being a huge tower of counters. Frisk watched in dread as the counter was getting further and further away. 

"BY THE WAY, DOLL: OUR SHOW RUNS ON A STRICT SCHEDULE! IF YOU CAN'T GET THE CAN IN ONE MINUTE....WE'LL JUST HAVE TO GO BACK TO THE ORIGINAL PLAN! SO BETTER START CLIMBING, BEAUTIFUL." Her phone started ringing. 

"A-are you ok?! Y-you can't possibly climb up!!" Frisk frowned and opened her eyes who shined red. 

"i won't have to climb....." She said. 

"w-what do you mean?? F-Frisk wait--" But she ended the call and summoned her wings as she flew up. The robot flickered red. 

"OH NO YOU DON'T DARLING!!" He took the ingredients and both were now flying up, with Mettaton in front of her. He started throwing them down. Sugar, eggs, milk, all was flying down to stop her but she knew how to fly. She would fly with her brother between the branches in the forest surrounding the edge of Ebbot City. She smirked and started dodging. Mettaton was growing quite irritated. 

"COME ON FRISK! THERE'S 20 SECONDS LEFT!!" Frisk fluttered her wings a few times and she was at the top. The robot came soon after her. 

"MY MY. IT SEEMES YOU'VE BESTED ME! BUT ONLY BECAUSE YOU'VE HAD THE HELP OF THE HUMANS, OF COURSE! OH, I LOATHE TO THINK WHAT WOULD HAVE HAPPENED TO YOU WITHOUT THEM!! WELL...TOODLES!" The robot left, flying in another direction as Frisk slowly came down. When she set her feet to the ground she was picked up and twirled around, then pulled into a hug. Her eyes widened as her face flushed deep red. 

"oh thank god you're ok....that bastard...frisk, that was fucking amazing! you should have seen yourself...it was...beautiful.." Now the human was blushing as well. She started giggling and punched him in the shoulder. Then they heard a cough. 

"-ahem- S-sorry to interrupt your 'moment' but i am still here..." Both Frisk and Sans jumped up and she almost dropped the phone as she picked it from her pocket. 

"y-yeah the call was on for the whole time. i-i have to agree with Sans, y-you did amazing! G-go team! Hehe! A-anyways we need to keep heading forward. Frisk started walking forward and Sans face-palmed. He was stupid to do that...why did he do that...Now the biggest 'shipper' out there was on his ass. Fucking great. What a day to be alive! He grumbled and caught up to Frisk by teleporting next to her. She was looking in the distance. 

"wha'cha looking at sweetheart..?" He froze. 

"oh." He said. Frisk was looking at the Core. His father's greatest invention and what was powering the whole Underground. A building made out of metal in the middle of a lake of lava, giant pipes, wires and just an amalgam of structures in general made that thing. They stood there for a second. Alphys called them. 

"S-see that building in the distance..? That's the Core. The source of all power for the Underground. It converts geothermal energy into magical electricity by.... uhh...anyways that's where we're going to go. In the Core there's an elevator directly to Asgore's castle...And from there you can go home." Frisk frowned at that. Sans noticed it. The call ended but they still stood there. 

"what would you do....if you had to choose between returning to a place where you have no place...and helping human kind be set free by sacrificing yourself...?" Sans flinched at the question and looked at Frisk. She was serious. Her honey yellow eyes were now dull and dark. What was she thinking..?

"sweetheart...you can't possibly be thinking that." Frisk sighed. 

"i can't just leave you all here to rot...i..." Frisk closed her eyes. Sans pulled her into a hug. They stood in silence as the sound of the bubbling lava was the only thing that could be heard. 

"frisk...don't." He said, breaking the silence. 

"starlight...i can't just leave you all down here and go back there...knowing everything i do, living the way i do...it's just pointless. You all deserve happiness. To see the sky, to leave alongside monsters on the Surface!" Sans snorted. 

"you're either gonna chicken out or just messing with me." Frisk frowned as she pulled back. 

"Don't tell me you've never dreamt of going to the Surface...?" Sans chuckled. 

"of course i did. i dreamt of seeing the real stars. that was before all the RESETS. i kinda lost all hope. listen. don't make promises you can't keep." He was about to walk away when she caught his wrist. 

"Sans the human, i promise you, i will do everything in my power...To make your dream come true. You will see the stars, i promise." Sans looked at her and blushed. Then he started laughing a sincere and happy laugh. He hugged her. 

"don't bet your life on something so stupid...ok..? now come on..we're close to that tin-can's resort." The two started walking in silence. But Frisk wasn't paying attention. He said he didn't want her to do something stupid, right? Freeing them wasn't stupid...and even if he thought it was... Frisk didn't back down...

Frisk was determined!