Requested by: TheShadowWithAPen
Hope you guys enjoy~!

I don't know why, but I have a thing when it comes to being the Experiment!Reader.

~Yumeko-senpai

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"Here you go, Dr. Gaster." You said, as you handed the beaker to Dr. Gaster. He nods, as a "thank you", then he continues his work. You wrote down some notes on what you were doing. "Mornin' Doc." Sans says, as he walks in the room, with a tower of books in his hands. "Morning, Sans. What's your excuse this time, for being 30 minutes late?" You asked, as he lets out a chuckle.

"Picked out some books for research, from the library." Sans says, as he puts on his lab coat. "Is that all...?" Dr. Gaster asks. "Yeap" Sans says, as he walks to his work station. He ends up tripping, and books fall out his hand. There was no impact though. You used your magic to stop the books from hitting the ground, along with Sans faceplanting unto the floor. You help Sans stand up, and used your magic to put all his books on his desk. "Thanks, Sweetheart." He smirks and kisses your cheek. You blush, and smile a bit. "That's real cute, Sans." You said, as he smirked, and nuzzled his face on your neck.

Did I really forget to mention that you and Sans are dating?

"Sans. Please stop with the chemical romance. (Y/N), do your work." Dr. Gaster says, as you both nod. You look into the papers, while typing on your laptop. Multi-tasking. Sans goes to his work station, and does his work. You occasionally help Dr. Gaster, with the files, and shizz.

As hours passed, you decided to take a break, it was already lunch time. "(Y/N). After you finish break, please bring these to Dr. Alphys' lab room. She needs to see this problem." Dr. Gaster requests, as he hands you the paperwork. You nod, as you placed them in your bag. Dr. Gaster smiles, and goes back to his work. Before you left the lab, you walked to Sans' work station, and gave him a kiss on the cheek. He yelped a little, and then looked at you. "See you later, Sans." You said, as you waved at him, and left the room.

You teleported to Grillby's, yes you can teleport, and went in. You ordered, two cups of coffee, a bottle of ketchup and some fries with ketchup. Grillby nodded, and headed into the kitchen. Then the door's small bell rang,

"OH! GOOD MORNING, (Y/N)!" Papyrus exclaims, as he approaches you. "Morning, cinnamon roll." You joked, as you leaned on the counter. "CINNAMON... ROLL...? WHAT DOES THAT MEAN...?" Papyrus asks. You shook your head, as Papyrus sat on one of the chairs.

"So... What are you doing here, Papyrus?" You asked. "OH! I CAME BY HERE TO SEE YOU! I WAS HOPING YOU COULD HELP ME GET TO DAD'S LAB. PLEASE? I HAVE TO TALK TO HIM, FOR SOMETHING ABSOLUTELY IMPORTANT!" Papyrus exclaims, as you let out a giggle. "Of course, Pap. If it was that important, why didn't you say so in the first place?" You said, in sarcasm. Papyrus sighs, and Grillby comes back with your order.

You payed for them, and teleported back to the lab. You and Papyrus, were about to head back to the lab, but you almost forgot about the papers that you needed to give to Alphys. "Hey Pap. Could you give this to our Dad, and Brother? I have to give something to Dr. Alphys, for a bit." You requested, as you handed him the drinks and food. Papyrus nods, and runs off. You took a sip of your coffee, while you teleported to the entrance of Alphys' lab.

You knocked on the sliding door, only to be instantly opened by Alphys. "O-Oh! H-Hi, Ms. (Y/N)! W-What brings y-you h-here?" Alphys asks, as she lets you in her lab. "Oh, uhm... I'm just here to drop off these papers from, Dr. Gaster." You said, as you used your magic, to hold your coffee, while you get the papers from your bag.

You hand them to Alphys, and she examines them. "Well, I better head back then. I've gotta give these to Dr. Gaster and Sans." You said, as you were about to teleport, until Alphys tugged on the sleeve of your lab coat, gaining your attention. She had this uncomfortable look on her fave, you knew something was wrong.

"Is something the matter, Dr. Alphys?" You asked, as you faced her. "N-No... I need your held, Ms. (Y/N)... It's v-very important! It will o-only take a l-little bit o-of y-your time!" Alphys pleads, as you thought about it. You sigh, and nodded. "Okay, what do I need to do?" You asked, as Alphys' face lit up. She grabbed your wrist, and pulled you to another room.

It was the True Lab. "Uhm... Dr. Alphys...? What are we doing here...?" You asked, a lot confused. "I... Need you to help me... With one of my experiments... They've been acting really strangely lately..." Alphys mumbles the last part. "Alright then, Alphys. What do you need me to do?" You asked, as you and Alphys entered the hallway of Alphys' experiments. You both stopped in front of a large clear door.

"I... Want you... To tell me... What you see... If you can do that, alright?" Alphys says in a shy manner. You tilted your head in confusion, but decided to shrug it off. You looked into the clear glass, seeing something under the light. It was Black, and it was dripping. "Alphys. I want to take a closer look." You said, as Alphys' eyes widened. "W-Wait what?! We don't e-even know i-if it's h-harmless! You c-could g-get hurt, o-once you step i-in there!" Alphys says, as you sighed.

You snapped your fingers, and you were instantly in the cell, with the Black Experiment. "MS. (Y/N)! GET OUT OF THERE!" Alphys yells from the outside. You ignored it and approached the experiment. Alphys tries to open the door, but you sealed it with your magic. "MS. (Y/N)! THAT EXPERIMENT IS CURRENTLY UNSTABLE! YOU COULD DIE!" Alphys yelled, as you turned to face her. "You requested me to help you. I'm not turning down the offer, Dr. Alphys." You said, as you approached the experiment.

It lets out an evil grin, bits of sweat rolled down your head. As you approached it slowly, you started to hear voices in your head. You ignored it, by using your magic. "Oh....? What do we have here....? Are you the one.... that Dr. Alphys, has been... talking about....? You're.... quite persistent...." It says, as you stopped in your tracks. "You're different, from the other experiments. Why is that?" You asked, as you placed your hands in the pockets of your lab coat. It let out a dark chuckle. You swallowed a lump in her throat, as you stared at it.

You readied your magic, just in case it attacks you. "Tell me... (Y/N).... What are your dreams....? I really.... really... want to know...." It said, as you stared at the experiment. "I want to be intelligent. That's it." You said, as it let out a dark chuckle. It tried to take a step forward, but when it did, you aimed your hand at him. "Don't you dare move from that spot." You threatened it, as it went back to his position.

It stayed silent, as you glared at it. "Alphys. Whatever you do. Don't open the door." You said, as Alphys nods her head. You face the experiment again, as it kept on grinning at you.

You knew it was planning to do something, not good. It takes a step forward, only to be attacked by you. It shrieks, as you smile to yourself, but it soon fades when you see the experiment absorbing your magic. You aimed your magic again, and fired at the thing. It absorbed it again. "What the bloody hell...?!" You whispered, to yourself.

~Meanwhile~

"HELLO MY DEAR BROTHER, AND FATHER! IT IS I, THE GREAT PAPYRUS! AND I HAVE BROUGHT YOU LUNCH!" Papyrus exclaims, as he enters the lab. "Hey bro, where's (Y/N)?" Sans asks, raising an imaginative eyebrow. "OH! SHE'S HELPING THE GREAT DR. ALPHYS, WITH SOMETHING." Papyrus answers, as he gives Sans his ketchup and fries, along with Gaster with his coffee and fries.

"Oh... I only said that she should give the papers, I wonder what Alphys has in mind this time..." Dr. Gaster says, as he sips on his coffee. "Whaddya mean, Dad?" sans asks, as he drinks his ketchup. "Dr. Alphys reported to me that one of her experiments, were acting stranger than the usual strange." Dr. Gaster says, as he sips on his coffee. 

"OH! SPEAKING OF DR. ALPHYS! I SHALL VISIT HER! I HAVE SOMETHING FOR HER TO SEE!" Papyrus exclaims. "What would that be, Papyrus?" Dr. Gaster asks, as Papyrus pulls out something from his pockets. "I FOUND THIS IN THE DUMP, I BELIEVE THAT DR. ALPHYS CALLS THIS YA.... YAOI HENTA-" before Papyrus could finish, Sans snatches it, and shoves it in his lab coat.

"Don't worry, Pap. I've got it covered." Sans says, as he was about head out the lab, but got stopped by Papyrus. "I ALSO HAVE A BUNCH OF THEM, FOR DR. ALPHYS! IT'S BETTER IF I, THE GREAT PAPYRUS ACCOMPANY YOU!" Papyrus exclaims, as Sans sighs in defeat. "Go on, my sons. I have my work to do." Dr. Gaster says, as Papyrus and Sans leave the lab, and head to Alphys' lab.

~Back To Alphys' Lab~

"M-Ms. (Y/N)...? S-Should I open the door...?" Alphys asks, as you shake your head. She gulps, and watches from her view. "No." You firmly answered, still keeping eye contact with it. The experiment crawled towards you in a fast way, and tried to attack you, but before it could you used your magic, to shield yourself. It didn't stop there. The black substance kept pushing on the shield, while you tried your best to keep your shield, still intact.

The shield started to form cracks, due to the pressure. Black substance started to seep through the cracks. Some substance started to attach themselves on your clothing, and were currently injuring. You held in the urge to scream out in pain. Your HP was decreasing by the second. Blood poured out each wound it created.

"You aren't.... going to... last long... Doctor... Just give... up...." It persuades, as you began to back away, while you are still trying to keep your shield intact. You scanned the room, to see tazers around the room. You scanned the outside of the room, to see a red lever labeled, Tazers. An idea sprung up your head, while grinning to yourself. 

You forced your shield on the experiment, as it stumbled back on it's legs(?). You used your magic, to pull the lever, and teleported the fuck out of the cell. As the tazers activated, you heard a shriek of pain. It came from, the experiment. It laid on the ground, as you let out a chuckle. "M-Ms. (Y/N)! You're hurt!" Alphys shrieks, as she runs over to you.

You fell to your knees, while holding your arm. "Heh. Guess I was just careless..." You let out a small laugh. "Ms. (Y/N)! Hold on! I'll get you fixed up, I promise!" Dr. Alphys exclaims, as you lay on the floor. "I know you will, until then.... Just let me rest for a little.... while...." your voice trails off, as your eyes colsed. You were resting. "OMG! OMG! OMG! I need to fix her before Sans-!" Alphys panics.

She looks at her doorway to see Sans, with blank eye sockets, and Papyrus with the emotion of fear on his face. Sans runs over to your side, and places his hand under your head, and lifts you up. Your eyes slowly opened, and you smiled at him. "Sweetheart....?" Sans whispers, as tears streamed down his cheek bones. "Sans... I'm going to be alright... It's just a few scratches..." You reassured. "You're bleeding, sweetheart! Don't say that you're alright!" Sans yells. "I just need rest, Sans, and before you know it, I'll be fine. Alright...?" You said, as Sans nods, and holds your hand up his cheek.

"IS (Y/N) GOING TO BE ALRIGHT...?" Papyrus asks in a worried tone. You closed your eyes, and let yourself sleep. Sans hugs your head, while hearing a dark chuckle from the black substance. Sans looks up at it, and shoots his Gaster Blaster at it. It turns to dust.

~3 Days Later~

After that incident, you were stuck in Dr. Gaster's regeneration room. You were asleep for three whole days. You were still alive, but your breathing be came slower each day. Sans would always visit you, and whisper sweet things. 

Once you woke up, Sans was relieved, and yet disappointed. When you saw him, you pushed him away. Sans was confused. You went on a rampage. You needed a cure. You didn't know what happened to you. You don't even know what happened, or what is happening, when you go into a rampage, all that you know is that it was a nightmare. Once you go on a rampage, you become a completely new, yet violent person.

They never gave up on finding a cure for you, especially Sans. He visits you every single day. He's taking a risk. He would always say that he wants to help you, but it always ends up you on a rampage.

"(Y/N)! Please! I want to help you!" Sans yells, as you back away from him. "Stay away from me, Sans! I don't want to hurt you!" You yelled back, as you aimed your magic at him. He swiftly dodges it, and slowly walks towards you, step by step. "Stand back! I don't want to hurt you, Sans!" You yelled, as tears fell down your eyes. "I know you won't hurt me, (Y/N)." Sans says, as you started to back away, from him, still aiming your magic at him. "I swear in the name of Asgore! I'll hurt you! Just stop!" You pleaded, as never-ending tears stream down your face.

You kept backing away, and eventually your back hit the wall. Sans has his face inches from yours. He strokes your tear-stained cheeks, while he stares into your black, and (F/C) eyes. "Please.... Stop...." You said, as tears kept streaming down your cheeks. Sans wipes them away, along with a smile in his face. "We're here to help you. Don't let it consume you, 'kay Sweetheart?" Sans says in a calming voice.

"I'll try my best... for you, Sans..." you said, as you hugged him. Sans hugs back, and kisses your forehead. "We'll give it everything we've got. We will find a cure, until then.." he kisses your forehead again, "Please stay strong... You can do that, right?" Sans requests, as you reply with a nod. "Thank you, Sans... I love you..." You whispered, as Sans strokes your hair.

~Timeskip~

They found a cure. Dr. Gaster just injected it, leading you to vomit bits of black substance on the floor. "I-Is tha-at suppo-osed t-to ha-a-apen?!" Alphys asks, rather terrified. "It's the only way to remove the black substance from her body, and SOUL." Dr. Gaster says, as Sans places his hand on the glass window. 

You stood up, and wiped the remaining black substance on your lips. You looked at them, and you're eyes were normal. Sans opens the door, and runs over to you. He hugs you, and twirls you around. "I miss you so much, Sweetheart." Sans says, as tears streamed down your face. You hugged his head, while he hugs on your waist.

"YOU DID IT, DAD! (Y/N)'S GOING TO BE ALRIGHT!" Papyrus exclaims, as he hugs Dr. Gaster. He smiles, and gives Papyrus a pat on the back. Alphys smiles at this, and approaches you and Sans. "Listen, Ms. (Y/N)... I'm r-really sorry... about... this... I wasn't-" before she could finish, you smiled at her, "It's okay, Al. I'm alright, and so are you. Nothing bad to any of you, that's what matters." you said, as Alphys nods, and lets a few tears fall down.

Sans puts you down, and kisses you on the lips. You kissed back, while wrapping your arms around his neck. He wraps his arms around your waist. You pulled away, and caressed his cheek. "I love you, Sans." You said, as he smiles. "I love you too, Sweetheart." Sans whispers

~End~

I'm sorry, if the ending sucks. I was lazy, and a crappy author when I wrote this. Plus, I was in front of the computer since morning. It's like 4:00 PM here. So see you in the next oneshot.

Next Oneshot: Ink!Sans x Reader
Requested by: Neko_Blooky_Chan (Hahaha XD)

~Yumeko-senpai