BBP

by KynTyu

Summary:

Following a small personal revenge on the part of Alphys, Sans begins to rejuvenate more and more until being a baby.

Chapter 1: Prologue

Despite the fatigue, Alphys had continued his project day and night. It must be said that she took it very seriously. She had been brewing this famous potion for a week already. The perfect thing for revenge, she says.
"He'll see… he just not had to laugh at me!" Alphys thought aloud.

-FlashBack-

Alphys was sleeping on the sofa upstairs in the lab. She had been up most of the night because of the finalizations of Mettaton's body modifications. It must also be said that the state in which the laboratory was now was pitiful. With electric wires running around everywhere, boxes of anime DVDs of all kinds, empty packages of instant noodles lying around on the ground, not to mention the many atomic model balls that had been knocked over from their box 2 days earlier, Alphys seemed to be very freakish about cleanliness (-It's not sarcasm ^^).
Sans, had just arrived at the laboratory. Not that shocked at the state of it, given that he could only see the ground floor so far.

" Alphys ? Are you here ? " asked Sans.

One of the scientists who were present got out of the elevator at the end of the room. He looked like a snake with a white coat. It was one of Gaster's former assistants.

" Hey boss ! If you are looking for   Alphyssssss, she is upstairs ! " Said the scientist snake.
" (  sigh ) Isaac, I already told you not to call me that. We are still colleagues and friends, for a while, already. And then, thanks for the info!" Sans replied, looking desperate.

Sans walked up the stairs, with a feeling, as if he knew what he was going to find upstairs. A kind of mixture between fear and the beginning of anger.
When he got to the top of the stairs, he gasped. Anger quickly mounted when he saw Alphys asleep on a couch surrounded by all this mess.

" AAAAAALPHYYYYYYS !!!!!! " Yelled Sans. Which woke up Alphys with a start.

" S-Sans !! Oh... N-no ! Huh... h...h-hello ? Hehehe.. " Alphys stammered timidly.

" HELLO ?! ARE YOU KIDDING ME ?! LOOK AT THE LAB !!! WHEN WERE YOU PLANNING CLEAN THAT UP ?! "

" H-huh... I...I... ' Oh... help ... he's going to kill me... for sure... ' thought Alphys. "

" IT'S ALREADY BEEN THE SECOND TIME, ALPHYS. I WARNED YOU. NOW GET READY ! " Sans still shouted, trying to make his way through the mess. Until he got his foot in a cable and tripped over the balls sprawled on the ground.

It was silence in the room. Alphys stared in awe, Sans who did not move any more, on the ground, the eye sockets completely dark.
A few seconds later, he took a deep breath and calmed down.
Then he laughed.

" Hhh ! Noooooope... Not like this. For you to learn the lesson, no need to go the hard way. Hehehe... " He said getting up, under the questioning eyes of Alphys. Then he left.

The next day, Alphys was at home. Ready to go to Undyne's. She always checked her blog "Undernet" before going anywhere. She then saw that she had received a response to a post the day before. To her surprise, since it had been 2 days since she had posted anything, regarding photos and videos.

「  StrongFish91 : Hum... huh...
Alphys ?

y-yes ? : ALPHYS

StrongFish91 : Can you ... explain to me why you sent me this video yesterday?

The video sent to Undyne showed Alphys training to confess her feelings to her 」

Alphys was shocked and horrified. She had never sent this video to Undyne !! How?! Who ?!
Then she remembered what had happened the day before. Sans. It was Sans who did this. She was starting to have tears in her eyes. She had given up on going to Undyne at first. Out of shame, surely. How did he get this video? Or, who sent him ?!
Heaps of questions swirled around his head.
" SANS !!! YOU ARE..!!! " She stopped. Kid.. It's... It's just a DIRTY kid...
" Hh ! We'll see who the kid is in this story ... You will pay for that ... Gaster Sans. "

.End of FlashBack.

That's it. Alphys had finished the purple-colored potion. She walked over to two scientists, who had stayed here in the lab at that time (- It's around 2 a.m.).
And entrusted it to one of the two. Poggy. A monster resembling a humanoid pangolin. The other was named Nell. He looked like some kind of goblin, though he wasn't.

" You know what's left for you to do. " Alphys told them calmly with a smirk on his face.

The two simply nodded silently and left the lab. Alphys watched them go with a satisfied smirk on his face.

A few hours later, (- They must have slept ^^), the two scientists went to Snowdin.
The two of us headed towards, not the Skeleton Brothers' house, but Grillby's. Being sure to find the skeleton there. And ... they were right.

Chapter 2: Vengeful poison

Without wasting time, the two scientists entered the bar. They were so discreet that no one noticed their presence. As one walked towards Sans, the other went to the counter, a little further from the skeleton so as not to arouse suspicion. Nell had been tasked with creating a diversion while Poggy would take care of pouring the contents of the potion into the ketchup Sans was drinking, as fast as possible so that he would not realize it. The perfect plan. However, there were a few things to keep in mind so that their plan didn't fall apart. Witnesses. And especially the witnesses.
No one was watching. Neither customer seemed to mind the unusual two. And Poggy ordered Grillby to walk away from the counter. It would take him about 5 or 6 minutes ... they had to be quick. Or it would all be ruined.
"Double fries please." Poggy asked politely to the bartender who, in silence, nodded and walked off to the back of the building, presumably into the kitchen.
Nell quickly began to strike up a conversation with Sans, trying to distract him as much as possible.

He began to pat him on the shoulder so that he looked away from the bottle to look at his interlocutor.
“Yes?” Sans asked the scientist whom he had never seen before.
What to say ? We had to invent something. To try everything for everything.

"Uh ... Hey! Hi! It's been a while!" Nell said with stress. Was this going to work?
Meanwhile, Poggy was already starting to pour the liquid into the ketchup.
Sans, of course, noticed nothing, and Grillby being gone, he would see nothing.

"Uh ... do we know each other? No matter how hard I look, your face is not coming back to me ... sorry."
Sans replied to the stranger to him.

Nell was sweating more and more stress. Make it end quickly.
The scientist's wish came true quickly when Poggy motioned to his colleague that he was done and that they could leave.

"Oh, uh ... excuse me! I ... took you for someone else ... y-yes that's it! Heheh ... sorry my friend!"
With those last words, Nell hurried out of the bar, followed closely by Poggy, who was also running.
At the same time, Grillby arrived with the order.

“Sans. Did you see the monster who ordered me that package of fries?” Grillby ended up asking when he finished looking around to see if the scientist was there.

"Sorry Grillbz ... But he just left." The skeleton said frankly, half drunk, and still drinking ketchup. THIS ketchup.
As Grillby expressed his displeasure, Sans began to drink from his bottle. The potion had been created in order to be, in addition to being effective, odorless and tasteless, thus making this little revenge a total success.

At the moment, no particular changes, apart from the fact that Sans was drunk from the ketchup, but hey ... that was normal.
It was the kind of state Grillby hated the most about Sans. Finally ... depending on the day. There were different variations. Be it :
-spent the rest of the time at the bar telling increasingly silly and less funny jokes,
- Behaved really like the worst garbage (this case being really rare, and still happy)
-Start crying and talking about the different timelines and resets,
-Just fell asleep,
Either, and this was the most common, to behave like a real kid.
At times like this, you could almost find it hard to believe that Sans was Papyrus' big brother. Especially since he hated very much that people laughed at his small size and compared him to his brother just about that.

 Especially since he hated very much that we laughed at his small size and compared him to his brother just about that
Time goes by and more and more customers are leaving over time. The royal guards are gone. And only Sans remains at the bar. The remaining customers are, not counting the skeleton, 3 in number, seated at tables on the corner of the room. Some people notice it. And Grillby too. Sans's condition is getting worse and worse. To begin with, his words, which had until then been quite clear, have become sort of incomprehensible sounds. He found it hard to stand when he tried to stand up. And he seemed to be complaining of headaches, which made this one, moreover, blue as a blueberry. He didn't seem to want to joke at all anymore. His soul was burning him. And so his whole body. All this accompanied by excruciating pain. In the meantime, Sans fell from his seat and is currently still lying on the ground. No longer able to make the slightest movement.
Too much ketchup consumption could have the same effects as alcohol, for Sans. But this time the situation looked worse than usual. Was it because of the modified ketchup?
Grillby, worried, picked up the phone, and dialed a number. From a distance, you could enter a voice that bordered on screaming.

"Hello? It's Grillby. Would you mind coming now? ..." Grillby asked calmly.

"OF COURSE! I WILL ARRIVE NOW!" The voice answered immediately that could only belong to Papyrus.

It didn't take long for Papyrus to arrive in front of the bar and go through the front door in an impossible noise. He seemed in a hurry and stressed at the same time. Especially when he saw his brother lying on the ground, breathing heavily and quickly. At the sight of Papyrus, Sans smiled and passed out.

Chapter 3: Strange

Summary:

The next day, Sans acts strangely. But Papyrus tries not to pay too much attention to it.

Notes:

Re hey! Uh ... I don't have much to say actually ... heheh! XD
Just to say that since I'm on vacation tomorrow, I won't have time to write!
Especially since at the moment I have quite a few ideas for another fanfic, which I will start writing tomorrow.
Good reading ! :3

It has now been 6 hours since Papyrus brought his brother home. And Sans still hasn't woken up. For Papyrus, Sans had just been in an extreme state of drunkenness, as he had been before. He didn't care about it. The large skeleton was in the kitchen. He had just finished making the "breakfast spaghetti" as he used to call them. He waited for Sans to wake up and get down on his own to have breakfast, before returning to his sentry post. Even though deep down he knew it would never happen.
He remained seated at the table, his head on his gloved hands, glancing every now and then at the wall clock, which read 7:16 a.m. He sighed and finally stood up, heading for the stairs. He went upstairs, came to his brother's room, and slammed the door violently against the wall of the room.

“SANS !!!” Papyrus shouted as he walked over to Sans's bed.
He stood in front of it for a few seconds, arms crossed, staring at the sleeping form under the blanket. Papyrus leaned forward and grabbed the blanket.

“IF YOU DON'T WAKE UP, I WILL BE FORCED TO DO IT MYSELF LAZYBONES !!!” he said as he pulled and tossed the lime green blanket.
"SAN .....! UGH ?!"
Papyrus stopped when he saw his brother. Snuggles ... and ... sucking his thumb?
"UH ... SANS? WHAT'S HAPPENING TO YOU?"
Sans slowly opened his eyes, removed his thumb from his mouth, and looked at his brother. Not seeming to realize what he was doing a few seconds ago.

“Oh! Uh… Hi Paps! Something wrong?” Sans asked in a somewhat sleepy tone.

Papyrus began to blush. Couldn't he tell him ?!
"UH ... NO NOTHING! II WAITING FOR YOU DOWN FOR ... THE ... BREAKFAST!" He exclaimed with a few stutters.

"Oh ... thank you bro ...!" Sans replied calmly with a little confusion.
Without saying a word, Papyrus walked to the door. He paused for a moment, turned his eyes to Sans, and left the room. His brother was still sitting on his bed with his back leaning against the wall, wondering what was wrong with Papyrus' attitude this morning. He got up and walked to the kitchen as well.
Papyrus is currently alone in the kitchen, standing with his back to the living room. He couldn't help but think back to what had happened.
《STRANGE ... HE NEVER DONE THIS BEFORE ...》 thought Papyrus.
He was suddenly surprised by his brother's voice behind him.

“Hey! What are you thinking bro?” He asked Papyrus as he sat down at the table in front of his plate of Spaghetti.
Papyrus, although surprised, did not turn around. And answered him nervously
"UH ... NOTHING! NOTHING ...".

Following this response, Sans just nodded and looked at what was in front of him.
A very ... special breakfast.
A plate of spaghetti, and ... a bottle of ketchup?

"Uh ... Paps?"
“YES?” Papyrus asked.
"Why this bottle of ketchup?"

Following this question, Papyrus was very surprised and turned around, he who until then had his back to his brother.

"SANS? ARE YOU SICK? DON'T YOU TAKE KETCHUP EVERY MORNING?" Papyrus asked in confusion.
"Well ... I don't see what I could use with spaghetti" Sans replied with a big smile.

Papyrus was more and more confused.
"EH WELL ... IT'S TRUE BUT ... NORMALLY YOU DRINK IT..."

An expression of disgust then took shape on Sans's face.
"Ewww! It's disgusting, Papyrus! How could I drink ketchup like that, with nothing?"

Papyrus just stared at him oddly for a few seconds before breaking the silence.
“IS THAT WHAT I TELL YOU EVERY TIME YOU DRINK ... ARE YOU SURE THAT'S ALRIGHT?” Papyrus asked.
Sans looked at him with a face that meant 'I don't understand'.
"YOU HAVE BEEN BEHAVIOR SINCE THIS MORNING ... DOES THIS RELATE TO THE CONDITION IN WHICH I FOUND YOU YESTERDAY AT GRILLBY'S?" Papyrus said with concern.

"Papyrus ... I'm fine ..." Sans said. Then a smile that looked forced spread across his face. "So don't worry."
Papyrus seemed to have noticed that his brother's smile was wrong. But he pretended not to have noticed anything.
"YEEEAH ..."

With these words, Papyrus began to leave the kitchen to go to the entrance to the living room.
“Where are you going?” Sans asked, confused.

"AT UNDYNE'S ..." Papyrus replied briefly.

The skeleton was about to open the door when he stopped. To Sans's surprise, who was watching him from the kitchen.
Then Papyrus sighed.

"IT'S GOING TO BE THE HUNDRED TIME AS I TELL YOU ... BUT ..." Papyrus began.
Sans was waiting for a response when Papyrus began to scream.
"PICK UP YOUR SOCK AND TOW THIS BEDROOM !!!"
Sans was speechless. When a loud slamming of the door was heard throughout the house. Papyrus was gone.

Notes:

Here ! That will be all for this chapter. Once again, I will try to release a chapter as regularly as possible. :)

Chapter 4: Revenge begins

Summary:

After training, Papyrus shares his concerns with Undyne about his brother's unusual behavior ...

Papyrus was still walking in Waterfall, when he finally reached Undyne's house. He stopped in front of the door and knocked. Without further ado, Undyne opened the door.

“Oh it's you! Hello Papyrus! Ready for your training?” Undyne exclaimed.

He just nodded, smiling. He was trying to hide his concern.
The two started to walk towards the back of the house. Then Undyne moved into a fighting stance.

“Ready ?!” Undyne asked.

Papyrus stood still for a moment, then summoned two bones into his hands, and made a sign that indicated he was ready. Even if it didn't seem. The warrior began to summon a burst of spear, and one she was holding in her hands. Then she started to run towards him. Papyrus was trying to counter his attacks by trying to stay focused on the fight. But in vain. Undyne hit him with his spear, causing him to lose 4 HP. She wins the fight. She could see something was wrong. Usually the fight could last about 10 minutes. Even more, if Papyrus was really motivated. Today it didn't even last a minute. And Papyrus seemed distracted. She leaned over him, who had fallen to the ground after Undyne's attack. She held out a hand for him, which he took and stood up.
“Are you… sure you're okay?” Undyne asked. Papyrus didn't answer. "We can leave it there for today if you want. Come on."

The two made their way inside the house, and Undyne motioned for Papyrus to sit down in a chair.
“Do you want some golden flower tea?” Undyne offered to Papyrus who just nodded in agreement.
After the tea was brewed, she sat down in front of Papyrus, handing him a cup which he took in his hands and placed it in front of him. He wasn't drinking. And Undyne did the same.

"Something is bothering you, Papyrus. Don't think for a second that I haven't noticed it," Undyne began as Papyrus looked at her guiltily.
“I'll put my hand to cut that it was about Sans. Am I wrong?” Undyne announced. Papyrus looked down without saying anything.
"Bingo. So tell me what happened ...". After a deep sigh from Papyrus, he began to tell him all the events that have happened since he woke up.

"IT DOESN'T LOOK LIKE HIM… HE-HE'S WEIRD SINCE THIS MORNING…" he said with a worried tone.

“Well… he's always been weird,” Undyne said as Papyrus began to look at her with an air of 'are you serious there? '
"Papyrus ... maybe he was just kidding you ..!" She continued evidently.
Papyrus began to frown his nonexistent brow.

"TALKING ABOUT Joking ..." Papyrus began.
“Hmm?” She said with a questioning look.
"HE DIDN'T MAKE A SINGLE PUN THIS MORNING ..."
"Oh ... indeed, that's strange," Undyne said slightly confused.
It was silence for a few seconds until Undyne broke it.
"Don't worry! I'm sure everything will be back to normal later. For now, try not to worry too much. Okay?" Undyne said with a smile.
"(sigh) OK ..." Papyrus sighed not too convinced.
Undyne stood up.
"Come on! Go join him! I'll leave your day to you!" She said when Papyrus started to get up from his chair.
"OH ... UH ... THANKS UNDYNE ..." Papyrus replied simply as he started to walk towards the door greeting Undyne to say goodbye to her.

-A bit later-

The door to the two brothers' house opened.
“I AM HOME!” Papyrus announced.
It was total silence in the house. Not a single answer. No one seemed to be there.
"HE LEFT? STRANGE ... KNOWING HIM, SEEN AS HE IS LAYERING, HE WOULD HAVE TAKEN MY ABSENCE TO STAY HERE SLEEPING INSTEAD OF GOING TO HIS POST." Papyrus muttered as he walked into the house. closing the door behind him. He started heading for the stairs when his gaze landed on where the television was.
"HMM ...?" He thinks ...
He looked to the side of the television. The wall half covered with post-it notes. Then his gaze gradually descended to the ground.
"THE ... THE SOCK !!! IT'S NOT HERE ANYMORE" Papyrus exclaimed as he climbed the stairs with insane speed. He quickly pushed open the door to his brother's bedroom.
"SAN ... SSSS .." He stopped in front of what he was seeing.
The socks were put in the washing machine.
The garbage tornadoes were no longer there. Sans's bed (even though it was still only a mattress) was lined neatly with the lime green blanket. Bedroom. Had been cleaned and put away.

Sans, he was lying on his "belly" (?) And was reading a book on astronomy.
He looked away from his book to look at Papyrus who stood at the entrance to his room, speechless.
"Oh! Hi Paps! You're home earlier than expected." Sans said with a smile.
"SANS ... I DON'T BELIEVE IT ..." Papyrus began to say almost in a whisper. Before Sans could say anything, Papyrus rushed over to him, picked him up and hugged him with all his might.

"YOU DID IT SANS! YOU DID WHAT YOU NEVER DONE !!!" cried Papyrus.

"Paps?"

"FINALLY THE ONE HUNDRED TIME WAS THE GOOD BROTHER ..."

“Hey, calm down. It's okay for me to do this. It was dirty and…” “You asked me…” finished Sans in a whisper.

Papyrus looked at him.
“HUH… I GUESS… EVEN IF THAT'S THE CASE SINCE THE BEGINNING, AND YOU NEVER DO," Papyrus said with a suspicious look.

“Heh heh heh!” Sans laughed as his brother put him back on the floor.

“I, THE GREAT PAPYRUS, AM VERY PROUD OF YOU! EVEN IF… I FIND YOUR ATTITUDE VERY STRANGE! NIEH HEH HEH!” Exclaimed the tall skeleton.

"Glad to have made you happy!"