Archive of Our Own ^beta

Chapter Text

Sans and Papyrus. They had to find Sans and Papyrus.

Gaster lead Toriel and Frisk through the cold, barren wilderness of Snowdin Forest, walking a few feet in front of them. He knew what was coming. He knew who they had to see, what they had to do, but he just wasn’t prepared. He didn’t know how he even could prepare. He was a new variable. He didn’t know, he couldn’t know how they'd react. He didn’t even see their initial reactions to his disappearance: he was too focused on the nature of the Void to do such a thing.

Sans… Papyrus… his sons… Oh, it must’ve been so long. He could hardly remember the last time he saw the two outside the timelines. And even then, in those timelines, Chara just killed them over and over and over…

He would finally see them face to face again. He would finally see them alive.

In watching the current events of the Underground, Gaster quickly learned that there was no such thing as a satisfying timeline. Ever since Chara took control, nearly everyone was dead, slaughtered by who they thought to be Frisk. And if they lived, they were constantly plagued with the murders of their loved ones until there was yet another reset.

But this time was different.

“Dr. Gaster,” Toriel spoke, knocking the scientist out of his thoughts. He stopped walking for a moment and turned to her. The woman was holding Frisk’s hand as they walked through the cold. “I know you emphasized the importance of time for your plan,” she started somewhat slowly, “but… you seem very anxious, Dr. Gaster… I don’t blame you either.  You’re seeing your sons for the first time in who knows how long, but I don’t think you’ve given yourself enough time to… ah… emotionally come to terms with the tasks ahead.”

Gaster sighed, letting his head hang slightly before looking back at the woman. “Your concern is appreciated Toriel, but I believe many lifetimes stuck in the Void has emotionally prepared me quite enough,” he said aloud, but inside he knew it wasn’t that simple. He knew it wasn’t true.

Originally, he thought that without a full soul, he wouldn’t be able to completely feel or convey emotions. He thought he wouldn’t be dealing with the constant nagging in the back of his mind telling him that they were going to react negatively, or the fact that he could face the dreaded possibility that Chara had already killed them. But all thanks to Flowey, there he was, anxious with hardly anyone being able to understand his words.

Her face almost twisted into a stern stare. “As a mother who has lost her children, I can assure you that no amount of time would stop me from worrying about them, especially when put in the situation you were.” Seeing Gaster stare back at her for a few silent moments, likely gathering his thoughts, she continued, “You need time to gather yourself, Dr. Gaster. You’re walking so fast due to your nerves, I imagine… Frisk can hardly keep up.” Frisk gave a small, somewhat confused smile as Toriel chuckled slightly.

Gaster sighed once more. “If only there were time,” he said. “With my presence and the disappearance of Flowey and Chara…” Another sigh. “...there are too many variables. We have to be as precise as possible.”

He paused. Perhaps Toriel was actually right. Perhaps all he needed to do was stop for a moment and collect himself… After all, he couldn’t save the universe while in his current state, right? “Maybe I do need... just a small break.”

Toriel smiled, but after only a few seconds her expression faltered once more. And Gaster needn’t ask why.

“Heya, you know town's thatta way, right?”

Gaster almost immediately turned around upon hearing the voice. He saw the smile on the other’s face fade in disbelief as he took a step back. Gaster just analyzed him. It was actually him, oversized coat and all… There was no monster dust, no cyan iris, none of that. It was just him. It was just his son.

“Sans...” Gaster said quietly as his son continued staring at him with an astonished gaze. The memories suddenly came flooding back.

The memory came clear as day, as if it had just happened a few moments ago. He was walking through the swamps of Waterfall (he had to venture to Snowdin to get a few supplies and was then on his way back to New Home). He was in a rush, hoping that he could make it back to his lab with fresh ideas on his mind. But, as fate would have it, what happened didn’t line up with his predictions.

He heard a cry. The cry of a baby, the pleading of a child… “Please… will you…? We… We need help! We were just left here! We don’t have a home! Please… someone help…”

It was a young skeleton child who couldn’t have been older than six or seven with his baby sibling in his arms. Gaster’s face fell at the sight. They were two abandoned children, crying into the darkness for a helping hand, yet no one would even offer it to them. Monsters walked by as the child continued begged for any sort of assistance but continued to get none.

He couldn’t bring himself to walk on like the others. He couldn’t just leave these two out in the dark of Waterfall… Thus, Gaster approached them, the boy’s face brightening slightly as he stopped and knelt down to their level. “What brought you two here?” he asked softly.

“Our parents didn’t want us anymore,” the kid replied hesitantly.

How horrible! Gaster thought. “Well, my name is W.D. Gaster, and it appears since you have no home, you can come with me to live in my own,” he said.

The child perked up at the words. “R-Really?! You’ll let us live with you?!”

“Of course.”

The kid stood up, careful not to drop his baby sibling. He followed Gaster through the rest of Waterfall. Just before they reached Hotland, the boy said, “Oh! My name’s Sans! And this is my brother, Papyrus.” By then, Papyrus was already asleep.

Sans and Papyrus. The boys seemed so sweet… how could anyone just abandon them like that?

Another memory soon overpowered the current one. Both Sans and Papyrus were older, Papyrus finally being old enough to speak. Given that he didn’t necessarily have anyone to watch over the two while he went into work at the King’s Castle in New Home, he decided to take them with him.

“Your bosses are the King and Queen?” Sans asked curiously as they entered the castle. Stone floors and walls surrounded them as they passed by many rooms; some that were off limits, some that he’d been in before, some that he constantly was in and out of.

Gaster chuckled slightly. “That’s why I’m called the Royal Scientist.”

“Will we get ta meet them?!” Papyrus asked excitedly, tugging at Gaster’s lab coat. He was about to answer, but the sound of footsteps coming from another room cut him off.

There they stood at the end of the corridor, King Asgore and Queen Toriel. Toriel smiled upon seeing the two boys that accompanied the Royal Scientist. “Good morning, Dr. Gaster,” Toriel greeted. “I don’t believe we’ve had the pleasure of meeting these two before.”

“Good morning, Queen Toriel, King Asgore. These are my adopted sons that I’ve told you about. This is Sans, and this is Papyrus,” Gaster said, gesturing to the boys when he introduced them. Papyrus waved enthusiastically at them, prompting a small chuckle from Toriel.

“Howdy!” Asgore said, walking up to the boys. “My name is Asgore Dreemurr, and I am the King of the Underground.”

“And I am Toriel, the Queen,” Toriel said moments after. “It’s such a pleasure to finally meet you two.” She smiled at the boys before turning to Gaster once more. “Dr. Gaster, are you sure you want to bring them into your lab? From what I’ve observed your experiments can yet rather… dangerous at times.”

“I can assure you, Queen Toriel, I’m not even performing any experiments at the moment. I’m simply figuring out some calculations and drawing blueprints,” Gaster replied calmly.

“But you have previous experiments and inventions in there, do you not? I’m just concerned for the safety of Sans and Papyrus. You’ve gotten critically injured in your lab before, and you knew what you were doing!”

He paused for a moment to think, looking down at the floor. “I suppose, if you’re truly concerned, then perhaps you could watch over them. If that isn’t too much to ask, of course,” he said.

“Nonsense, Dr. Gaster!” Asgore said somewhat gruffly. “Go to your lab. We will watch over your boys.” Toriel smiled and nodded in agreement.

Gaster smiled back. “Thank you, your Highnesses.” He then knelt down to his sons. “You two behave for the King and Queen while I’m working, alright?”

“Yes, Dad!” Papyrus said while Sans gave a simple nod.

“Well it’s settled then. Thank you again,” he said as he walked off to his lab.

The stone of the castle then seemed to morph into white of the Castle Hospital. It was as if  he had just opened his eyes after a long sleep, a long span of unconsciousness. “Dad!” he heard two monsters exclaim. He tried to sit up and turn to face them, but he felt a sharp ache all throughout his body.

“Dr. Gaster, please, lie down. You’re going to experience sharp pain if you don’t. It appears that something in the CORE malfunctioned and left you with a few permanent, uh, scars of sorts… that we could not fix,” the Royal Healer said. “I’m not sure whether or not you noticed… You have a cracked skull, swollen eye, and holes in the palms of your hands. We’re not sure whether or not your magic will heal these injuries overtime…”

“As long as I can keep my position, I’m sure there will be no problems,” Gaster replied, pain clear in his voice as he struggled to speak.

“Yes, yes, of course. I’m sure these injuries will show no effect on your work,” the Doctor assured. “You will have to stay hospitalized for a small while before you can return home.”

“He’s not going to come home with us?” Gaster heard Sans ask, clearly upset.

“I’m afraid not.”

“Sans, you can take care of Papyrus while I’m here, can’t you?” Gaster asked, trying to hide the fierce ache he felt. He didn’t want to worry his sons anymore.

“Yeah,” he replied with a bored (perhaps disappointed) tone of voice.

And that hurt Gaster more than anything, knowing his sons were upset. From the first time he met them in Waterfall to then in the hospital, every drop of sadness he heard in their voice made him tense. “I will be fine, boys. There is no need to worry.”

“...How?” Sans asked, obviously not yet ready to accept that his father had somehow miraculously returned. Gaster could almost read it on his face. “How are you… here ?”

Little did Gaster know that he was speaking just after a memory, much like what he had just experienced.

He heard the doorbell ring. His father (adoptive father, anyways) W.D. Gaster got up from the couch in the den and walked over to the door. He opened it to reveal a flame elemental standing in the doorway.

“Ah, Grillby! Long time, no see, hm?” he said.

“It’s been at least a few months, hasn’t it?” the monster, Grillby said as he stepped inside, closing the door behind him. The moment the door closed, Papyrus came running up to them; Sans had looked up from his joke book. “Hey! How’re the best little skeletons in the Underground doin’?”

“I lost a tooth!” Papyrus announced, opening his mouth to show Grillby the gap.

Grillby’s flame suddenly retreated slightly for a second, showing slight concern. “Uh, that grows back, right?” he asked slowly.

“A new one takes it’s place,” Gaster replied nonchalantly as Papyrus and Sans both chuckled. “That’s normal for young adolescent skeletons.”

“Well, I didn’t spend nine years in college studying the anatomy of every monster in the Underground,” Grillby replied, his flame returning to normal. “I need to know how to prepare food, not examine my future customers.” He adjusted his glasses. “So, is there any reason you invited me?”

Immediately, Sans saw that Gaster’s face grew grim. “Boys,” he said, “why don’t you go to your rooms?” At that, he saw Grillby’s flame recede again.

Without question (though there was a small pout from Papyrus) the two went to their respective rooms. That didn’t stop Sans from pressing his ear against his door in attempt to hear the conversation between his father and his old college friend.

“Was it really necessary to make the boys leave?” Grillby asked.

“I didn’t want to worry them,” Gaster said. “Grillby, I asked to come because I’m about to start a very… interesting experiment.”

“Don’t tell me—”

“Yes, Grillby, this time the outcome could be fatal.”

“W, you can’t do that! These kids’ parents already abandoned them once; they can’t lose the only other parental figure they’ve got!”

“This experiment will help me better understand the nature of human souls. The more I understand the nature of human souls, the closer I am the figuring out a way to destroy the barrier.” Gaster sighed. “I’m taking this experiment very cautiously. Of course I don’t want to leave them. The boys mean the world to me, but the everyone down here is counting on me to get us to freedom.”

“Freedom means nothing if you’ve lost those you care about.”

“I have to do this, Grillby. I’ve already notified Asgore and Toriel and my lab assistants have agreed to report to the lab for the experiment. Please, if anything drastic happens to me, bring the boys to Snowdin with you. Just… please.”

There was a long silence. Sans heard no voices, no shuffling, nothing. Not until Grillby broke the silence with a drawn-out exhale. “Alright, alright… fine. Just promise me you’ll be as careful as possible?”

“...I promise.”

Days seemed to whizz by in seconds. No return of Gaster. Days turned into weeks, seconds turned into minutes. No sign of the Royal Scientist.

They did, however, see Grillby. Though he wasn’t as enthusiastic as usual, and after what had happened, he never was. “Hey Sans, Papyrus. Pack your things! Uh… your dad says you’re going to stay in Snowdin with me until he… gets back from vacation.”

“Wowie! Where’s he at?” Papyrus asked from his room as he began to gather his things.

“...Hotland,” Grillby answered, though he seemed unsure of himself.

But Sans didn’t believe it. He knew what happened to Gaster; everyone in New Home was talking about it. He couldn’t escape it. Every citizen, visitor, and shop owner was talking about how the Royal Scientist fell into his invention, how his molecules split apart as if he were turning to dust, how he had died. But he just simply went along with Grillby and Papyrus to Snowdin, his brother never knowing any news about Gaster’s disappearance.

Gaster saw Sans staring straight at him, likely analyzing him. “I didn’t disappear,” he said slowly. Sans’ expression changed slightly, becoming softer. Thank goodness, he can understand me, the scientist thought. “ When I fell into my machine, I was suddenly in a new state of being. I was in a dark void that showed the timelines, some of which I believe you remember. I saw many lifetimes, many alternatives to the original. But… I left that void. There is a horrible consequence that will happen if I let another timeline be created… Sans… Sans, my son, does that make sense?”

There were no words, but no words were needed. Gaster saw his son’s smile return, tears forming at the edge of his eye sockets. In one sudden movement that Gaster saw to be almost out of character for Sans, the shorter skeleton wrapped his arms around Gaster.

“You have no idea how much I’ve missed you,” he whispered.

“And you have no idea how happy I am to see you.”

Gaster was beyond happy, beyond joyful… It was actually Sans. It was actually his son… but there was something more than that. Maybe, with his return… he would have hope in leaving this place… have hope for freedom.