Submersion.

Part 1 - Pilot

                  It was a quiet and normal day in the underground, as usual. Monsters went by their usual business, getting jobs done like always.
The king and queen were having a lovely pick-nick in their ever growing flower garden. Their son quickly ran out from their room and jumped onto his father's back.

"Gotcha!"

The king chuckled, quickly turning his head back.

"That you did, Asriel!"

Asriel quickly got off his father's back and jumped towards his mother, who quickly grabbed him and began tickling him.

"NO MOM! STOP!"

The child chuckled and laughed in his words, before his mother chuckled as well, letting go of him and bopping him on the nose.

Suddenly, in that moment, they all heard footsteps getting closer and closer. The king quickly stood up, and was greeted with the presence of the royal scientist, walking in and adjusting his glasses. He was wearing his white robe and held onto a small clipboard.

"Ah, gaster, good to see you today! How goes the work?"

The scientist, whose name was Gaster apparently, quickly looked up from his clipboard, greeting the king with a warm smile.

"Your majesty, how do you do?"

"Oh come now Gaster! We're on a first name basis. No need to call me your majesty!"

Gaster hummed at the king's comment.

"Alright then, Asgore. How are you doing today?"

"Oh quite wonderfully! I was just enjoying a pleasant meal with my wife. You're also on a first name basis with her."

And just as Asgore has finished his sentence, he felt a hand on his shoulder.

"Of course you are, Gaster. You're practically family now!"

The queen said, in her calming and pleasant voice. Asgore quickly chuckled and placed an arm around her waist.

"Indeed you are."

Suddenly, Asriel would pop up from behind Gaster, jumping onto his leg and looking up at him.

"Oh! Why hello there little prince. How do you do?"

"I'm doing great! My magic has been getting stronger by the day!"

"Oh? Why don't you give me a little example?"

Asriel would hurrily jump off Gaster's  leg and put his hand forward, a small fireball appearing in hand before he was quickly cut off by Asgore.

"Woah there! Not here son. We don't want to burn the flowers do we?"

Asriel quickly looked back at his father and sighed, putting both arms down and turning towards him, kicking the ground.

"but i wanna show gaster my magic..."

Asriel mumbled in disappointment. Gaster was quick to react and placed a hand on Asgore's shoulder, whispering into his ear.

"Perhaps the little prince can spend the day with me. It would give you and Toriel some alone time."

Asgore nodded to Gaster's idea. Gaster then walked over to Asriel and crouched down.

"So why don't you come with me and you can show me your magic during some special training? And who knows, perhaps you could even help me with a few 'science' jobs."

Asriel's eyes popped wide open and his ears lifted up.

"You mean it?!"

Gaster chuckled and placed a hand on Asriel's head, ruffling up his fur.

"How does that sound to you?"

Asriel would begin running around Gaster in circles, excited to hear the news before stopping and looking at his father. Before he could say anything, Asgore nodded with a look of approval. Asriel then turned to Gaster, saluting him and stomping his foot on the ground, as if he were a soldier.

"Commander Asriel, at your service!"

Gaster chuckled and began playing along, saluting Asriel as well.

"Well commander, we have some troubles back at the lab. If you could be so kind to come and help me, it would be greatly appreciated."

"It would be my honor, sir!"

Gaster then placed a hand on Asriel's shoulder and looked at Asgore.

"Don't worry Asgore, I'll take good care of him and bring him back in time for dinner."

Asgore would let out an audible chuckle, a hand still around his wife's waist, as he just nodded and waved to Gaster.

"Alrighty then! Have fun you two!"

And just like that, Asriel and Gaster were suddenly gone. They were now in the midst of Snowdin town.

"Alright, firstly I must go pick something up. And afterwards, we can head over to the lab."

Asriel would nod whilst looking around. He had always loved Snowdin, the snow and cold of the wind always gave him a nice feeling. He followed Gaster to a small store, where Gaster picked up a small box that sounded full of metallic parts. Gaster then teleported Asriel and himself to the lab, just like he had promised.

For the rest of the day, they both were just building and working on different projects. Gaster doing actual shall projects and research, and Asriel simply making small mechanisms, and occasionally touching things he wasn't meant to.

Gaster brought Asriel back to his home, where he got a small piece of pie from Toriel, and made his way back home. He had a small house on the outskirts of Snowdin, a nice quiet cabin. He enjoyed walking through the forest, and loved the cold wind blowing on his bones. Though this night felt... Off. As he was about halfway back home, and whilst he was walking through the forest, he heard some footsteps, quickly turning around.

To his surprise, he was met with... A human. A small, human child, in which was just staring at him. He felt uneasy, but cleared his throat and spoke nonetheless.

"Hello there little one. May I ask what brings you to the underground? This isn't a place for humans, after all."

The child slowly began walking towards Gaster, placing a hand on a belt they were wearing and took out a small knife. Gaster suddenly felt uneasy again, and took a step back. He'd never encountered a human before, and didn't exactly know how powerful they were.

"Child, you don't want this. Just put the knife down and we can-"

But before he could finish, the human suddenly dashed towards him, slashing their knife at him and aiming for his head.
But before they hit him, they suddenly found themselves floating just in front of him, unable to move as they struggled. Gaster's one eye was glowing a bright blue shade, a serious expression having spread across his face.

"Fine then, apparently you do."

He then suddenly threw the human backwards, as they began tumbling and sliding on the ground, slowly coming to a halt. They slowly and shakily picked themselves up, staring Gaster down with bloodlust in their eyes. They held the knife in front of them with both their hands. Gaster scoffed.

"You humans truly are as despicable as I've heard. And although you are a child..."

Gaster's other eye suddenly began glowing a bright yellow shade, a crooked smile spreading across his face.

"You'll make it home in a casket."