Chapter 1: The Lost Prince

Undertale hit me kind of hard. I don't know exactly how to explain it, but on a consistent basis of 3 years now, every fall, my mind returns to the monsters of the underground, frisk, and the story that was told. I knew there was two endings and yet they both were difficult to see. This has been in the works since I completed the game the day I bought it. I hope you enjoy it.

UNDERTALE

The Lost Prince

SANS! SANS, SAAAAAAAAAAAAAAANS!

The door to Papyrus's room opened and a smiling but sleepy Sans walked in, rubbing an eye. Sans was a short skeleton with an abnormally large skull. Not only was it abnormally large, it was shaped oddly too. It was rounded all around and had an ever-present smile on it. With two creases leading away from his nose near his eyes, the skull gave the illusion of laugh lines. He was wearing his traditional blue hoodie, black sweats, and pink slippers.

what's up bro? can't sleep?

I CANNOT. I REQUIRE A BEDTIME STORY. PREFERABLY ONE THAT INVOLVES THE GREAT PAPYRUS.

Papyrus crossed his long skeletal arms, staring at his brother. He was sitting in a red racecar bed, which had a rocking chair beside the table, which was next to the bed. Papyrus was much taller than his brother, his skull being more vertical and geometrical than Sans. He was wearing his long pajamas and a bedtime cap, all that covered his battle armor he wore underneath. Sans sighed and walked in before taking a seat on the rocking chair.

You could just ask to hear the one about th-

I WANT TO HEAR THE ONE ABOUT THE LOST PRINCE!

Sans chuckled softly as his brother cut him off. He rocked a bit and his eyes went blank for a few moments.

well. you know how the tale goes. the royal family, who we commonly signify as the first fallen human, chara; our own prince, asriel; and the king and queen. there was, or is, another member of the family. a member to whom we owe so much to. he was lost for a great time, until he finally found himself, and therein, found us. the human-made-monster, aelairron (ah-lair-ron).

The Tale of the Lost Prince is a tale engraved into the stone entrance to the underground, engraved by those who wished to honor his story. Frisk knew this, they knew that the Prince sacrificed everything for them, to save everyone. He had turned his back on his own kind and embraced the underground as his own. But he was lost after an experiment regarding determination. Frisk sat outside the door of Papyrus's room, sitting hunched up, listening.

Frisk was around the same height as Sans now, wearing the same blue sweater with a purple stripe through the center like Chara's, shorts and black shoes. They snuggled against the wall, their brown hair pressing against it.

Our tale starts off with the fall of the first monster. The story, albeit mostly remembered by Toriel and Asgore specifically, as well as a dwindling number of others, refers to the fall of the Lost prince; his decent into the Underground. He was marked as the second human to have fallen in, shortly after Chara, but he renounced humanity for their deeds. His fall rendered him unconscious for a few days, as well as having given him amnesia. He was found lying in the same flowers Chara had been found in almost a year prior. Toriel was tending to the flowers, when he fell, his clothes torn and tattered. She let out a cry of surprise when he landed a few feet away from her. Asgore burst in, looking around before spotting Toriel kneeling over the body.

Toriel looked like an anthropomorphic Nubian goat, with droopy ears and short horns. Her dark red eyes scanned over the boy, her paws resting on her knees. She wore a long purple robe that had long white sleeves that were dipped into the yellow flowers.

"What happened?! Are you hurt?" he asked, and she shook her head, looking back at him. Asgore was a large, bulky anthropomorphic Nubian goat. He boasted broad shoulders, a golden blonde mane and beard, and two large horns. He wore a golden suit of armor, a purple cape, and had a crown with a single gem in the center on his head. His eyes peered down at the boy, and his gaze softened a bit. He walked over and knelt beside the body and placed a large paw on it. His paw was much larger than the boys back, covering it and having room left for the rest of his paw. He removed his paw almost immediately and looked at it, the fur covered in blood. The two looked at each-other.

"If we get him to Gaster, I'm sure he will get better…" he said quietly, looking at Toriel. She nodded and watched as Asgore stood up and turned and made his way towards the door. He made his way past Asriel and Chara, who were hiding in the shadows of the doorway. The two peeked at Toriel, seeing the body in the flowers. She picked him up carefully, and the two sunk back into the shadows again. As she brushed past them, they followed, making sure to stay a good distance from her. Asriel was a short Nubian goat, wearing a green and yellow striped sweater, and grey jeans, while Chara was a human while fair pink skin with two faint blush marks on their cheeks. They had brilliant ruby red eyes and wore a green sweater with a single lighter green stripe running horizontally through the middle. The three made their way to the HOTLAND, moving along an express passage, used by Gaster and the royal family to get around to each of the districts with ease. As they got to the Hotland, Gaster was already waiting outside his lab. He beckoned them to him and opened the door as they got closer. He even let in Chara and Asriel, with the condition they stayed quiet. They got this condition when he leaned towards them with a finger pressed against his mouth.

Gaster was a tall skinny skeleton, much taller than Papyrus was. He wore a long white lab coat over his pajamas, which were white as well. His skull was more oval than Sans or Papyrus's, and had two large eye holes, and a black line, usually curled in a slight smirk, while his eyes were usually large and alert.

They snuck into the observatory room as Toriel placed the boy on the table.

"What happened?" Gaster asked, putting on gloves and removing the vest, jacket, and shirt he had on and tossing it away. His body was covered in cuts, gashes, and bruises. The ones from the fall, the freshest, bled freely, although lessened since Gaster's left eye turned blue. The boy's body was outlined with the same blue, and the blood began to slow its outward flow. Several disembodied skeleton hands appeared, all with holes in their palms, and they began to stitch and clean up his wounds. These moved with an orange outline, which was the same color as his left eye now, his eyes darting up and down his form. Asgore and Toriel watched from behind, glancing at the monitor ever so often as Gaster worked.

The room had been eerily silent since Gaster had begun working, the two having yet to answer him. Toriel seemed to realize this as she shook her head and swallowed.

"I was tending to the flowers and he fell. Same place Chara was found." She said, and Gaster made a noise, the hands wiping the blood from the boys back and head as he began to bandage the wounds himself. "Interesting. And so soon after…" He muttered, turning him over gently. He sighed and turned to them, taking off the blood-stained gloves and apron.

"Well, he'll be fine. I don't know what you are doing to those flowers, but you've now had two humans, one much older than Chara, fall onto them and not succumb to a coma. Continue to do what you're doing." He said, a smile coming across his face. Toriel bowed her head slightly and smiled.

"I'm glad he'll be alright. We should let him rest here for now, wait for him to wake?"

"I'm sure he'd rather be in a bed waking up than a monster laboratory, would you not agree?" Gaster said, putting his hands in his lap coat pockets. Toriel and Asgore looked at each other and nodded.

"I suppose that'd be better. Perhaps he wouldn't lash out as much." She said, smiling somberly. Asgore picked him up and carried him in his arms with Toriel out of the Laboratory. As they left, Gaster dusted his hands off and peered at the two in the Observatory room.

"Looks like you might have a new brother." He said, chuckling. He walked out of the lab, the two close behind him, staring at the two walking in the distance.

"Another human?" Asriel asked, peering at Chara, who was staring at Asgore's back. Gaster peered down at the two and ruffled their hair, smiling. They looked up at him, smiling back up at him.

"Go on. Head on home, go talk with your folks. I must head home myself. Make sure to stay close to them." He said, walking away, yawning. The two scampered after Toriel and Asgore, once again attempting to stay out of sight. They made their way towards the castle and, after a few staircases and doorways, found themselves in a plain room with a bed, window, and dresser. They tucked the boy into the bed and looked at each other, nodding. They turned to see Chara and Asriel behind them. They smiled softly and beckoned them out of the room, leading them towards the living room, which had a fire place with a nice arm chair, loveseat, and couch in front of it.

"We thought you'd be curious about that boy" Toriel said, Asgore nodding and smiling. They sat on the love seat and sat the two kids on their laps, hugging them.

"We're not entirely sure his story, but we'd like to give him a rest. We can learn what he wants to do after that." Toriel said, looking at the two. "He might be the same case as you, Chara. We will find out, when he wakes, hopefully." She Smiled and the two nodded, smiling up at her. Soon after, Asgore read the two a story and put them to bed in their room beside their guest.

He sat on the loveseat again, having changed in to his own flannel pajamas. Toriel was in the kitchen, making a butterscotch pie humming softly. He was silent for a while, looking at the ground and twiddling his thumbs, before looking up to look at her.

"What will we do if he wishes to leave the underground?" he asked, and Toriel looked at him, pouring the batter into the pie tin.

"Then we guide him to the gateway. We won't keep one here against their will, As." Toriel said, smiling softly at him. He nodded and smiled at her.

"Of course, ... I suppose he might be different than Chara."

"We could only assume." She responded, putting the pie into the oven. She turned around and leaned on the counter, facing Asgore.

"Is it right to assume he isn't though?" he asked, looking up at her. " I mean, to assume without knowing seems awfully rude to the boy…"

"We can only go off what we know, and Chara is the only one to have fallen in since the War. We can see it as a possibility, rather than the norm."

"hrmmm… I suppose that's true… Oh Tori, would it not be grand to have another child?" Asgore said and Toriel smiled at him.

"Of course, it would be. But, let's not get ahead of ourselves. He might not be that way, and we cannot push it on him…" she said, and as she finished she spotted movement outside the window. She looked at it and dropped the spatula she held and gasped. Outside was the boy, who was sliding down a rope, that was once part of scaffolding. He was darting from rooftop to rooftop, making his way towards Snowdin.

As soon as she gasped, Asgore rushed to the window, just to see the boy disappear behind a building.

"He-"

"Ran away?" the two looked at each other and bolted towards the doorway, Asgore grabbing his brilliant red trident as they made their way towards the elevator. He desperately wished he wouldn't have to use it, but if the need came down to it…

The boy had awoken shortly after the two put Chara and Asriel to bed. He made his way out of the window and sat on the ledge, staring at the Underground. He just gazed around, smiling softly. He saw some rope tucked away on a platform outside the window and made use of it, escaping the room. He grinned as he swung past a window, which smelled wonderful. He made his way to it and adjusted the rope, peeking in to see Toriel baking the pie. He licked his lips as he smelled the pie but pushed away from the window and onto the roof of a building, the wind blowing across his bare chest. He winced as he landed, staggering a few times before looking at his chest. It was only scarred in a few spots, on the abdomen. The rest of the scars and stitches he felt on his back, some raw and tender from the fall and the snow. He shook his head and looked around instead around him.

What he saw was a brilliant town covered in snow. This baffled him, and he leaned forward a bit, peering around. The place was lit with colorful lights and decorations. There were several houses that were illuminated on the inside, all covered in snow. The windows had festive plants and colors outside of them, all of which mesmerized him. He fell forward and landed in a pile of snow. He sunk into it and the snow rained down as he laid there. He sat up gently, and looked around, shivering slightly. Although he was freezing and barefoot, he wore a brilliant grin on his face. He peered in each window he passed, looking at the monsters and decorations on the inside.

With every home he saw, the more his smile grew. A childlike expression was painted on his face with every new thing he discovered in Snowdin. From the buildings to the lights; the smells and the colors, the entire place was a spectacle, a shining gem for him to explore all on his own. The monsters were celebrating a winter holiday of sorts, by the looks of it. It looked similar to the Midwinter festival that they had on the surface. Gifts were located under the trees, and there were meals on each table, either being eaten, prepared to be eaten, or already have been eaten.

He crawled from building to building, peering at the homes and their inhabitance. It wasn't long, however, until he heard rushing footsteps and peered over to see the same goat woman from before accompanied by a larger one. He squinted at them and they followed the trail right to him, quite quickly he might add. They stared at him and smiled gently.

"Thank goodness. You are unharmed…" the woman said, and the boys eyes widened a bit. He sunk back behind the building, squinting.

"W-who-whoo are-"

"We are The King and Queen of the Underground; Toriel and Asgore Dreamurr. We took you in when you fell into our home. You just woke up, hours after treatment." Toriel said, looking up at him, smiling softy. Some monsters began to peer out their windows to discover the source of the noise.

"What's your name, young one?" asked Asgore, walking forward. The Boy stared at him and swallowed a bit.

"I…I am… A-aelairron" he said, and the two nodded and bowed slightly before him.

"It is a pleasure to meet you Aelairron. Would you care to join us? It'd be much warmer inside." Toriel asked, gesturing to the blanket she carried. He looked around and sunk behind the building again. Every time he peeked out, he saw them patiently waiting for him. It didn't take long before the cold got to him and he reluctantly moved towards them, his body quite stiff from the cold, making it difficult for him to move. Asgore caught him as he jumped down, his warm paws feeling good on his ice-cold skin. He closed his eyes as they wrapped the blanket around him and picked him up to hold him close.

"Why did you fall into the hole? Into the Underground?" Asgore asked, peering down at the boy, his paw still covering the boy's chest, adding to the warmth.

"I… was banished. That's all I know…"

"You were banished?' Toriel asked, looking down at him, and he nodded. 'how are you certain?" he rose a stiff arm and pointed to his heart.

"It tells me so…"

"So, you were banished to the underground…" Toriel said quietly, the trio making their way slowly to the castle again. "Would…' she started and sighed before continuing with: 'would you like to stay with us then? My husband and our kids?" the boy was silent as she asked, and he looked up at her after some time.

"I… I thought monsters killed humans..."

"oh child… we would not do such a thing. You are safe here." Asgore said, caressing his face gently. Aelairron smiled softly and nuzzled the paw.

"I lost my home up there… I know not why… but…. If I can stay here, I will make myself useful…"

"Nonsense child… you'd be our guest… no… our child." Asgore said and he looked up at them, who were beaming down at him.

"Has anyone told you two that you adopt things quickly?" he asked, tilting his head. The two nodded and he smiled, chuckling softly. 'then… thank you for your hospitality." He chuckled out, bowing his head gently.

"Of course, … But let's get you home to rest. You can look around the underground once we have rested a bit, how's that?" Asgore said, and the Aelairron nodded softly. The Three made their way into the castle and returned him to his room. The two retreated to their quarters and the Underground fell silent once again.

of course, it wouldn't stay silent for very long. although the new human took accustom to the underground must faster than chara, it was clear he had an ambition that far surpassed what toriel and asgore predicted. Sans continued. He rocked back on the rocking chair, with the aid of his power as the chair was not actually a rocking chair. Papyrus stared at him with irritated eyes for doing this but left it alone as it was more work than he had done in ages so, it was a plus. Frisk shifted slightly, to get a better angle for listening, a door creaking at the end of the hallway.

A few years passed, the Underground grew larger and more vibrant than before. New scientists were hired to work with Gaster on what he would call the CORE. As the CORE was built, the royal family happily moved forward as the years went by, and the underground was poised to see a brilliant and bright future... however... there is an old saying within the shadows:

"Death must take place where death has always taken place" Tragedy would strike the denizens of the Underground and would alter their future… forever.