Preface:

This is an UNDERTALE AU I've come upon as I revisited the old UNDERTALE Fandom (especially after the release of DELTARUNE Chapter 1). I am an UNDERTALE enthusiast especially after I discovered the game but this year, I was surfing the net and I came upon the works of TC-96 (ENDERTALE) and Camila Cuevas (GLITCHTALE), I've decided to enter the portals of fan fiction writing once again.

This AU of mine focuses what happens after the monsters escape the Underground. Note, a few character details are inspired by TC-96 and Camila Cueva's AU's—but I promise you a new world as you delve deeper into the story. UNDERTALE and all its amazingness belongs to the great Toby Fox. Without further ado, welcome to UNDERSEQUENCE: an UNDERTALE Story...

Prologue

Forgiveness

Faust never liked the idea of Humans living with Monsters but in a way he doesn't also agree with keeping them imprisoned in the Underground.

Why?

Well to simply put his thoughts together: it's because the creatures that have been living below the surface for hundreds of years have been keeping secrets and advanced technology from humanity—advancements that the Keepers would find beneficial, secrets that the Watchers would like to discover, technology that the Seekers would gladly research on.

Dominic Faust, Master of the Secret Circle of AGEIS will be the one who will give humanity what the Monsters have kept for themselves during their banishment. Faust knows that they were technically imprisoned for an unjust reason and the technology they have was crafted for their survival in the Underground—thus making whatever innovations rightfully theirs alone.

Faust smiled.

Monsters have been inappropriately described as vicious creatures that the Ancient Mages of Corona sealed under the earth after the great 'Human-Monster War', but history says their fate was due to humanity's fear of the Monsters' powers to consume human Souls and become gods. Faust however knows that after a year living with the newly freed creatures, they aren't keen to become soul-consuming gods—in fact, they all seem... friendly. A fact that is established since their return to the surface is that the Monsters have no desire to become powerful gods.

Of course the Young Ambassador of the Monsters clearly emphasized that to the Council during her induction as an official Council-member.

The Young Ambassador... a Human vouching for the Monsters, how interesting.

The girl promised that the Monsters are not enemies to the Human Race. The Council agreed and gave the young Ambassador a chance to prove her words. After three years, the Monsters have indeed proven themselves harmless to Humans.

Except the King...

Faust has seen the Monster King once three years ago. He was a tall creature with the features of a goat. The Council called him to trial after discovering the seven coffins in the Underground's Castle. Faust remembers the mighty horns sprouting from his head that is filled with bright locks of gold hair. The sun shined through the Council's Court making his hair and beard gleam. Looking at the thirteen Council-Members, he spoke a deep but warm and sad voice as he confessed his crime against mankind: the murder of six Human Children.

Outraged, some Council-members cried punishment but the Ambassador of the Monsters stood up to the fallen king's defense. Hundreds of years and the Monsters were desperate to escape the Underground. The Barrier, being sealed by powerful magic can only be shattered by seven Human Souls. The King was in depression for the loss of his son and vowed vengeance against humanity. He promised to free his people and return to the surface. He wanted revenge for being banished for no reason and for the death of his beloved child.

"Young Ambassador, that doesn't erase the fact that this Monster has murdered six innocent children!" Faust recalls Councilman Eric protest during the trial.

The Young Ambassador then pointed out the fact that the Monsters never did anything wrong to be imprisoned in the first place. She reiterates her speech during her induction and goes on to say Humans have been unfair and establishes that both mankind and Monsters are at fault for everything that has transpired.

Some Council-members began to criticize the young Ambassador but the majority was led to reflect on the truth.

Truth...

"The Young Ambassador is correct," Head Councilman Aragorn stated in his seat. All eyes including Faust's darted to him. The old man took a deep breath and stood up. "Our Ancestors have imprisoned an entire race because of fear on something the Monsters are capable of. History says however that the Monsters are gentle creatures and desire no power for themselves..."

"What are you saying, High Councilman?" Councilman Alexander asked as the older man trailed to silence.

Aragorn raised his hands and golden spheres of magic swirled.

"Justice is confused, my friends," He boomed. "Injustices run on both races. Humans for being unequal to the peaceful Monsters because of fear... Monsters for resorting to vengeance due to hatred... Asgore Dreemur, King of the Monsters... arise."

The huge Monster rose from his chair and looked directly at Aragorn.

"For your crimes against humanity... I sentence punishment by banishment..." The High Councilman sighed. "But we have been indeed unfair to your kind... and according to young Frisk's story; the Six Human Souls were responsible for the Underground's Barrier to shatter. And the Young Ambassador said that she was able to speak with them and these Souls were willing to help the Monsters escape."

The crowds began to murmur among themselves but with a strong gust of wind, the Councilwoman Serena spoke with a great voice.

"Frisk speaks of the truth!" She said. Her magic filled the room in the form of strong winds. "I mourned for those poor Souls just as my mother did and hers during their time as the Watcher of Lost Souls. That was until the Barrier was shattered. I felt them, my friends: six children whispered that balance between the two races must be restored."

Faust remembers her golden eyes looking at the Monster King.

"Asgore..." Serena's voice softens. "Your crime is grave... but punishment in the form of banishment has never been a solution."

All Council-members' eyes glowed—except the Young Ambassador.

In unison they all spoke: "The murder of six children scars you, Asgore but so as the failure of losing the war and the guilt of losing your son. You have been in pain for so long... we forgive the atrocity you have done but in return... we ask for one thing."

The glow of the Council-members' eyes faded.

"We ask for your forgiveness as well, King Asgore." Aragorn says in a sad tone.

Faust sneered at the memory. Forgiveness... Asgore and the Council made promises and proceeded to make amends for both of the races' mistakes. It has been three years since that trial and Faust is still reminiscing how the Council came to forgive the Monsters and vice-versa.

Then again, he doesn't really care. Now, his focus is on the recovery of the Monsters' greatest piece of technology: the very thing that drives his motion of spending more time in the empty caverns of the Underground—the CORE.

Three years have passed and he's still in this damned place. Faust stood over watching the giant machines and their Human operators do the work. The CORE has been turned off since the Monsters left for the surface and it has taken a very long time for Faust and AEGIS to bring it back to life.

A very, very long time...

Faust clenched his jaw but sighed to himself. "I am a patient man."

"Indeed," A man wearing a black lab coat approached. The man gave a sly grin at Faust. "But how patient, I wonder?"

Both men stood in the balcony of an observation deck constructed to oversee the process. Lava flowed around the gigantic machine and has been making Faust sweat but he kept his cool as he faced the man in black.

"A long time, Dr. Green," Faust said. "I will wait ten years or so if I have to. I have the patience. Do you?"

Green laughed. "My dear friend, I've been waiting for this opportunity for so many lifetimes. I have a lot of patience to spare... trust me."

"Are you positive that this will work, Dr. Green?" Faust returns his focus on the looming stature of the CORE. "I don't want our efforts to bear fruit as a waste of time."

Behind him, Green smiled sinisterly.

"Have faith Dominic. When the CORE is brought back to life, we'll focus on the other machines. I assure you that this will work... I made the CORE after all."

…

Okay, this is the end of the prologue hooray! *cue the party poppers*

So this is just an introduction on what is happening—sort of. So in this AU Fanfic, let's address Frisk as a "she", I kinda felt like it and using they was kinda confusing haha. So Asgore's crime is absolved and Frisk is part of the Human Society's Council. BTW, the world is fictional and is named "Corona". In this way, I can add places and events easily and it helps the story have a better flow. And of course you've met Mr. Dominic Faust and Dr. Wilhelm Green—the two baddies of the story. Their motives are given a small bit of light here but I know you're confused on what Green meant in the last line. Welp, better tune in hehe.

If I missed some stuff to explain pls. PM me. It would be a great help to shape this AU. Thanks and hope to see ya in the next one. :-P

UNDERTALE belongs to Toby Fox.