NOTE: This fanfic contains spoilers for Undertale. Proceed with caution if you haven't played the game yet.

This is my take on a prequel of sorts for the game. Yes, an entire 'verse of characters to play with and I pick the ones that only get a brief mention in the game. And yes, I'm aware Charlimane is usually spelled "Charlemagne," but I didn't want people thinking this was the actual historical character.

The humans in this prequel are all deliberate references to humans in the game proper. I won't point out which is which - the reader can have fun figuring it out themselves.

Gaster's depiction in this story is modeled after his depiction in Zarla's "Handplates" comics on DeviantArt.

The chains were hardly necessary. The monsters had surrendered, turning over their weapons and submitting to the will of their captors, not even raising a hand or paw or talon in defense as the human soldiers rounded them up. And many of them were too weak to fight back, wounded or just plain exhausted from combat. But humanity's innate distrust of their kind won out, and the dozen or so captives being herded into the throne room moved only with difficulty, weighed down by iron links and shackles that clattered with every step.

King Charlimane regarded the motley collection of beasts with a calculating eye as he reclined on his ivory-and-bronze throne. As always, he could barely hide his contempt of these creatures – twisted and unnatural, some resembling animals that walked upright as if hoping to ape human behavior, others a horrific collection of mismatched parts, still others so bizarre they defied description. If it wasn't for the fact that monsters could work magic with effortless ease, without burning their life energy as humans were forced to do, he could almost laugh at how ridiculous these creatures looked.

But he held back his laughter. Monsters were dangerous, he reminded himself, the deadliest threat to humankind since the great plagues of last century. However comical they looked, there was truly only one sure way to deal with them – to strike them down and reduce them to dust.

As Charlimane watched, a soldier pushed the tallest of the monsters forward and planted a boot into the small of his back, knocking him to his knees. The white-furred creature kept his head proudly erect even as he crashed to the marble-tiled floor, his scarlet eyes never leaving the human king's. His mane of golden hair was badly matted and snarled, his royal robes torn and stained, his armor dented and even missing plates, and one of the great curving horns had been shattered, leaving a ragged stump a hand's width long in its place. But he continued to regard the human ruler with a calm pride, as if they were equals.

Charlimane's lips curled in a triumphant smile. "King Asgore… at least we meet. I have heard much of your prowess on the battlefield."

Asgore opened his mouth to reply… but another voice, sweet as a running brook but burning with rage, cut in.

"That is all you could have done – heard of it." The second monster, tall and white-furred like Asgore but with much shorter horns and streamlined armor, bared sharp fangs at him. "For you have not the courage to join your troops in battle like a TRUE king. At least my husband fights alongside his people."

Charlimane chuckled. "Queen Toriel… your reputation as the stronger of the monster leaders precedes you. I wish I could say that your reputation extended as far as to give you great beauty."

Toriel raised her muzzle high, glaring, not bothering to reply to the insult.

"Forgive her, Your Highness," Asgore murmured, his own voice a deep rumble. "These have been trying times for our kind. Which is why I came before you."

"Ah yes… I received your message. Your offer of unconditional surrender."

Asgore nodded. "We have no desire to prolong this war. All we want is to live the rest of our lives in peace. We will retreat to the most remote lands possible and never trouble humankind again, if you will but cease the eradication of our kind."

Charlimane regarded the ram-like monster king for a long moment. Then he rose, his green-and-gold robes billowing out like the wings of a dragon as he stepped forward. The human monarch cut an impressive figure – tall and broad-shouldered, golden epaulets exaggerating the width of his shoulders and his long brown hair accented by the bronze crown set with emeralds and topaz that encircled his brow. A golden pendant, crafted in the shape of a heart, hung over his breast from a fine bronze chain, and at his hip hung the weapon that had won him his throne, the legendary True Sword.

He was quite aware that in his most splendid finery Asgore could still outshine him… which was why he had ordered his soldiers to strip Asgore of his trident and crown and ensure his own clothing was ripped and soiled before bringing him in. It would do no good to be outdone by a captive on today of all days, when humankind would finally declare their ultimate victory over monster-kind.

"You speak of mercy," Charlimane replied, clasping his hands behind his back as he paced before the chained monsters. "Of allowing your kind to go free and unmolested. You know very well that I cannot do that, Your Highness. Not when your kind still poses such a threat to ours."

"Threat?" squawked a monster soldier from behind Asgore – a turtle with a ridiculous jet-black beard and with a bloodied patch over one eye. "You humans can butcher our kind in one blow with the right intent, an' WE'RE the threat? Pull the other one!"

"Gerson, enough," Toriel ordered.

"You are weak physically, yes," Charlimane went on, "but when it comes to magic, that is a different matter altogether. Spells drain a human's strength with alarming speed, to the point where even the greatest of our magicians can kill himself by casting too many or too great of spells at once. But you are not only much stronger in magic, but you have the power to take that which is most precious and dear to us."

Asgore frowned. "No monster under my rule would ever take a human SOUL without their consent. We are powerful in magic, yes, but not corrupt."

A page brought a sheet of parchment forward, and Charlimane took it and held it before Asgore. "Then explain this – reports, signed by trusted witnesses, that monsters have taken human SOULs in villages and cities throughout the kingdoms. And not simply SOULs of the dying – live and healthy humans, even children, have had their SOULs ripped from their bodies!"

Asgore refused to back down. "Every one of those cases had extenuating circumstances. The dying wished for a monster to keep their SOUL alive long enough for them to say goodbye to a loved one. And the living had their own reasons, however strange. A young woman with a monster lover wanted their SOULs united in the closest way possible. A man who had lost everything he loved to an enemy granted his SOUL to a monster in exchange for vengeance upon those who ruined his life. And the children you speak of were sick with an incurable plague. The monsters who took their SOULs were granting them the mercy of a peaceful death, saving them weeks of agony."

If Asgore could be stubborn, however, so could Charlimane. "If you can take our SOULs for good causes, you can also take them for evil. And even without the power to steal our SOULs, you are dangerous to humankind. There is no room in this world for both our races, and had you not parleyed for a peaceful surrender I would have ordered your kind wiped out to save humanity."

A blue-and-white birdlike creature, ornate feathers flared out like the spokes of a snowflake, screeched and cowered at those words. A bipedal dog whimpered, while the turtle called Gerson cursed softly under his breath. Even Asgore himself flinched. Only Toriel and a skeleton in black robes and with a crack running through his skull seemed unfazed at the threat.

"Fortunately, for your sakes, I am not so merciless as to ignore a petition for surrender," Charlimene continued. "You came under the white flag of truce, and I shall not violate that. Therefore… henceforth and forever, I decree that monster-kind shall be banished to the caverns beneath Mount Ebott… forever."

Asgore's jaw dropped. "You would not dare… you could not be so cruel…"

"Cruel, Asgore? Cruelty would be to slaughter your kind down to the last mewling cub. No… this is my mercy. To give you a kingdom to call your own underground, where your kind and ours shall never cross paths again. Humans shall be safe from monsters… and monsters safe from humans."

Toriel snarled. "Your mercy is hardly that. You would cut us off from the sun, from the green land, from the villages and fields we have come to call our own! Perhaps to steal them away from us?"

Charlimane said nothing, though Toriel had spoken the truth – he had long coveted the lush valley that Asgore had claimed for the monsters' capitol city, and banishing him and his kind underground would give him the opportunity to claim it for himself. He merely gestured to the figures gathered to one side of his throne, urging them forward.

"My decree has already gone forth," he told Asgore. "And all kingdoms are in accord. Indeed, six kingdoms have sent their own magicians to ensure that the Underground will remain separate from the human lands for all time."

Asgore gaped in shock as the seven beings – Charlimane's own court sorcerer and the magicians from the other lands – arrayed themselves before the horned king. Clad in a rainbow of colors that, in all cases save one, matched the royal colors of the monarch who dispatched them, they all seemed to shimmer with unspeakable power as they regarded the captive monsters.

"Perhaps, my comrades, you would care to explain to Asgore what you have planned?" Charlimane asked.

Grizelda, a short and stocky sorceress in bright cyan robes with her hair elaborately braided in ribbons and a brace of throwing knives in her belt, nodded toward the king and spoke. "We shall combine our strength to form a barrier that will seal the Underground off from the surface world. No monster shall be able to pierce it."

"Impossible," the skeleton insisted, sounding far more indignant about the spell they proposed than concerned about his fate. "A spell of that magnitude takes far more energy than even most monsters can manage. It would kill any human sorcerer."

Bryon, a muscular bare-chested wizard wearing an orange scarf about his head and a pair of steel-studded leather gauntlets, smirked at that. "Not if the seven of us pool our powers together."

"Again, impossible." The skeleton drew himself up as straight as the chains would allow. "Even all your powers combined could not form a barrier that strong. You would destroy yourselves trying."

"It is true that we must make a few shortcuts in order to form the barrier," said Percival, a violet-robed mage with a leather-bound book tucked under one arm and a pair of cloudy spectacles perched on the end of his sharp nose. "'Tis a one-way barrier, for example. Any can enter it… but none can leave."

"Save those with a powerful SOUL," added Honoria. The dancing-witch, so named because her spells were cast through complex dances rather than words, gave a sly little smile, a deceptively tiny and slender sylph in her gauzy dance dress and soft slippers.

"Gaster is right, however," Toriel noted. "Even with this shortcut you speak of, this spell will kill the seven of you."

Gareth, a stocky dark-skinned wizard who wore a leather butcher's apron over his green robes and carried a flattened iron mace on his belt, nodded solemnly. "Yes… and it is a sacrifice we make willingly. Seven SOULs that will keep monster-kind sealed away forever."

"The ritual to form the barrier begins at moonrise," declared Justine, a witch garbed in the yellow tunic and breeches of the Horse People, complete with a wide-brimmed riding hat and a flintlock pistol jammed through her belt. "Tonight shall be the last night your kind walk among us. Good riddance, I say."

Charlimane gave a benevolent smile to the mages, witches, and sorcerers gathered under his command. "Your sacrifices shall be remembered for all time, magicians. I shall ensure that." He lifted his chin and raised his voice. "Guards, take these creatures away! Herd them into the caverns with the rest of their kind and ensure they STAY there until the ritual is completed!"

"You cannot do this!" Asgore bellowed, and tugged at the chains binding his wrists. "We ask you for mercy and you offer us despair in return! You call our kind monsters, but who is the monster now?"

Charlimane drew the True Sword and slashed through the air, bringing the point to rest on the monster king's throat. Asgore's crimson eyes flared wide, and he held still as stone as the human king hissed his reply.

"If I am a monster, Your Highness, it is only because your kind has driven me to be so." He pressed the tip of his blade harder against the white-furred neck. "Go quietly with your people, or I will have my guards muzzle you like a dog before they throw you into the pit that is your new home." He lowered the blade. "Begone."

Asgore lowered his head in defeat as soldiers pulled him to his feet and hauled him away. Other monsters shrieked or growled in protest, only to be silenced with heavy blows. Only Toriel kept her dignity, raising her chin and carrying herself with a regal grace even as she was led away in chains.

"Permission to be dismissed, Your Highness," Percival requested. "We have much preparation before us if the ritual is to be a success."

Charlimane waved a hand. "Permission granted. Alert me when the ritual is about to begin. I want to see this with my own eyes."

"Yes, Your Highness," Honoria replied, bowing deeply before sliding off on graceful feet. One by one the other magicians departed, until only one remained… one who hadn't spoken a word since the representatives of monster-kind had been dragged before the throne.

"Will you not be joining your comrades in their preparations, Friskin?"

The court sorcerer didn't give any indication that they had heard. Unlike their comrades, they did not wear the colors of the kingdom they served – instead of Charlimane's green and gold, they wore a ragged robe of blue striped in a faded magenta, and worn bandages swathed them from head to foot until it was impossible to tell if they were a man or a woman beneath them. They clutched a wooden staff in their hands, unornamented save a polished red stone in the shape of a heart embedded in its head.

"Let me guess," the monarch said with a hash laugh. "You're here to lecture me on compassion and mercy. I do not know what has driven you to appoint yourself as my conscience, Friskin, but all your preaching does is tire me."

Friskin shrugged, and spoke in a soft rustle of a voice. "I advised you to avoid war with the monsters, and you didn't listen. I advised you to avoid this foolishness with the barrier, and you didn't listen. I only have a few precious hours left in this world – why waste them in pointless debate?"

Charlimane narrowed his eyes. "I warn you, Friskin – if you try to sabotage the barrier in any way, I will ensure your final hours are exquisitely painful."

Friskin chuckled. "You needn't worry, my Lord. I have no need to tamper with the barrier's forging. There is already a weakness."

The human king gripped the hilt of the True Sword. "A weakness…"

"Seven SOULs it takes to forge the barrier," Friskin noted, tracing the grain of their staff with a gloved fingertip. "Seven SOULs it shall take to break it. If the monsters can summon a power equal to seven human SOULs, they shall win their freedom."

Charlimane barked a laugh. "Then they shall remain trapped forever! As powerful as their magic is, their SOULs are weak. Why, it would take the SOUL of every monster to match the strength of a human SOUL!"

Friskin cocked their head. "Do not be so sure of their failure, my Lord. For I have seen that the Underground shall not be a prison forever."

That silenced Charlimane in a hurry. As obnoxious as Friskin could be, they had their uses… and chief among them was their insight into the future. Their visions were few and far between, but always accurate, and had proven invaluable time and again. If Friskin had seen the barrier fall…

"The Angel." Friskin's voice was the barest of whispers, dreamlike and ethereal. "The One Who Has Seen the Surface. They shall return… and the Underground will go empty."

Charlimane snorted. "There shall never be one of their kind who sees the surface. They cannot pierce the barrier from within, and no human in their right mind would lower himself to break it from without. There will be no Angel, and the Underground will hold them captive forever." And yet, even as he spoke those words, a cold fist of fear gripped his heart.

"Perhaps not in our time," Friskin replied. "But generations come and go… and what is common knowledge now can be forgotten in time." The bandaged sorcerer shuffled off, thumping their staff into the marble floor with every step, then paused and turned to regard the king.

"Your children, and mine, will never see the day. Nor their children, nor their children's children… but there will come a day when our descendants shall face monster-kind again. And together, they shall determine the fate of this world… and the ultimate future of humans and monsters. So I have seen, and so it shall be done."

"Get out!" Charlimane thundered, slamming the pommel of the True Sword against the arm of his throne. "I will hear no more of your words! Get out and never set foot in this throne room again!"

Friskin bowed deeply and walked out, making their way to the gathering place of their comrades. The human king would live and die believing he had won the ultimate victory… but Friskin had words to pass along to the monster king. Words that, perhaps, could give his kind hope to endure until the prophecy could come to pass. That was all they could do… the rest would be up to the children of the future.