Harry Potter and the Ambitious Girl

It was 2 a.m., a time when all the students were sound asleep.

Amid the silence, a group of 11-year-old boys and girls were risking everything to protect the Philosopher's Stone hidden within the school. Despite their youth, they threw themselves into the heart of danger to thwart the dark lord's ambition of resurrection.

They put the three-headed dog to sleep, navigated a devilish trap, and identified the real key among countless fakes.

Harry's friend made the ultimate sacrifice in the chess room to allow the others to proceed, while Hermione, surrounded by flames, kept her cool and ensured Harry could continue.

Harry himself, battling the fear of encountering the dark lord ahead, pressed forward alone.

All of this was to keep the Stone out of the dark lord's clutches.

But what they didn't know was that their every move had been observed—by a single rat.

Ever since they opened the hidden door, the rat had been tailing them unnoticed.

"...The time is near…"

The rat's surveillance was relayed to the other mice in the school through a sort of telephone game, finally reaching Pyotr, Mirabel's pet.

From this, Mirabel deduced the situation. She had spent a year building this network of rats.

Of course, Mirabel couldn't actually understand the rats' language. However, this world had a convenient magic called "Legilimency," which allowed one to read thoughts and memories.

Using this, it was easy for her to grasp Harry's group's situation by reading Pyotr's mind.

"Pyotr, is Dumbledore nearby?"

"Squeak!"

"Not yet… Then let's make our preparations while we can."

If her knowledge was correct, Dumbledore would return to the castle by the time Harry obtained the Stone.

But that wouldn't do. At the very least, Dumbledore needed to be delayed until she had the Stone in her hands.

"Pyotr, mobilize all the mice in the school to stall Dumbledore. Barricade the gates, and enlist Peeves. Use any of the gadgets I bought from the prank shop if necessary."

"Squeak!"

"Good. Go."

With Pyotr off to hinder Dumbledore, Mirabel stood up.

Although the mice were tasked with the delay, it wouldn't hurt to set a few traps of her own. After all, her opponent was the greatest wizard of the century—there was no such thing as being too cautious.

Using Apparition, she vanished and reappeared instantly in front of the fourth-floor hallway, opening the door and stepping inside.

She closed the door behind her and raised her wand.

"Colloportus! Seal the door!"

She cast the Locking Charm, firmly securing the door.

Of course, Dumbledore would likely dispel it in an instant, but this was only the beginning.

"Grrr…"

"A three-headed dog… You'll serve me well."

Before the snarling Cerberus, ready to attack, Mirabel took out a flute.

She played a soft, flowing melody that immediately subdued the beast.

Music was the dog's weakness, and the sound lulled it into submission before long, leaving it vulnerable. Seizing the moment, she quickly pointed her wand at its nose.

"Imperio! Obey me!"

A forbidden mind-control spell that bent its target to the caster's will. A spell so illegal that its use on humans would result in immediate imprisonment in Azkaban.

Yet the young girl cast it without hesitation.

Her goal was, of course, to turn this dog against Dumbledore.

But music remained the dog's greatest weakness, so Mirabel added another layer of magic.

"Muffliato! Muffle the ears!"

A spell that caused constant, irritating noise to resonate in the ears of its target.

Now, the three-headed dog would hear nothing but static. Even if someone tried to play music, it would be drowned out by the noise.

With its weakness eliminated, the dog was now an unstoppable force. Not even Dumbledore would have an easy time pacifying it.

"Serpensortia! Summon snakes! Avis! Birds, attack! Oppugno!"

From her wand came a swarm of snakes that covered the floor and flocks of birds that filled the air, fortifying the defenses.

Should Dumbledore break through the door, he would face simultaneous attacks from the three-headed dog, the snakes, and the birds.

Even Hogwarts' staff would struggle to overcome such a layered defense.

And yet, Mirabel remained vigilant.

This setup would likely buy her 20 minutes—no, perhaps only 10.

But that was more than enough to defeat Quirrell and seize the Stone.

"It's about time Potter got the Stone."

With a murmur, she vanished once more, instantly teleporting to the inner chamber where the Philosopher's Stone was hidden.

"Kill him! Kill him! Kill him!"

The chilling cries echoed through the innermost chamber.

Hearing such a terrifying voice, most wizards would have frozen in fear or fled in panic. After all, it was the roar of none other than Voldemort—the Dark Lord whose name had once struck terror across the entire wizarding world.

But Harry did not run.

Clinging tightly to the arms of Quirrell—the wizard serving as Voldemort's host—he fought desperately to keep the Stone out of his grasp.

The difference in power between them was obvious. Harry could never hope to defeat Quirrell.

Yet something inexplicable protected him. Quirrell couldn't lay a hand on Harry.

Every time he tried, his skin sizzled, his flesh burned, and excruciating pain seared through his mind.

Realizing this, Harry clung to Quirrell's arms, using the agony to stop him from moving.

"Kill him! What are you doing, you fool? It's just a boy!"

Voldemort's furious commands resounded ceaselessly from the back of Quirrell's head.

There, Voldemort's horrifying face was parasitically attached, shouting in rage.

Despite this, Harry fought to remain conscious.

The scar on his forehead throbbed with unbearable pain, and his vision darkened.

But he refused to let go because he loved this school—loved everyone in it.

If Voldemort were to return, the school would be the least of their worries. Everything would be destroyed.

His friends Hermione and Ron, the strict but kind teachers, his fellow Gryffindors, Hagrid—everything and everyone would be lost.

Harry couldn't allow that. To him, this school was a home, and he wouldn't let it be ruined.

This determination alone drove the 11-year-old boy to keep fighting.

But eventually, his consciousness began to fade.

The screams of Quirrell and the shouts of Voldemort grew distant, and everything dissolved into a dreamlike haze.

Just before he lost consciousness completely, Harry thought he heard it—a high, bell-like voice.

A golden flash erupted, striking Quirrell directly.

The blast hurled him away from Harry, separating them by a significant distance.

Quirrell knew this paralyzing attack. He had suffered it before in the forest when he tried to drink unicorn blood.

And he knew the terrifying golden-haired girl responsible for it.

"Well, Professor Quirrell. It seems Potter gave you quite a hard time."

"M-Mirabel Beresford…"

She was the fearsome girl who had overwhelmed him despite being only a first-year student.

Her readiness to cast Unforgivable Curses without hesitation made one question if she was truly just 11 years old.

Now, the terrifying golden-haired girl stood before him once more.

Unconsciously, Quirrell took a step back, sweat dripping from his forehead.

Ignoring her cowardly foe, Mirabel turned her gaze to Voldemort.

"So we meet at last, Voldemort. Quite the fashionable look you've got there."

"…A comrade of Harry Potter's, are you? Here to meddle again…"

"A comrade? Me?"

At Voldemort's misguided remark, Mirabel let out a soft laugh.

True, Harry had been a useful ally in obtaining the Stone.

She had provided him with information and even saved him once.

In that sense, one might indeed see her as his comrade.

"Well, I suppose… Potter was incredibly helpful.

He cleared all the obstacles, dragged you out into the open, and even secured the Stone for me.

But that's all. I have no further use for him."

"…So, you're not here to save him?"

"Of course not. What happens to him is none of my concern.

My goal has always been the Philosopher's Stone."

Smiling with a chilling calmness, Mirabel drew her wand from her cloak.

Quirrell instinctively took another step back, widening the distance between them.

"I see… Then join me."

"…Oh?"

"You are a gifted witch and come from a pure-blood lineage.

If you side with me, I'll grant you the benefits of the Philosopher's Stone. It's not a bad offer, is it?"

"…"

Voldemort's proposal was met with silence from Mirabel.

Perhaps interpreting her lack of response as a sign of interest, Voldemort continued.

"It would be a waste to let such talent go unfulfilled. If you join me, you could become even stronger."

"…"

"You would make an excellent Death Eater—far more fitting as my servant than this pathetic Quirrell."

"…"

"Surely, even a girl like you has no reason to refuse such an offer."

"...Heh... Heheheh… Hahahahaha…"

Mirabel let out a small chuckle at first. But the laughter grew louder and louder, until it burst forth uncontrollably.

Unbelievably, the girl began to laugh uproariously, her voice echoing through the chamber, even as she stood before the feared Dark Lord of the wizarding world.

"Ahahahahaha! HAHAHAHAHAHAHA!"

Had anyone ever shown such audacious disrespect toward the Dark Lord?

It was far beyond mere arrogance.

"What's so funny?!" Voldemort roared, finally cutting off her laughter. Mirabel locked her gaze on him.

"Heh... It's funny, Voldemort. You don't understand at all.

What I seek isn't the Philosopher's Stone. My true goal lies elsewhere."

"What…?"

"Let me enlighten you. The thing I desire more than the Stone is…"

Mirabel's grin twisted into something feral, her sharp teeth flashing.

She was about to strike!

Quirrell, without fully understanding why, felt a surge of alarm and reflexively raised his spare wand.

But before he could act, Mirabel was suddenly in front of him, just as she had been in the forest.

"...Your life!"

"!"

She swung her wand, crafted from over 70 centimeters of vampiric wood, striking Quirrell hard in the stomach.

With a seamless motion, she pointed the wand at him and shouted her spell.

"Diffindo! Rend!"

"Sectumsempra! Sever!"

Two slashing spells collided mid-air, canceling each other out.

Quirrell launched the next spell faster this time.

"Aguamenti! Water, come forth!"

"Glacius! Ice, freeze!"

Mirabel countered his water spell with an ice-freezing incantation, turning the stream into solid ice.

She then shattered the frozen water with her wand, sending sharp fragments flying back at Quirrell.

Stunned by the unexpected reversal, Quirrell hesitated for a moment.

Mirabel didn't let the opportunity slip.

"Expelliarmus! Disarm!"

A red flash erupted from her wand, disarming Quirrell and sending his wand flying.

Though a basic spell, Expelliarmus is highly valued for its simplicity and effectiveness. In duels, disarming an opponent's wand often all but guarantees victory.

Now defenseless, Quirrell found himself at Mirabel's mercy as she pulled out a second wand from her sleeve.

It was none other than Quirrell's original wand, which she had taken from him during their earlier confrontation in the forest.

The wand he'd been using now was just a substitute, likely stolen from another wizard.

"I've brought back something you left behind, Professor Quirrell."

"N-no, please…"

"Take it… Priori Incantatem! Reenact!"

The wand in her hand recreated its most recent spell—none other than the Cruciatus Curse, one of the Unforgivable Curses.

The curse struck Quirrell directly, tearing through his nerves with excruciating pain.

"AAAAAAARRRGGHHHH!!!"

"Hahaha! What a lovely scream, Professor Quirrell! Makes bringing this back all the more worthwhile!"

The former teacher writhed in pain on the floor, and Mirabel drove her foot into the back of his head—more specifically, into Voldemort's face.

Grinding her heel mercilessly, she trampled on the feared Dark Lord as if he were nothing more than roadside trash.

The contorted expression of frustration on his face was utterly delightful. Seeing him consumed by humiliation brought Mirabel a twisted sense of satisfaction.

She was trampling on the man whose very name inspired terror in all, the man no one dared to speak of.

"Well, well, how does it feel, Voldemort? To be made to lick the boots of a girl like me?"

"Y-you... insolent wretch…"

"Heh… Your era is over, Voldemort.

The world is moving forward, leaving behind the old ideals of pure-blood supremacy. There is no place for you in this new path."

To be honest, Mirabel wanted to savor Voldemort's anguished cries a little longer. However, she couldn't afford to waste too much time—if she delayed, Dumbledore might arrive.

With that in mind, she decided to wrap things up quickly. Raising her wand, she declared with unwavering confidence:

"Remember this humiliation in your very soul! My name is Mirabel Beresford!

I am the one who will sweep away the old ways of wizards like you and build a new world!"

From her raised wand emerged a monstrous creature over ten meters long, formed of golden, blazing fire.

It was both beautiful and terrifying—a beast with nine heads extending from its serpentine body, eyes slit vertically, and razor-sharp teeth.

A dragon-like creature from myth, known as the Hydra.

This was a manifestation of Fiendfyre, the highest-tier offensive spell, requiring immense magical power and skill to wield.

For anyone lacking mastery, such flames could spiral out of control, leading to self-destruction. But Mirabel wielded it effortlessly, a testament to her prowess.

The fiery Hydra lunged at Quirrell!

"AAARGH! IT'S HOT! IT'S BURNING—!!"

Quirrell screamed as the flames engulfed the back of his head, rolling on the ground in a futile attempt to extinguish them.

But Fiendfyre is a cursed flame—it does not go out until its target is completely consumed or the caster extinguishes it.

Voldemort, however, suffered far worse. With his face ablaze, the agony he endured was unimaginable.

His screams eventually fell silent, leaving only Mirabel's triumphant laughter echoing through the room.

"Hahaha! How does it feel? Is it unbearable?

This must be your first taste of true pain, Voldemort! Hahaha!"

Unbeknownst to Mirabel, Voldemort had split his soul into Horcruxes, making him incapable of dying.

Yet even for him, this was a torment worse than death.

Seeking escape from the pain, Voldemort abandoned Quirrell's body, retreating as a disembodied soul.

Though leaving the Philosopher's Stone behind was a bitter loss, knowing when to retreat was a skill in itself.

Carrying this humiliation deep within, Voldemort fled without a word to his utterly useless servant.

It was the second great defeat of his reign as the Dark Lord, the first being his encounter with Harry Potter.

With no target left, the Fiendfyre dissipated. Mirabel narrowed her eyes, puzzled.

"…Hmm? Voldemort disappeared? Did he run away?"

"Aah! Master! Where have you gone, leaving me behind?!"

All that remained was the pitiful man Voldemort had discarded, looking frantically around like an abandoned dog.

To be forsaken in the presence of such a terrifying girl meant there was no hope for survival.

Quirrell's desperate search for his master ended when his gaze met Mirabel's.

Her cold stare sent him reeling with fear, and he let out a gasp.

"Abandoned, huh… How pitiful."

"Eep!"

"Well, consider this an act of mercy. I'll send you off without making you suffer any further."

As Mirabel aimed her wand, preparing to conjure Fiendfyre once more, Quirrell's reaction was immediate—he prostrated himself on the ground.

Unconsciously adopting the gesture said to demonstrate ultimate respect in Japan, Quirrell groveled and pleaded tearfully before the eleven-year-old girl.

"P-please don't kill me! I beg you! I'll serve you! I'll do anything you say!

I'll be your errand boy, your shoe polisher—whatever you want! Just spare my life!"

"…Such ingrained servility…

I suppose a man who submitted to Voldemort's terror would end up like this."

Frankly, taking a man like this under her wing offered no real benefit.

Sure, he had some level of competence—his skill with trolls, for instance, was notable.

But this was the kind of man who would inevitably betray her. A man who switched allegiances out of fear would just as easily do so again if faced with a greater terror.

Yet, as Mirabel thought it over, a malicious smile crept onto her face.

Ah, yes… there was a certain spell that would suit such a man perfectly.

"So, you mean to say that after serving Voldemort, you'll now degrade yourself to being my tool?"

"Y-yes! A tool, a pet—anything you wish! Just please, spare my life…"

"Very well. I grant you permission to serve me."

Quirrell's face lit up with hope at her apparent mercy, but that expression would soon twist into despair.

He still didn't truly understand the nature of the girl before him.

Mirabel wasn't merely a ruthless individual—she derived immense pleasure from stepping on others, causing pain, and admiring their anguish. Quirrell had yet to grasp this fundamental truth about her.

Before his eyes, Mirabel pulled out a bat wing and burned it in her hand.

The flame turned blue and was absorbed into her fingertips. What happened next was even more bizarre—her nails turned blue and began sprouting small, writhing tendrils like miniature tentacles.

Watching the eerie sight, Quirrell timidly asked, "W-what… what are those claws?"

"Oh, just a little spell to prevent betrayal. It's a spell I created based on some very particular knowledge…

These blue claws will burrow into your body, spreading roots throughout and parasitizing you.

Should you defy me, or even attempt to sever these claws, they'll shift in color—from blue to purple, and finally to red."

So, the claws' color would reflect his level of obedience?

Quirrell found it terrifying but somewhat reassuring—at least it seemed straightforward.

Betrayal was out of the question. If he even entertained such thoughts, the unmistakable proof of his disobedience would appear in the form of crimson claws.

It was a subtle yet terrifying spell.

Still, Quirrell underestimated Mirabel.

Why would she use something so mild in a situation like this?

"When these claws turn crimson, like fresh blood, it will mark your end.

Your body will shatter into fragments, and each tiny piece of flesh will 'transform.'

You'll become mindless, powerless vermin."

"W-what… no, no!?"

At last, Quirrell realized the gravity of his mistake.

There truly were fates worse than death in this world.

And this, without a doubt, was one of them.

To be reduced to a mere insect, unable even to die—it was far crueler than simply being killed.

Grabbing the panicking Quirrell by the neck, Mirabel drove her claws mercilessly into his arm!

"Clavis Servus! The Slave's Claw!"

"Gaaahhh—aaaaghhh!"

The blue claws extended from Mirabel's fingers, burrowing into Quirrell's body and crawling up to embed themselves in his index finger.

From this moment on, Quirrell could no longer defy Mirabel. Technically, he could—but doing so would mean becoming an insect.

If he wanted to avoid that fate, he would have to devote himself to her completely and indefinitely.

It was a spell of forced obedience so brutal that even the Unforgivable Curse Imperius seemed merciful in comparison.

"H-heek… n-no… this can't be…"

"Now then… I think it's time for you to disappear for a while."

From her breast pocket, Mirabel pulled out a miniature display cabinet and cast an enlargement spell to return it to its normal size.

It seemed this shelf, which Holger had gifted her, would now serve its purpose.

With tears welling in Quirrell's eyes, Mirabel grabbed him by the head, kicked his back, and shoved him unceremoniously into the cabinet.

"This connects to my family's villa on Magnolia Crescent.

It was something my father built on a whim, but it's been unused for years. It's a perfect place to hide."

"Y-yes… understood!"

Following Mirabel's instructions, Quirrell disappeared into the display cabinet.

His obedience was unusually prompt—likely because he was desperate to get away from Mirabel as quickly as possible.

After shrinking the display cabinet back to its miniature size, Mirabel tucked it into her pocket.

(It would've been easiest if Quirrell could take the Stone out of here for me… but there's a chance he might use its power to break my curse.)

Although Quirrell had become a useful pawn, handing him the Philosopher's Stone posed a grave risk.

Her curse ensured betrayal would result in his transformation into a vermin far more quickly than any attempt to break it, so she wasn't worried about ordinary methods. But the Philosopher's Stone was an exception.

With the Stone, Quirrell might be able to undo the curse before his body shattered—or even reverse the transformation if it had already occurred.

For this reason, she couldn't entrust him with the Stone.

"Well, no matter… once I leave this place, it'll all be over. In the end, it was I, Mirabel, who had the last laugh."

She glanced at the clock.

Only four minutes had passed since she arrived. She still had six minutes left before she expected Dumbledore to show up.

Even if Dumbledore arrived at double the speed she anticipated, it wouldn't have been fast enough to stop her.

With a faint smile, Mirabel approached Harry's unconscious form and took the Stone from his hand.

Her objective was complete. The battle had been surprisingly effortless.

"Heh… perhaps I could have spared another minute or two for some fun."

"No, Mirabel… your time's up."

…!!

The voice behind her froze her thoughts for a moment. She turned around instantly.

Standing there was an elderly wizard, cloaked in emerald robes.

Behind his half-moon glasses, his sparkling blue eyes gleamed with intelligence, and his crooked nose bent in multiple places.

His silver beard, so long it reached his waist, was tucked into his belt.

(…Impossible… It hasn't even been five minutes…!)

She had blocked the castle gates, laid traps everywhere, and even mobilized Peeves to stall him.

Inside the chamber, she had set up serpents, birds, and a three-headed dog, going as far as eliminating its weaknesses to ensure absolute preparedness.

She hadn't underestimated Dumbledore. In fact, she had fully accounted for his immense skill, estimating it would take him 20 minutes to arrive. To be safe, she halved that estimate to 10 minutes.

Yet here he was, breaking her timeline in half again.

Why? How?

Apparition? Impossible! This area prevented such magic.

Granted, Dumbledore could likely break through the anti-Apparition spells surrounding the school, but such an act would've alerted her. There were no signs of that!

"Breaking through your traps was quite the ordeal… Truly, you have a terrifying talent," Dumbledore said.

"…Why, Headmaster Dumbledore, you're here rather quickly," Mirabel replied, masking her shock.

"Indeed… I hurried back out of concern for Harry. Imagine my surprise to find that Voldemort had already been defeated. Remarkable work… and yet…"

Her eyes narrowed as her mind raced.

She had thought her assessment of his power was more than adequate, but it was clear now that she had vastly underestimated him.

To have misjudged his abilities so drastically—by more than half, perhaps even by a quarter—was an unforgivable mistake.

Now she understood. If this was the man Voldemort feared, it made perfect sense.

He deserved every ounce of the respect wizards and witches held for him.

"Now, Mirabel, would you kindly hand over the Stone? It's not something that should be in your possession."

So this is Albus Dumbledore… the greatest wizard of the century…!

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