(y/n) panted wildly, bolting as quickly as her legs could take her. The sun was only just starting to come out, so you could barely see her footprints that she left on the forest floor.

However, another creature stomped over hers, leaving behind his own footprints that were at least four times the size of hers.

Without stopping, (y/n) looked back to see the creature was just a few yards behind her.

This only encouraged her to run even faster, shoving tree branch after tree branch out of her way and hoping they slammed into the monster behind her.

They didn't.

Resorting to other measures, (y/n) hurriedly took out the plasma blaster, turned around, and fired.

Unfortunately, the monster dove out of the way, and her shot hit the tree behind him instead. The tree creaked in protest as it started to come down.

Crash!

(y/n) yelped and lunged to the side, softening her landing with a somersault just as the tree landed on the path she had been running on just a few seconds ago.

She turned around, hoping that the creature hadn't been so lucky, only to find the dark purple monster in one piece standing next to the fallen tree.

"Aw, come on!" She screamed in frustration, picking herself up off the ground and continuing to run. The creature chased after her.

(y/n) could barely see much of anything underneath the dark grey sky, but up ahead of her, the little lights of civilization were just starting to come into view.

Almost there.

With all her remaining strength, (y/n) pushed forward, running as fast as her rather short legs could take her. Because of that, she had to take more steps just to keep ahead of the creature.

"Curse you, tiny legs!" She shouted frustratedly, as she started to reach the outskirts of town, where a series of power lines had started.

Her face brightened as a line of fences separating the town from the forest came into view.

But just as she was about to reach them, the monster suddenly swiped his tail at her, knocking her off course and sending her flying into the nearest powerline.

She cried out as the pain spread throughout her body starting at her back, the force of the collision so great that the powerline actually tipped over her motionless body.

Just a few yards away, several residents of Gravity Falls had heard the collision, with Lazy Susan and Mr. Sprott being among them.

"Did you hear that mysterious sound?" Lazy Susan asked in a loud, oblivious voice.

"Sure did" said Mr. Sprott with a laidback and equally oblivious tone. "Sure seems like something we should investigate..."

He started thinking rather deeply about that, contemplating whether or not to actually go check it out.

"Wanna watch this video of my cats getting stuck in the diner coffee machine?" Lazy Susan suddenly asked, holding up her phone.

Mr. Sprott's face brightened.

"Do I?"

And with that, the two of them started walking away, leaving the dangerously low powerline behind them.

(y/n)'s head was throbbing as she struggled to pull herself up, only to see the creature walking towards her, with an ugly smirk across his hideous face.

His low voice chuckled wickedly.

"Well, well, what do we have here?" He said. "The infamous (y/n) Pines. Looking more ragged than the last time I saw you."

(y/n) looked down at her torn clothing. Her shirt was now missing sleeve and had a huge tear across the front, her pants that had so many rips in them that they were really more like shorts with a few patches, and she was missing a boot.

She shrugged carelessly.

"What can I say? I dress to impress my closest monster pals. Now what do you want?"

The monster's red eyes widened with shock.

"Do you seriously not remember me?"

(y/n) thought about it.

"Well, the cliche glowing red eyes certainly don't ring a bell... let me see..."

She pulled a little notebook out of her pocket with the words, "Monsters Who Hate Me and Probably Want Revenge and or Money I Owe Them," written in messy sharpie. She started to flip through several pages.

"Hmm... red eyes, purple skin... are you sure you're a monster, or are you just a really angry man with extreme cyanosis and pink eye? Might wanna get that checked out."

The creature growled vehemently and snatched her throat, lifting her up into the air.

"LOOK ME IN THE EYES!" he boomed. "YOU KNOW VERY WELL WHO I AM!!!"

(y/n) stared at the creature's scarlet eyes, horns, slit nostrils, and sharp bottom fangs that were clearly too large for his mouth with genuine confusion.

"Um, a Venom knockoff?"

The monster growled and squeezed even harder.

"I am Parasite! A monster who can possess your body and make you do things that you don't want to do!"

"Like I said, a Venon knockoff" (y/n) concluded, not seeming to notice the creature's tight grasp around her throat. "What's your weakness? Electricity?"

Parasite snarled like a dog, and brought her closer to him.

"How have you not suffocated yet?"

"Oh, that!" (y/n) said. "I call it the Anti-Choker. You know, cause apparently monsters love holding me up by my neck. I don't know why it's so appealing.

Anyways, you can't really see it underneath those meaty sausages that are probably your fingers, but you're gonna feel a light burning sensation... "

She held up a remote in her hands, and pressed the red button in the middle.

Hiss!

Without warning, Parasite suddenly felt something burn so brightly that a thin orange light started to glow through his hand.

He howled in agony, letting go of (y/n) as he cradled his smoking hand. A new set of words had been burned into it:

'Gotcha, baby!'

(y/n) grasped the former dog collar around her neck, now glad that she had remembered to only make the outside heat up and not the inside.

She then smirked at him.

"Would you like me to sign that?"

Parasite roared in outrage and charged right at her, only for her to leap right over him as he grabbed at empty air.

While airborne, (y/n) dug her feet into his back, and used the force to propel herself upwards, towards a sparkling powerline dangling just a few feet away.

She snatched it in her hands, and as she fell back towards the ground, she aimed the sparking end of the cord right towards Parasite...

"...And that's how I got this scar!" (y/n) finished her story, holding up her arm to reveal a long, red and angry scar running up her forearm. "Oh, and also this angry monster slash normal purple guy with a tail."

She held up a small, enclosed vial with a violet liquid raging inside, crawling up the sides of the glass like frost.

The sounds of a high-pitched outraged screaming echoed from the inside of the makeshift tiny prison.

Nathaniel observed the vial with fascinated eyes.

"A creature that can possess bodies and has sworn vengeance against you? Shouldn't you keep him in a highly secure place instead of a corked bottle in your pocket?"

(y/n) shrugged.

"Eh, I like the sounds of his angry little shouts. They're so cute" (y/n) said, sticking the vial up close to her face and making baby sounds at it.

"Who wants to eat my face? You do! You do!"

Nathaniel looked at the scene with a disturbed expression.

"Do you two need a minute alone?" he said.

"Nah, I'm done" (y/n) said, as she put the vial back into her pocket.

"So, what does Parasite have against you?" Nathaniel asked.

"Oh, he's just another monster I owe money to" (y/n) said. "Along with Droopy ears, unibrow, testosteronus hairificus, and the infamous crime against nature."

Nathaniel shuddered.

"Those sound like some seriously horrific monsters."

"Oh yeah, Stan, Durland, Manly Dan, and Toby can be pretty horrific at times" said (y/n), before turning back towards him. "So anyways, enough about me. What have you been up to lately?"

Nathaniel reclined back casually.

"Oh you know, the usual: eating, sleeping, trying to chew my own leg off" he said, pulling up his left pant leg to reveal the house arrest ankle bracelet. There were several red, angry marks on the skin around it.

(y/n)'s face brightened.

"For real?"

"Very tempting at times, but no" Nathaniel replied. "This idiotic device has started chafing. I tried everything to slip it off, soap, oil, lotion, cologne..."

(y/n) sniggered.

Nathaniel looked back at her, eyebrow raised.

"What?"

(y/n) contained another spurt of laughter.

"Nothing" she said, wiping a tear from her eye. "It's just that... you use perfume?"

"It's not perfume, it's cologne!"

(y/n) couldn't hold her laughter in any longer. Before she knew it, she started chortling hysterically, rolling on the ground and holding her sides.

"It's not that funny!" Nathaniel protested, shooting a hard glare at her.

"Nat, I'm sorry, but are you trying to glare at me now? I really can't take you seriously when you smell like cinnamon and pine!"

Nathaniel groaned exasperatedly, and pulled out a small bottle containing a pale yellow liquid.

"It's Opulence Deluxe by Phil T. Ritche" he explained. "Now selling for $89.99 per bottle."

"So you're a salesman now?" (y/n) asked, finally sitting up.

"No. I'm contractually bound to advertise the brand" Nathaniel admitted. "Along with, Patagonia Clothing! You're not wealthy if you don't have one!"

(y/n) snorted.

"Ha! I make more money scamming monsters and local idiots than you do advertising!"

Nathaniel simply shrugged.

"You might actually be surprised..."

Beep! Beep! Beep!

(y/n) looked down at her frantic watch. She flipped it open, read the alert, and an excited expression flooded her features.

"Sorry, Nat, but I gotta go!" She said, immediately heading towards the window.

"What? But it's only been ten minutes!" Nathaniel protested, getting up off the floor. "And you said last time..."

"I know I promised I'd spend the day with you today, but something popped up."

"Did something happen to Dipper and Mabel?"

(y/n) paused, before making a rather awkward so-so gesture with her hand.

"Not exactly... but I'm getting an alert from a trap that I set up in the forest a couple of weeks ago. I've finally caught the galvanowl!"

Nathaniel looked at her with confusion.

"What?"

"Well, technically, it's a galvan-eagle, but I just thought galvanowl sounded so much better. It's a massive bird made of pure lightning! They're rarely ever seen, and Ford's only seen it once!" (y/n) said eagerly, stepping onto the window ledge.

"I wanna find one so that I can withdraw some of its blood, raw liquid electricity, and use it as a cleaner alternative energy source to power my inventions!"

Nathaniel crossed his arms over his chest skeptically.

"Since when do you care about cleaner alternative energy?"

"Since I found that it's a much better excuse than the sheer impulse of just wanting to catch it" (y/n) replied. "You okay if I duck out early?"

For a moment, Nathaniel just stood there in silence, before finally sighing in compliance.

"I suppose" he said. "Just please don't get fried by a giant lightning bird."

(y/n) tilted her head playfully at him.

"Aw come on. You really think I'm reckless enough to get myself killed and or injured by a stupid sparky bird?"

Nathaniel shot her a concerned, worried expression.

(y/n) sighed, hopped off down from the ledge, and walked up to her best friend.

"I'll be fine. Promise" she said.

Both of them then held up their arms, and rather awkwardly wrapped them around each other before finally letting go in an equally awkward way.

"Best friends hug each other, right?" Nathaniel said quickly.

"Yeah! Yeah! They do!" (y/n) said equally as nervously. "It's all a part of the whole physical reassurance factor only initiated by touch!"

Both of them laughed rather awkwardly, before looking away, refusing to look the other in the eye.

"Let's just agree to never do this again."

"Agreed."

(y/n) climbed up to the window ledge.

"This won't happen again, I promise!"

And with that, she leapt out the window, doing several front flips in the air before landing on the ground like a cat and sprinting off into the distance.

Moments Later

(y/n) was creeping through the bushes, following the tracking device in her hands. There was a blinking red dot on the radar, and the invention seemed to be beeping even more frequently in her hands.

"According to this very non-explosive device, that sucker should be somewhere around..."

She pushed a few bushes aside to reveal a clearing, where there was a bright violet cluster of electricity in the shape of an eagle, trapped underneath a net that had been bolted to the ground.

The creature cawed frantically as it struggled under the tight net, and when it finally noticed her, it hissed ferociously.

(y/n) dropped the device in awe at the sight of it.

"I... I did it..." she murmured, before she suddenly broke out into an enthusiastic victory dance.

"I did it! I did it! I did it!" She screeched triumphantly. "Just wait till Ford sees you—"

She looked up to find that the struggling galvanowl had already pulled one of the bolts out of the ground, and it looked like several more were starting to come loose.

"Better hurry up and collect its blood."

She rushed forward, sliding onto her knees before holding out an extraction device with a syringe jutting out of the end of it.

"Gotta get as many samples as I can before you get loose!"

She had barely filled up the first vial when...

Beep! Beep! Beep!

Her watch screeched in alarm.

She tried to ignore it at first, but the alarm only got louder the longer she did.

She sighed irritatedly as she pulled out the extraction device, pocketed the sample, and looked down at her watch.

It was Nathaniel.

She groaned in an annoyed manner as she flipped it open to answer his call.

"Nathaniel, I already told you, the watch line is for emergencies only—"

"(y/n), you've gotta come back" Nathaniel's panicked voice said through the watch. "There's been a breach! An imposter is attacking the manor right now, and I suspect he's been posing as one of the staff! He's getting pretty close to my hiding spot. I don't know how much longer before he finds m—"

The signal went dead before he could finish his call.

Behind her, the galvanowl had torn through the last of the bolts, and was now flying free. With a flash of lightning, it had vanished without a trace.

But the galvanowl was the least of (y/n)'s worries now.

She looked back towards Northwest Manor, which was several hundred miles away in the distance.

"Nathaniel."

Seconds Later

A bright purple portal opened up right next to the mansion, and (y/n) bolted out of it. The portal closed behind her.

The instant she was out, she threw her tablet to the ground, and it converted itself into her hoverboard.

She leapt onto it, and directed it to fly her all the way to Nathaniel's closed window.

Without warning, she smashed right through the glass, shards flying in all directions as she leapt off the hoverboard.

(y/n) pulled out the plasma blaster and aimed it forward, the end starting to emit a threatening blue glow.

"Alright, you freak, why don't you pick on somebody your own size?" She yelled fiercely.

But there was something in the room that caused her to nearly drop the weapon. Her face flooded with absolute horror.

The floor was stained with a dark crimson liquid, which trailed all the way out from under the bed, where there were a pair of familiar legs sticking out in an unnatural way, more liquid pouring out from underneath them.

(y/n) was going to be sick. She felt a mixture of horror and her breakfast resurfacing as she painfully made her way towards the bed.

"N-Nat?" she stuttered.

Suddenly, a pair of arms grabbed her from behind, pulling her into a nearby closet.

(y/n) screamed and kicked savagely.

"G-get back, you... you..." she stuttered angrily, her voice dripping with so much fury that she couldn't even make out a full sentence.

"(y/n), it's me" said a familiar voice, as the closet light flickered on.

She turned to face the source of the voice, who was none other than Nathaniel.

"You know, the window was unlocked."

That remark was met with a direct punch to the gut.

He reeled over in pain, clutching his stomach painfully.

"What the heck was with that?!" (y/n) exclaimed agitatedly.

Nathaniel hurriedly put his hand over her mouth.

"Shh shh" he whispered as he put his ear against the closed closet door. He didn't remove his hand.

They could hear the sound of soft, muffled footsteps approaching, before they suddenly stopped.

It sounded like the intruder had paused to look inside Nathaniel's room, only to find the horror scene that (y/n) had walked in on.

The pause lasted for what seemed like a century before they finally started again, becoming softer as they got further away.

They both breathed a sigh of relief.

Nathaniel finally lowered his hand.

"I'm awfully sorry about... what you saw, but I had to find some way to get the imposter to leave me alone" he apologized.

"What did you use for the blood?"

"... Jam, but that's not important" Nathaniel said. "Now that you're here, we can subdue the intruder before he hurts someone else."

"AAAAAAAHHHH!!!"

The two of them practically tore the closet door off of its hinges as they bolted towards the source of the screaming.

"That sounded like my uncle!" Nathaniel said worriedly, as they indeed approached Preston's white room.

There were a few white tables and chairs that had been flipped over, and the pale bed had been pushed against the wall, but Preston wasn't there.

"No..." Nathaniel murmured, before (y/n) hurried forward and snatched a note off the floor.

'Give up the entire Northwest family fortune to me in the atrium within twenty four hours, or Preston Northwest dies.'

"Now that's just dumb" (y/n) said. "He already has the guy who owns all the money. Why threaten to kill him?"

"Uncle Preston only has half of the family fortune, remember?" said Nathaniel. "My father has the other half, and I'm assuming that the imposter wouldn't bother to fly all the way to the UK if his son is already right here."

"Then you really gotta beef up the security around here."

Nathaniel's eyes suddenly widened with realization.

He sprinted out of the room.

"P.I.N.E.S, activate lockdown security measures!" he yelled.

(y/n) watched as the gate surrounding the manor suddenly started to glow orange.

Zing!

A wall of energy was shot up from all sides, converging at the very center at the top.

In less than a second, the entire mansion was contained inside an orange force field.

(y/n) observed it, clearly impressed.

"Voice activated force field? Since when did Northwest Manor have that?"

"Since the little ghost incident a few weeks ago"