"Oh my god, this attic is amazing! Look at all my splinters!" Mabel cried, turning away from her poster of a dreamy boy to show her bark-covered fingers to her twin brother.

Mason shook his head, smiling fondly at her antics. "Mabel… C'mere, I'll help ya take 'em out."

"Aw, but I like my splinters! It's, like, a memento of my first day in Gravity Falls! Can I keep 'em, Dipper? Please please pleeeeease?"

Mason wasn't going to give into her puppy-eyes, though. "You can put them in a jar, alright? Ya can't keep your hands like that, though- it's a bad idea to walk around with open wounds in a forest."

Mabel heaved a hefty, put-upon sigh. "Ugh, fine. You're such a dork, Brotato."

"Yeah? Well, you're such a Mabel."

"...Did you just use my name as an insult?"

"I'm sure I packed tweezers somewhere…"

"Not cool- oh, hello, Mr. Goat!"

Mason wasn't really sure how he ended up here, a few hundred miles North of home in the rickety old Mystery Shack of Gravity Falls, Oregon. He was pretty sure it had something to do with getting into his twelfth… No, make that thirteenth fight of the school year. That was back in November. Now, in late June, that number had nearly tripled. November was just when his parents had decided enough was enough, and that no matter what he did, Mason would be shipped off to spend the summer with his Great Uncle, Stanford Pines. Mabel only tagged along because she wanted to- and, Mason was absolutely not leaving her alone in that house.

In his defense, though, Mason was not the one to start any of those fights. He never was. It all began back in elementary school, when some kids thought it would be fun to pick on chipper little Mabel, with her rainbow braces and even more colorful personality. By that point, Mason was already used to protecting her from their mother, so he leapt into the fray without hesitation. However, he realized that fighting back against other kids was a lot different than fighting back against adults. Namely; Mason actually won those fights.

That, obviously, didn't sit well with the other kids, who came back for seconds. When it was served up, hot n' ready, they came back a third time, with one of the kid's older brother and his friends. Mason still beat them, somehow. It was either an act of God, or those fifth graders were just horribly unfit, but little third-grader Mason still put them in place. That was when his reputation, his legend, began.

Pretty soon, the challengers were lining up. Mason did his absolute best to ignore them. They insulted his height (not really an issue anymore, now that he was mere centimeters short of six feet), his constellation-shaped birthmark (which he covered with his choppy bangs), his lack of friends (people didn't exactly wanna run the risk of being collateral just to hang with him), his nerdiness (meaning they were just jealous that he got better grades than all of them), but when they started going after Mabel, that's when the fists started flying. Occasionally, there would be the brave soul that skipped the whole ordeal, and went straight to trying to punch him in the face. Mason left the fewest injuries on them, because at least they had decency.

Come sophomore year of high school, pretty much everyone in Piedmont knew about him. Mason Pines, the kid that lived to brawl. Upperclassmen trying to look cool in front of their crushes, incoming freshmen thinking they were the hottest thing on the block, wannabe-thugs who wanted to cement their status as the top dog- Mason had to deal with all sorts of people throughout the years. Honestly, he was just tired of all the fighting.

Of course, he couldn't very well stop. The world wasn't that nice. So, in freshman year, Mason searched the high school's club directory, and found the perfect one; boxing. The coach wasn't impressed with him- a scrawny little brat who averaged a fight a week for nearly six years? It was a surprise Mason wasn't thrown out on his ass immediately after the man learned about his escapades. Apparently, he managed to surprise the man with his impulse control. According to every single one of his reports- and there were many, Mason was honestly shocked Coach McFist went through and read all of them- Mason had never thrown the first punch. Even when those kids were talking all that smack, yelling in his ears, shoving him around and getting all up in his face, he would stand there, arms crossed, in front of Mabel. Like a stoic bulwark, shielding her from the dark underworld of public schools.

McFist liked that. He also liked that Mason was top of his class. So, he gave the boy a chance, and allowed him into the club. Even though there were at least a dozen other members, Coach McFist focused almost solely on Mason. The rest were left to the mercies of the assistant coach, whose name Mason never bothered to learn. When classes ended for the day, and kids were going to their afterschool programs, it was just Mason and McFist. Teacher and student.

If those fools thought Mason had been vicious before, they were wetting themselves by the end of freshman year. He never used what he learned in boxing against the other kids- that was a guaranteed way to get him booted from the club, and just straight up disrespectful to Coach McFist- but the conditioning alone was enough to make him an absolute beast. His speed, agility, footwork, strength. Nobody could lay a hand on him, but they could sure catch his.

The jury was still out on whether the end result- being sent to Gravity Falls- was a bad thing or not, but there was one thing that Mason was sure of; it was definitely worth. He'd do it all again in a heartbeat, if it meant protecting Mabel.

"He's looking at it, he's looking at it!" Mabel whispered, peering over one of the shelves to stare at a boy. Said boy had a piece of paper in his hand.

"Do you like me," he read, "Yes, absolutely, or... Definitely?"

"I rigged it," Mabel told him quietly. The kid dropped the letter, wiped his hands on his jeans, and made a hasty escape from the Mystery Shack. He probably wouldn't be back. Mason had taken a pause from polishing a jar of eyeballs to watch it go down.

"Uh, May, I get that you're going through your whole boy-crazy phase, but don't you think you should tone it down with the crazy part?"

Mabel turned towards her twin, blowing him a raspberry. "C'mon, Dip-Dop! It's our first summer away from home! It's my only chance to have an Epic Summer Romance~!"

Mason rolled his eyes. "Yeah, yeah. Get back to cleaning- if we finish early, Stan'll let us out for the afternoon. Maybe you'll have more time to pursue your epic romance."

Mabel slapped her hands to her cheeks, gasping in awe. "Dipper, you're a genius! I'mma clean this place so sparkly-shiny, Grunkle Stan's gonna say, Mabel, you don't have to clean the Shack ever again, and then I can chase boys for the whole summer!"

"Um… Sure?" Mason turned back to the eyeballs. "Hope these things aren't real. Then again, considering Stan's the one who got it…" he muttered. One of them blinked, and Mason backed away slowly, fighting down the urge to spew chunks. "Nevermind. I think I know now, and I really wish I didn't."

The man himself emerged from the back of the shop, attempting to burp. "Oh, that's not good." He slammed a fist against his chest a few times, belched loudly, then sighed in relief. "Mason, I need you to go out into the creepy part of the woods and hammer up these signs!"

Mason sighed, handing Mabel his spray bottle and rag, switching it for the bedazzler she'd mysteriously conjured up. He handed it to the redhead at the desk, Wendy. A girl a year older than the Pines twins, who was less likely to use it on absolutely anything in her vicinity. "Right. You mean the creepy part, or the creepy part?"

"The creepy part."

Mason dragged a hand down on his face. "Stan, you know how much that place freaks me out."

"I know- That's why I'm sendin' ya there! Ha!" Stan shoved the arrow-shaped signs into his hand. "Now hurry up- I'm not payin' ya to stand around all day."

"Stan, you're not payin' 'em at all," Wendy chortled.

"That's the best part!" the old man cried happily. He slapped Mason hard on the back. "Get to it. There's a hammer and a bucket of nails somewhere out back."

CLANG

Mason jumped back in shock. "What the hell?" he cried. He glanced at his hammer, then back at the tree. It looked like a normal tree, but…

CLANG CLANG

It sounded like it was made of metal. Why would there be a completely metal tree in the middle of the forest, designed to perfectly blend in with its surroundings? Well, there was a reason they called this place the creepy part of the woods. Mason ran his hand over the steely bark, and found a little notch in the otherwise smooth surface. He dug his fingers in a bit, and had to tilt back to avoid getting knocked in the head when a compartment swung open. Inside was a bunch of cobwebs, and a dusty old radio.

"The heck…?" Mason flicked the two switches on top, not really expecting it to work. He also didn't expect to hear a mechanical whirring behind him. He spun, fists up, ready to punch anything that came at him, but there was nothing. Instead, Mason saw a hole in the ground- one that hadn't been there just moments before. It was perfectly square. Definitely man-made.

A goat had been chomping the grass right over the hole, and was scared off by the sudden noise. Mason vaguely recognized it as the one that had been on his bed when he'd first entered the attic of the Mystery Shack.

"Sorry, Gompers," he muttered absentmindedly, creeping towards the hole. Mabel had been the one to name it, of course. Inside the compartment was what looked like a book. It was caked in dust and wrapped in cobwebs. A few insects scuttled out of the hole. Hesitantly, Mason reached towards the book, ready to snatch his hand back if, say, the compartment snapped shut, or something underneath the book tried to bite his arm off. Mason sighed in relief when nothing happened as he picked up the book. He turned it over in his hands a few time, blowing and brushing the grime off it, to reveal a gold-inlaid handprint on the front. For some odd reason, it had six fingers. The number 3 sat in the middle of the print, black and bold.

"Whoa…" he breathed, opening the hardened leather cover. He was gentle while turning the pages- no telling how old this thing could be, and paper got super brittle after a few decades. There was a looking glass tied to a string, which was attached to the inside of the spine. On the next page, a note of some sort.

"It's hard to believe it's been six years since I began studying the strange and wonderous secrets of Gravity Falls, Oregon…" Mason flipped the page, and threw caution to the wind, turning the possibly-fragile paper faster and faster. "Floating eyeballs, giant vampire bats, gnomes? What is all this…?"

A new note.

"Unfortunately, my suspicions have been confirmed; I'm being watched!? I must hide this book before he finds it. Remember, in Gravity Falls, there is no one you can trust." Mason slammed the book shut, ignoring the cloud of dust that exploded into his face. He was too busy trying- and failing- to fight off the shiver that ran down his spine.

"Being watched…" he muttered, glancing around the forest. Suddenly, the shadows seemed too dark, the trees too close together, the silence too ominous. Mason shuddered again, and tucked the Journal into the massive pockets inside his sweater vests. He hammered the last sign in quickly, not even caring that the nail bent and the arrow was pointing the wrong way, and booked it back to the Mystery Shack.

Mason was sitting on the couch in the living room, hours later, flipping through the Journal. Stan walked into the room, and Mason froze. He couldn't just put the book away- the old man had already seen it, and it would be too suspicious. No, he had to play it cool. Mason casually crossed his legs, resting his right ankle on his left knee, and tilted the book down so the cover was hidden in his shorts.

"Whatcha readin' there, slick?" Stan asked, taking a sip of his Pitt Cola.

Mason glanced up at Stan, acknowledging his presence, before turning back to the Journal. "Ya know- nerd stuff."

Stan chuckled. "Yeah, your parents told me 'bout your grades- most likely to be valedictorian in your year, they said! That, and you're a champion scrapper. Ya got the best a' both worlds, kiddo."

Mason shrugged. "Honestly, I could do with a bit less of the scrapping."

The doorbell rang, and Mabel rushed down the stairs. She was wearing one of her brighter colored sweaters, her skirt was bedazzled- was that lip gloss? She opened the door, and turned to the males in the living room.

"Grunkle Stan, Dipper, I'd like you to meet my new boyfriend!"

The dude was wearing a black hoodie, zipped all the way up despite the summer heat. The hood was covered in twigs and leaves, like he'd had just ran a marathon through the forest. His cheek was splattered with something red. He raised a hand, giving Mason and Stan a wave.

"'Sup," he said.

Mabel grabbed his arm. "We met at the cemetery- he's really deep," she said, staring up at him dreamily.

Mason narrowed his eyes at Mabel's new boyfriend. "So, what's your name?" he asked, trying a bit too hard to be casual. His voice accidentally came out as a growl.

The dude's eyes began darting every which way, and his voice was shaky when he answered. "Normal… Man!"

"He means Norman," Mabel covered, acting as if that wasn't the most suspicious thing in the world.

"Right. Norman," Mason muttered, voice dripping with sarcasm. He pointed at the dude's face. "Are you bleeding, Norman?"

Norman quickly wiped away the red dripping down his cheek. "It's jam!" he said, unconvincingly. Mabel seemed to buy it, however.

"Oh my god, I love jam!" she squealed.

"So, you wanna go, hold hands, or whatever?" Norman asked, looking for any excuse to get out of there.

Mabel held up a hand to her mouth, seemingly scandalized. "Oh. Oh my goodness," she whispered. "Don't wait up!" she cried, and nearly ran out the Shack. Norman followed, swaying unsteadily, slamming into the wall every now and then. Mason and Stan watched the two go, then glanced at each other. In that moment, an understanding of men passed between them.

Mason stood, slipping the Journal into his jacket. "Right. I think I'm gonna need to do a bit more scrapping than I planned for this summer."

"Go get that punk, kid."

Known for their pale skin and bad attitude, these creatures are often mistaken for teenagers. Beware Gravity Falls' nefarious zombies!

Mason shut the Journal quietly, tucking it away. He'd followed Mabel and "Norman" out into the forest, growing more and more concerned the further they got from town. He was currently hiding behind a tree, not risking poking his head out in case the blue bill of his net-cap gave him away. He was relying entirely of his sense of hearing. If Mabel sounded even the least bit like she was uncomfortable, Mason was running out there and bashing Norman's head in.

The Journal made sense. The random bleeding, the limp, the difficulty doing things that required complex cognitive capabilities- it all added up! Mabel would probably make fun of him for being a conspiracy theorist, but Mason was fine with that. If it kept her safe, he'd do anything. Like stalk her when she's on a date!

He shunted that thought to the side, listening intently when Norman began speaking for longer than five words.

"Mabel… Now that we've gotten to know each other… Hoo. There's something I should tell you."

"Oh, Norman, you can tell me anything," Mabel fawned, acting like she was in a b-list movie. Mason nearly cringed.

"Alright, just, don't freak out, okay? Just keep an open mind- be cool!"

Mason heard the sound of a zipper being undone, and only the length of the noise kept him from dashing out. It went on for way too long to be the zipper to a pair of jeans. Norman must've been taking off his sweater.

"Is this weird? Is this too weird? Do you need to sit down?"

Mason chanced peeking around the tree, and almost shouted with shock. He managed to clamp a hand over his mouth, but immediately swung back around the tree. Standing in front of Mabel were five tiny men, stacked on top of each other.

Gnomes! Mason screamed in his head. How the heck did I mistake gnomes for a zombie!? Granted, I've never had experience with either of them, and I guess the horrible coordination could be chalked up to the gnomes acting as limbs being unable to really see, and that time Norman's hand fell off makes sense because it's just a prop, but what the hell!? And why the heck are a bunch of gnomes dressed up as a teenager and trying to date my sister!?

"Right, I'll explain," the gnome that voiced Norman said. "So, we're gnomes. Just, get that outta the way. I'm Jeff, and here we have Carson, Steve, Jason, and… I'm sorry, I always forget your name. Shmebulock…?"

"Shmebulock!"

"Yes, I got it! Anyways, us gnomes have been lookin' for a new queen! Right guys?"

The gnomes under Jeff began chanting Queen. It was really creepy.

"So, what do ya say? Will you join us, in holy matrignomey- I mean, matrimony?"

Mabel hissed. "Look, guys, I'm sorry. You're really sweet, but I'm a girl, and you're gnomes, and it's just like, What? Yikes…"

There was a long moment of awkward silence before Jeff began speaking again. "We understand. We'll never forget you, Mabel- because we're gonna kidnap you." And that was Mason's cue to jump in. He bolted out from his hiding spot, and crossed the distance between him and Mabel in moments. Just in time to catch the gnome he assumed was Jeff, who was flying through the air and about to latch onto Mabel's face. Mason grabbed Jeff by his copious facial hair and spiked him at the ground like a football, then placed a booted foot on the gnome. He turned to the other gnomes, who froze upon his arrival, and snarled at them.

"You little munchkins better turn around and head right back into that forest, or Jeff here's gonna become some fresh gnome jam." He applied more pressure to Jeff, who squeaked in fear.

"G-guys! Do what the crazy hugeling says! I don't wanna be jam!" he cried, grappling desperately with the massive leg.

"I love jam," Mabel whispered unhelpfully, hands squishing her cheeks in confused horror.

The gnomes scurried off into the forest, and Mason waited until he couldn't hear the snapping of twigs and rustling of grass, before taking his foot off Jeff. However, he quickly snatched the gnome up by his beard, and lifted him to look him in the eye.

"Listen here, Jeff. You the leader of the gnome colony or whatever in these woods?"

"Uh, y-yeah?"

"Alright, good. Then, spread the word to your little buddies- you ever come after my sister again, and I crush the skulls of every single one of you that I can get my hands on." Jeff nodded as much as he could with his tiny neck. Satisfied, Mason turned to Mabel. "Wanna do the honors?" he asked, making a kicking gesture with his leg. Mabel nodded excitedly. "Alright, on three. One, two, three!" He dropped Jeff, and Mabel punted the little man as hard as he could. The gnome disappeared into the forest, screaming in pain.

"That's for breaking my heart!" Mabel shouted after him, and then started giggling. She looked a bit too happy for someone whose heart was apparently broken. "Thanks for the help, Dipper."

"Anything for my little sister."

"Hey, I'm five minutes older!"

"Yeah, you're also five feet shorter," Mason teased, gesturing to the gap between the top of his head and hers. It was only about one foot, but her indignant pouting was too funny. Mason laughed boldly, the sound bouncing off the trees, and soon, Mabel joined him. They trailed off after a while, and started to walk back to the Mystery Shack. Mabel seemed a bit down, so Mason slung an arm over her shoulder, pulling her into a comforting side-hug.

"Hey, so you had one bad experience with a boyfriend- that doesn't mean you're gonna suck butt at relationships for the rest of your life. There's plenty of gnomes in the forest, May."

"Don't you mean there's plenty of fish in the sea?" Mabel asked, grinning up at him, braces on full display.

"Nah. It'll be, like, an inside joke. Something only we know- us two Mystery Twins."

"Mystery Twins?" Her eyes were sparkling at the new nickname.

"Yeah. There's a ton of crazy stuff out here in Gravity Falls, and I'm gonna need some help trying to get through it all. So; Mystery Twins?" he asked, holding up a fist. Mabel bumped her fist against his.

"Mystery Twins!"

I was working on my Danny Phantom fic, but it got a bit too depressing, so I started this on impulse. This is a mutation of the Fight Falls AU, where most everything stays the same, except Dipper and Mabel are hardcore fighters (although Dipper is the only doing any fighting). Dipper prefers going by his actual name, which is Mason, in this. Only Mabel calls him Dipper. The twins, and any other kids in the series, are fifteen. Obviously, Dipper's a lot taller and stronger, and overall cooler. Doesn't mean he's gonna be a musclehead- he's just gonna be a nerd that has a lot more to work with, so to speak. Don't expect things to pan out the same as in canon. Duh.