Mabel had taken it upon herself to head into town to buy some more knitting supplies, and despite the awful, stuffy air was enjoying the trip. The official town section of Gravity Falls was bustling with people doing one thing or another. Despite the decidedly not-sweater weather, she gave everyone – literally everyone – some sort of smile or wave or two-minute diatribe about how lovely their shoes or hair or pants or something looked. This drew her journey out quite a bit; by the time she'd actually gotten to the store and come out, her morning jaunt was becoming an afternoon one.

And she needed a break. Fortunately there were a few benches nearby, so she picked an empty one and plopped down on it to catch her breath. "Phew. It's hotter than a..." It was so hot her brain couldn't formulate an analogy. "...really hot thing. Wow. Nice job, me." She fanned herself with a hand and watched the people travel by.

Not all of them walked past, however. Someone tall and dressed even more warmly came to a halt and sat on the other end of the bench. It was impossible to tell much about them; the hood of their gray hoodie was up, and they had on baggy jeans that further concealed their form. This, of course, didn't stop Mabel from being friendly.

"Hi! Dude and/or dudette, you gotta be roasting," she greeted brightly.

Whoever it was didn't look over, but they did reply. "It's not too bad." Female voice. Very even and measured. Sort of gravely, too.

"Girrrrrrrrl please. I feel like some roasted French food I can't even say and I'm not wearing pants! What's the dealio? Why you in there?"

"I... feel a bit out of place, honestly."

"What?" That triggered a serious eye bulge. "Why for?"

"I'm..." Pregnant pause. "...new."

Mabel sucked in a gallon of air with her gasp. "Oh my gosh. Did you just move in?! You need a tour guide! I volunteer!"

Totally caught off guard, all the stranger could do now was look over and stammer "Wh-what?" Her face was somewhat visible, but detail was hard to make out.

"Seriously! You need a buddy? I gotcha back. My bro-bro and I know this town like the back of our hands."

"But I don't even know your name."

"Mabel!" She reached out a hand, expecting a shake, and after a few seconds got one. "Dang, you got some grip."

"So I've been told." The stranger turned away and looked down the street. "The air feels strange."

She also looked that way. "Oh yeah, it's the lake. Humidity and something or whatever. All I know is I have to use like a bottle of conditioner every night to stop the frizz from harshing my do."

The stranger's shoulders dipped a bit. "Your... right. Mabel? That's an interesting name."

She had to talk through a persistent giggle. "Yeah! I'm named after my great-great-great-great-great-great grandfather. Yeah. Grandfather. People had weird names back in the olden days. I think. That's what my Aunt Maud keeps sayin'."

Abruptly, the stranger perked up. "Maud? I know a Maud."

"Neato! See, we already got something in common." Mabel wasn't going to let the tenuous nature of the connection stop her. "So like, where ya from?"

There was some hesitance in her reply. "Oh, far away."

She tilted her head. "Like where? Iowa? Iowa is pretty far. And full of corn. So I hear, anyway."

"I... yes. Iowa."

"Huh. I always thought people from Iowa had weird accents." Her finger traced a happy path on her skirt. "I think I'm thinking of Wisconsin? Aw, I'm no good at geography. Dipper's the smart one. He's my bro. You got any bros?"

"No, but I have a sister." The stranger finally dropped her hood. She had a head of the blackest hair Mabel had ever seen, styled short and slicked against her head, with eyes of an equally intense blue. A frown came and went as she watched the passersby. "She's going to be coming soon, but I came first to make sure everything was ready."

"Ooo, no wonder you look mopey. I don't like it when I get separated from Dipper. Know exactly how you're feelin' up there." This was emphasized with a pat on the shoulder – which Mabel had to raise up somewhat to deliver. "Soooooo, what's your name?"

The stranger tilted her head. "My name is..." Again, she hesitated slightly. "Winnie."

Mabel's face went blank, though it still bore a smile. "The Pooh?" Silence. "Pff, I'm kiddin'. Nice to meet you!"

"Likewise." At last, she smiled too. "You remind me of a friend back home."

"Oh?" For a moment, Mabel fussed with her rainbow-colored sweater. "I've never heard that before. Dipstick always calls me 'hopelessly unique'."

"You could say the same about my friend." Winnie tilted her gaze up at the cloudy sky. "It is rather humid here, isn't it?"

"Heck yeah. How is your hair staying so flat? I'm super jelly." She squinted at the tall girl's slicked-down locks. "Hair gel?"

"Oh, yes. I like to keep it completely out of my eyes." A few moments quietly passed by before Mabel tugged at her sleeve. "Hmm?"

"Listen." A serious expression was on her face – not that it made her look any less cheerful. "You're gonna hear some weird stuff about this town. I'm talking gnome-level weirdness. If anything happens to you that you're just like 'nobody's gonna believe this', talk to me and my brother. We'll believe you."

Winnie's face dropped with confusion. "If you say so?"

"Seriously!" There was a bus approaching from down the street which Mabel pointed out. "That'll take you to a place called the Mystery Shack. If something dumb happens, just drop by." They watched it come to a halt at a bus stop. "Wait. I'm supposed to be on that. Frack! Hey! Wait!" She snatched her shopping bag off the sidewalk and started running. "Sorry gotta go nice to meet you again bye oh balls hey mister bus driver waaaaaait!"

"Hmm." Winnie blinked and watched her until she got on the bus. After it turned onto a side street and disappeared, she rose and patted at her hair. "I don't think the humidity is why the air feels strange," she muttered lowly.

Dipper found himself humming a little tune as he swept the shop. He was the only person in the building; Wendy hadn't arrived yet for some reason, and Stan and Soos were outside doing something to or around or near the bottomless pit. He really hadn't paid any attention to their conversation.

Just as he was about to get to the register, the door flew open with Mabel behind it. She let out a high-pitched "Dipper!" at maximum volume, which made him shriek, throw the broom, and fall over in a terrified heap. "Oh, there you are."

It took him some time to pull himself up. "M-Mabel! How did you know I was even in here?!"

"I didn't. I just like screaming stuff when I walk in to places sometimes. Make an entrance." She watched him adjust his vest. "Where's everybody at?"

"I have no idea where Wendy is. Grunkle Stan and Soos are outside doing... something. We probably don't want to know." After clearing his throat, he took the broom and went back to work. "Where have you been? It never takes you four hours to buy knitting supplies."

Giggling, Mabel held up her bag. "Bro, I had to meet a budget. Besides, I made a new friend!"

He hid his eyes and groaned. "Oh boy."

"Ah, relax. She's new here and I volunteered to be her guide." Except she hadn't done any guiding. At all. Her face screwed up. "Oops. I forgot to show her around. Oh well. I'm sure it'll be fine."

"Good job. I bet she's wandering around lost as we speak." Dipper cackled at her mean look. "What's her story?"

"I dunno, she's kinda shy. Her name is Winnie, she's from Iowa, she's got a sister, aaaaaand that's about all I got." Suddenly her eyes lit up. "Hey, you sound like her! All thoughtful and junk. I bet you'd be buddies."

"Huh. That's nice." The sweeping stopped. He delivered a pointed look. "Are you trying to set me up with her?"

She slammed her hands onto her hips and glared right back. "Whaaaaat? No! Come on, man, I met her like twenty minutes ago. Geez."

Dipper folded his arms. "You realize there is precedence for this sort of thing. Kindergarten. First grade. Et cetera."

His stern demeanor did nothing to diminish her grin. "I don't know what that big ol' p-word means. And it doesn't matter, 'cause no, I'm not setting you guys up. That would be a low blow to Wendy, man. A low blow." Now he was blushing. "Ha! Tomato face!"

"Why I oughta..." He feigned anger as she skipped away with her shopping bag and into the living room. She returned a few minutes later and hopped up onto the stool behind the counter. "I'm a little surprised you've only made three friends so far. Usually you're everybody's friend."

"I know, right? I blame the weird. And Gideon. Man." She propped her chin in her hands and sighed. "I'm so glad he's in the slammer."

"That makes about three thousand of us."

Before she could add anything, a series of noises from outside drew their attention. "What was that?"

Dipper listened for a moment. "I don't hear anyone screaming. Probably fine."

She nodded. "Yep. I don't wanna go out there, yo. Soooo hot."

"Yeah. Honestly, I didn't think it could get this hot in Oregon. We're almost next to Canada!" They shared a laugh. Just as he went back to sweeping, Wendy opened the door. "There you are. Sleep in?"

"I wish," she groaned, pawing at her furry hat. The redhead was bleary-eyed and sluggish. "I've been up since six o'clock 'cause my dad was... man, I don't even wanna talk about it."

"No, no, tell us!" Mabel encouraged. "We love stories. Dipper especially seems to love ones with you in them."

He chuckled nervously. "Yeah sure ahem... what happened?"

Wendy took the stool and got comfortable. "Dad gets his hacksaw stuck in a Douglas fir. So he punches the tree, right? Well, the tree falls across the highway so my brothers and I gotta help him clear it. Except he gets the saw stuck again so he hauls off and slugs another tree and that one falls in the road too. I gotta get him to take some anger management classes." She smiled and rolled her eyes as the twins giggled. "So, there you go. I spent five hours makin' sure the highway was tree-free."

"Poor Wendy," Mabel said, though she was still grinning. "The life of a lumberjack!"

She nodded and brushed some hair out of her face. "Yep. I miss anything around here besides Mr. Pines building a trampoline over that hole in the ground?"

"Is that what he's doing?" Dipper looked out a nearby window. "I swear, sometimes he's trying to get sued."

"Maybe he's just in the part of his old man-dom where he's starting to hate everybody." A beat passed before Mabel's eyes lit up. "Ooo! I made a new friend!" She waved her hands around. "Her name's Winnie. She just moved here."

The redhead thought for a second. "Oh yeah, that must be the chick that moved into Pacifica's neighborhood. She hasn't been here long enough for gossip to start though, heh."

Dipper blinked as his sister's face got droopy. "What's up?"

"Aw man, all the rich people in Gravity Falls are total jerkfaces." She crossed her arms and got dramatically pouty. "Pacifica's a jerkface, Gideon was a turbo jerkface... and his dad is just... ew." But in a moment more her smile returned. "Then again, Winnie didn't seem like a jerkface at all. Maybe the third time's a charm."

Her brother added with a smirk, "Yeah, if the town doesn't drive her insane first."

"That would never happen." Wendy cackled for just a moment before her face dropped. "Unless she runs into ghosts too. Man. Ghosts."

"Not to worry! I told her to drop by if she had any issues." Mabel titled her head at Dipper's surprised look. "What?"

"This place is insanity central. All she'd get is Stan harassing her to buy a keychain or a bobblehead. Or she'll end up on a tour. That's really going to give her a good impression."

"Why wouldn't it? We got a Sascrotch! Hee." She frowned when neither of them cracked a smile. "Y'all so dreary today. Here, look at my sweater. Absorb its happiness!"

Dipper declined, covering his face with the brim of his hat. "I can't, it makes my eyes burn."

"Uh... same, actually," Wendy added, glancing about to avoid the rainbow brilliance of Mabel's outfit. "You are extra colorful today."

Mabel folded her arms again, this time with a huff. "Geez. You beam one rainbow into someone's eyes and all of a sudden colors are bad."

Dipper peered at her. "You blinded that someone for four days and he still says his brain is yellow."

"So what? Color needed to happen and color happened. I stand by my actions." Before an argument could get going, a loud bang and shouting from outside made everyone look toward the door. "Uh oh. I think Soos did a Soos thing."

"Yep." Dipper set the broom aside with a sigh. "I guess we'd better go see what's up."

Winnie found herself in the small electronics store downtown, eying some of the smartphones on sale. As she walked between displays, she slipped her hands into the pockets of her hoodie. One phone caught her attention – black and gleaming with a huge screen, it stood out amongst the smaller examples like the biggest jewel in a technological crown. She blinked at it. Unfortunately, there was a rather large number on the price tag. "Oh dear." Seeing no way around it, she checked her surroundings, frowned, and walked out. On the sidewalk, she exposed her left hand and looked at a phone which was now in her grasp – the phone she'd been looking at before. "I guess it worked." After waiting a bit to see if anyone had suspicions, she headed down the sidewalk and towards the hill where the who's who of Gravity Falls made their homes.

It was something of a climb, but no problem for Winnie. About twenty minutes of walking brought her to what could only be described as the most modest out of a small clump of mansions. This was a single-floor structure clad in brick with a slate shingle roof and wide windows out front. The lawn was carefully manicured, as were all the lawns on this street. She only cracked a smile when glancing at the rose bushes that bracketed the front porch. After sucking in another breath of muggy air, she entered.

The interior was completely empty. Every step on the hardwood caused a scuffing noise from her sandals that bounced for ages through the house. "This is too much," she grumbled to herself. "If I'd had a choice..."

Knocking quieted her. She looked through the semi-circular window in the front door and saw a familiar face – her own. It opened after the caller noticed she had been seen. "Sister!" she said, darting over and clamping onto Winnie in a hug.

"That is very bright," she noted, cocking a brow at the red dress.

"What? It's my favorite color." Her eyes were the same shade. "...Winnie. Ha."

The tone made her squint. "Sue. I feel like I'm on a leash again."

Sue patted at her bangs and issued a light shrug. "But at least you have company."

"Hmm. Yes." Winnie shed her hoodie and pulled at the straps on the black tank top underneath it. Besides their eyes and hair style, the twins were identical in every way – including their builds. Somewhat broad-shouldered and very athletic, they struck imposing figures. "We should get to work. Did you smell the air?"

"Yes." Sue crossed her arms in thought. "It's like breathing flesh." She cut her eyes up. "Don't we need furniture first? If people want to come over..."

Her idea was dismissed with a frown. "Nobody wants to come here. The neighborhood is too intimidating." Ah, but that might not be true, she realized. "Hmm. Unless the girl I met shows up."

Smiling, Sue took her by the hands. "Oh? Did you make a friend?"

Winnie nodded a little. "Perhaps. Her name is Mabel. She felt it important enough to warn me about the 'weirdness' of Gravity Falls."

"Huh. I guess there's a reason that the air is so..." There wasn't a fully accurate word for the sensation, and so she fell silent for a time. "We're still going to need furniture."

"You certainly enjoy decorating, don't you?"

She clasped her hands and grinned widely. "It's a hobby, and I rather like it. You could use one." They smiled at each other before she added, "What is that rhyme about all work and no play?"

"As if either of us have to work for anything." Winnie detached herself and stepped away. "Although what's happening here could be... a challenge."

"Between your pragmatism and my social skills, I'm sure we'll manage." They shared an amused look. "And all the other things which are ours."

For a while, they were quiet, walking through the house to get their bearings. Sue looked over to one of the empty walls; except it wasn't empty now. A large painting of a stream running through a forest was hanging there. "First, some art. How does this look?"

"Nice enough." Winnie stood by her and examined the frame. "We have to play this carefully, you know." Her eyes narrowed when Sue didn't respond. "I'm serious. We could break things here. Lots of things. The people here... they are not ready for us."

She heaved a dreary sigh and looked over. "Oh, sister. You don't have to tell me that. Nobody is ready for us."

By the next morning, Winnie and Sue had a completely furnished home. Nothing was too ostentatious about the decor, but everything matched the general majesty of the house. Sue was on the front porch with a mug in her hand, watching the sun rise over Gravity Falls. It wasn't long before her sister joined her. "Nice view," she greeted, indicating the vista with her mug. "Not too far away from some of the places back home."

"Yes. Trees everywhere." Winnie glanced at her cup. "Coffee?"

"No, just water." She took a swig. "Where do we even start? We know nothing about this place."

"I know someone who does."

Sue's head titled in confusion briefly. "Oh, yes. Your new friend." Winnie didn't add anything else. "Are we taking a trip already?"

"As soon as the sun is a little higher. There's a bus we need to catch and I imagine it's a little early for that."

"Exciting. I haven't gotten to see anything yet." Sue drained her cup and dried off her lips. "Mabel, right? What's she like?"

"Young. Very..." Winnie rolled her eyes about in search of a good term. "Energetic. Fast talker."

"Sounds familiar." They shared a smirk. "Where are we going?"

"A place called the Mystery Shack. All I know is the name."

To kill time, they walked down the hill and into Gravity Falls to watch the town wake up and get an idea of where everything was. The sights included the floating winged dollar sign over the Gleeful car dealership – something that Sue couldn't stop giggling at – as well as the graffiti on the water tower, the lake, and all the little shops downtown that Winnie pointed out for her sister. By the time the sun was fully up, they ended their tour at the bus stop Mabel had run to the day before. They sat on the bench and waited.

"It's cute," Sue decided. "Not much different from home, really." Her lips pursed at a thought. "Besides the sky being so empty."

"Yes." Winnie crossed her legs and stared at the clouds. As time passed, a little crowd gathered around them, apparently all waiting for the same bus. "Hmm. Popular place."

She nodded a little and examined the gathering. "I noticed."

The bus arrived about ten minutes later. Everyone piled on. The twins chose a seat near the back and remained silent during the trip into the woods. Once they actually saw the Mystery Shack, however, Sue couldn't help but speak. "This... isn't what I was expecting," she muttered.

"Same." Winnie's eyes were narrowed. "The air is even worse here."

Only after the rest of the group got out did they emerge. Sue blinked at the fallen 'S' on the grass, while Winnie was more interested in the totem pole off to the side near the trees. The rather dilapidated nature of the building made both women scowl. "Are you sure someone lives here? This looks like a museum. A bad museum," Sue asked.

"This is where she said to go..."

Quiet arrived as someone came out of the house. "Ladies and gentlemen!" he proclaimed, steadying the red fez on his head. "Welcome to the Mystery Shack! You can call me Mister Mystery, or Stan... actually to be honest you could call me Shirley if you were gonna make it worth my while..." The last part of that was mumbled and fast, but the twins still heard it. "Anyway, if you'll follow me right through this door we can get the tour started!"

The group began to move after him, but the twins had no intention of going along. After feigning compliance until the group was gone, Winnie sniffed the air. "Overpowering. We need to find what's doing this."

Sue tugged at her red sandal wedges and looked for things to investigate. "Right. Should we split up?"

"No, let's stick together." They moved toward the side of the house with the totem. "What's this?"

"Looks like a big wooden stick." Sue tapped on it with a fingernail. "...now I have a splinter." Grumbling, she yanked it out from under her nail. "Hmph."

Winnie shook her head at the display and looked off. "I see a hole in the ground." Upon getting there, they found scattered metal tubes and a wooden sign. "Bottomless pit?" She peered down into the abyss. Almost immediately, an overpowering sensation struck. "That is definitely a thing."

"It sure is," her sister agreed, waving away the air out of instinct even though the sensation wasn't really a smell. "Should we jump down?"

"Uh, excuse me?" an uncertain voice interrupted. They turned to see a young boy in a hat and blue vest and grayish shorts, amongst other things. "Are you here with the tour? They kinda went that way." He thumbed over his shoulder.

Winnie approached him first. "Actually, we're looking for Mabel. My name is Winnie."

"Oh, so you're the new... arrivals. Plural." He tilted his head at Sue. "Identical twins, huh? She is gonna blow a freakin' gasket."

The red-eyed woman was curious. "Why?"

"Because-"

He didn't get a chance to finish since Mabel burst out of the side door behind him. "Diiiiiiiiiiipper! What the frackety fricky frack did you do with my hairband, man?! I put it on the... table...?" Her voice failed completely upon seeing Winnie, only to return as a thrilled, gurgling shriek when she noticed Sue. "Oh. My. Gosh. You guys are twins too! Natural clones, even!"

"Here it comes," Dipper sighed, not even trying to stop her as she darted off the porch.

"Eeeeeeee this is awesome!" she shrieked, running quick circles around the two women. "Why didn't you tell me you were twins?! We coulda had a huge twin party!"

"Wow, she is energetic," Sue said with a tiny grin.

"Mm. We just thought we'd stop by and say hello." Winnie gently stopped her with boths hands the next time she ran by. "Don't get dizzy."

"Pff, dizzy? I'd never get di-dizzy." The hitch in her voice – and some random eye wobbling – said otherwise. "Okay, uh, the sky needs to stop being the ground. That's not cool."

"Oh boy." Dipper guided her away as she started to retch. "She'll be fine. Welcome to the Mystery Shack! Believe it or not, we live here. I think we might be the only people Grunkle Stan doesn't try to charge an entry fee."

Sue blinked. "What's a Grunkle?"

"Grunkle's a portly manatee of Great and Uncle!" Mable explained, her cheeks bulging as the last words got out. "Oh snap, I'm gonna hurl..."

Were he not busy trying to stop her from doing just that, Dipper would have facepalmed hard. "She means portmanteau. Sorry. She ate half a bag of Cookie Chips for breakfast and I am genuinely concerned her heart is going to implode."

"Sugaaaaaaaaaaaaaaaaar," she droned in confirmation.

While they fussed with each other, the identical twins shared a dark expression. "Well, I wasn't expecting this," Winnie muttered, trying to avoid attention. The sting of the feeling that flowed from the bottomless pit still rattled around in their skulls.

The red-eyed twin nodded, then stared at a goat that appeared from around the back of the house. "I don't know what I was expecting, but I can't disagree with you."