Author's Note:This fic was written for the Hogwarts AU that came from imaginashon on Tumblr. It's a Gravity Falls X Over the Garden Wall crossover, and it's BEAUTIFUL! It's been a while since it's been updated, but please don't bug the author about it—she's been crazy busy over the last few years and just hasn't had the time to get back to it. The story involves Dipper, Mabel, Wirt, and Greg each becoming Hogwarts students (of course), and will eventually involve both Bill and The Beast as antagonists. Wirt has a way with magic, especially potions. For Mabel, magic comes easy! Dipper, though… Dipper struggles with even the most basic of spells. It's humiliating.

In the AU, imaginashon has Mabel in Griffindor and Dipper in Slytherin. (They have a sort of "twin telepathy" thing going on, which allows them to keep in contact despite being in different houses). A lot of people have been confused by this choice, especially since Alex Hirsch once tweeted that Mabel would be a Hufflepuff and Dipper would be Ravenclaw. I'll admit that I was a little confused at first, too, but then I read a little bit more, and… IT FITS. It fits so well. Frankly, I LOVE it, especially in regards to Dipper.

Just… think about it. Dipper is intellectual, yes. ("If I'm not the smart guy, then who am I?") But this is also the guy who has his entire future planned out at age twelve. Who was so dogged in his pursuit of the girl he liked that he made a hundred-step plan and then cloned himself, like, fifteen times to accomplish it. Who became so obsessed with the mystery of the Journal that he was willing to sacrifice sleep, sanity, and safety to solve it. There are many traits, both positive and negative, that Dipper has that fit in perfectly with the Slytherin manifesto. So yeah, Dipper may fit in Ravenclaw… but he's going to make one heck of a Slytherin.

"Pines, Mabel!" Headmistress McGonagall's voice rang loud and clear through the Great Hall, echoing slightly in the enormous space. Dipper, along with the rest of the first years lined up at the front of the hall, looked around at Mabel as she stepped forward towards the bedraggled wizard's hat laid on the stool in front of them.

"Good luck," he whispered to his sister as she left his side. Mabel threw a big, braces-filled smile in his direction in response.

Of course, Dipper thought as he watched her go, it's not like she really needs luck. Mabel was... well, Mabel. He was sure that no matter what house they put her in, she'd excel, leaving her usual piles of rainbow-colored glitter in her wake. She'd always had a way of making friends and turning any situation into a good one, no matter where she was.

Despite the uncomfortable squirming that filled his stomach when he realized how close he was to his own sorting, Dipper couldn't help but chuckle under his breath as Mabel plopped herself onto the stool and practically jammed the old wizard's cap on her head. As the hall waited for the Sorting Hat to make its pronouncement, Mabel's legs pumped back and forth in giddy excitement. She looked like a kid on Christmas morning, just about to unwrap the biggest present in her pile.

Dipper was still smiling a bit when a very familiar voice broke into his own line of thoughts—Mabel, sending him one of her own, overly excited telepathic messages through the weird psychic-twin-connection-thing they'd had since they'd been born.

[Ohmygosh,] she said, squealing in his head. [Dipper, this is so cool!]

[Mabel!] Dipper shot back in response, burying his face in his hands. [Seriously? Not while you're being sorted! What if… I dunno, it messes with the way the spell on the hat works, or something?]

[Party pooper,] Mabel said, but then fell silent as they continued to wait.

It was barely ten seconds later before the hat jerked into motion as it had with each of the previous first years, the hole along its brim opening wide to bellow "GRYFFINDOR!" to the waiting crowd.

The table on the far left side of the room erupted into noise, with many a grin and the occasional rowdy whoop ringing through the air. Removing the hat and placing it back on the stool, Mabel shot Dipper a final, elated look as she went down to join the other members of her new house.

Dipper softly joined in with the applause to support his twin, but once the cheering died, he felt the butterflies in his stomach return. He knew he would be next, and he fixed his eyes on the headmistress as she raised the scroll to read the next name.

"Pines, M—…"

"Dipper!" Dipper called out, interrupting reflexively before he'd really thought things through.

Headmistress McGonagall looked sharply in his direction. There were more than a few raised eyebrows being sent his way from students and teachers alike. A bit uncomfortably, Dipper cleared his throat. "Um… call me Dipper. Please."

Headmistress McGonagall pursed her lips. "Well, Dipper Pines, I'm glad that you've seen it fit to tell us that there was an error in our registers. We couldn't have a student's name listed incorrectly on the Hogwarts school records, now could we?" Her dry, sarcastic statement was met with a smattering of laughter from the students.

With scarlet cheeks, Dipper muttered, "Yes, ma'am," and advanced toward the stool and the worn, pointed hat placed atop it. It figured. He'd hardly spent ten minutes at his new school and he had already embarrassed himself. That had to be some kind of a record. Still, Dipper wasn't about to spend the next seven years of his life having people laugh at his humiliating first name, either. Taking the hat carefully by the brim, Dipper slid onto the stool and placed it over his head.

"My, if it isn't the other half of the Pines duo," a small voice murmured in his ear, and Dipper nearly jumped out of his skin.

"Interesting," the voice said. "It's been a year or two since I've seen someone with such strongly diverse qualities. Oh, yes, there are several good houses that would be very fitting for you. The question, though, is which one fits you best."

[Well, Dipper?] came Mabel's voice into Dipper's head. The hat fell silent, as if it had been interrupted, and Dipper knew without asking that it had been able to hear her clearly. [Isn't it cool? I can't wait to tell Mom about the talking hat! So how's it going? What's he saying? Does he know where to put you yet?]

[Mabel, are you kidding me?] Dipper shot back at her hastily. [Not now!]

The hat chuckled a little, and then said, "Ah, yes. I certainly made the right choice with that one."

Dipper grimaced, but relaxed a little at the hat's amused tone. Again, it chuckled, and then continued on with a more contemplative air. "The two of you are very different, mind you. Different qualities, different motivations, different skills."

Internally, Dipper nodded, but he couldn't help the way his heart sank at the words. When he and Mabel had first gotten their Hogwarts letters, of course, he'd had no idea how the house system worked. Heck, he hadn't known there were houses, period. Everything about this was new and strange and exciting, and even after their great-uncles had explained a little about the wizarding world, there were a lot of things that they were learning as they went. Listening to the hat's song a few minutes ago and realizing for the first time that people were separated based on their personality traits… well, it had come as a pretty unpleasant surprise. He and Mabel had done pretty much everything together over the last summer at Gravity Falls, and since they were the same age, they'd been in a lot of the same classes at school over the years. The thought of being sorted into two separate houses with different schedules, different dormitories, and even different tables for meals just felt… odd.

Well, it wasn't like there was a ton he could do about it. The way the two of them worked, after all, they often seemed like perfect opposites of one another. Mabel was led entirely by her heart, whereas he relied on his mind. She liked rainbows and pigs and all things glittery. Dipper was more drawn to mystery novels, geeky video games, and the ideas of adventure and mystery. She was a die-hard optimist. Dipper? Not so much.

"Yes, very different indeed," the hat said, as if it was agreeing with him. "…Although there are also similarities, to be sure. You, too, are certainly brave, Dipper Pines. Oh, yes, I will give you that—in much the same way that a young Gryffindor named Neville Longbottom was, not all that many years ago. You have a warrior inside you, just waiting to bloom. …But you have other qualities, too—and ones that stand out more sharply than those most prized by Gryffindor."

Dipper blinked. He was, admittedly, a little surprised at the Sorting Hat's first few statements—though he was usually the last person to admit it, he wasn't exactly known for being the bravest type. He'd spent a lot of time at his last school dodging his classmates' (often-successful) attempts to spook or startle him—and then ignoring their laughter and the whispered insults of "Scaredy Cat," "Wimp," and "Baby" that always hounded him when the teachers weren't around.

Really, I guess the choice is pretty obvious, huh? Dipper questioned, though he was a bit unsure of whether the Sorting Hat could actually hear his thoughts. Apparently, he wasn't a Gryffindor, and he already knew that he wasn't going to be in Hufflepuff—he held too many grudges for that. No, Dipper's place would lie with his passions for reading and exploring and discovering new things. Going by the hat's descriptions from its song not long ago, Ravenclaw was the obvious choice.

"Don't be so sure of that, my boy," the hat whispered, once again sounding amused. Dipper's eyebrows shot upwards. Apparently, the hat could very much hear his thoughts, and not just the ones that Dipper actively directed at it. Nervously, Dipper ran his tongue along the inside of his teeth. He wasn't really sure how to feel about that.

"You are clever, don't get me wrong," the hat said. "And you certainly do think of yourself as intellectual, don't you?"

Well of course, Dipper thought with a frown. What else would I be?

…But even before the hat answered, a handful of memories swam to the front of his mind, and a feeling of realization settled in his chest as he sorted through the images. There was himself, age seven, resolutely working on every project he was handed with twice the vigor of his classmates, determined to prove to them that he was more than just a wimp to be bullied. Himself, age eight, declaring to his parents for the first time that he was going to have his own ghost-hunting show—a dream that Dipper hadn't budged on even as he'd grown older over the past few years. Himself, age eleven, enrolling in all of the honors classes available to him in Muggle middle school, unaware at that point that he would be going to Hogwarts. …And if he was being perfectly honest with himself, he knew that deep down, it wasn't really just a genuine thirst for knowledge that had motivated him. He had done it with the desire to rise above everyone else, to prove that there was something he could excel at, to show his tormentors that they were wrong, to complete Middle and High School with so many flying colors that he would make even Mabel's rainbow sweaters look like they'd been knitted in black and white.

"Ah," the Sorting Hat said with a smile in its voice. "You can see it, can't you? The traits that motivate you most are a desire for recognition, unrivaled stubbornness, the ability to dream big and stick to those goals in spite of the obstacles in your path. In short, ambition. The decision is close, yes, but in the end, I think it had better be SLYTHERIN!"

There was a ringing silence following the Hat's shouted pronouncement of Dipper's new house. Stunned, Dipper plucked the hat off his head, rose, and set the thing gingerly back on the stool. He wasn't the only one who seemed surprised at the hat's decision—people from every table were staring at him openly, and the buzz of whispered conversation filled the air.

There was no applause from the Slytherin table.

Uncertainly, Dipper glanced back at McGonagall, who nodded toward the mass of students whose green and sliver neckties, shirts, and sweaters stood out starkly against the black of their Hogwarts robes. Feeling numb, Dipper walked forward, and at the motion, a small handful of Slytherins started clapping belatedly—mostly prefects and a handful of older students who were looking pointedly at the others around them. Reluctantly, the rest of the table joined in.

When Dipper reached them, he found that the seats nearest him had suddenly become occupied by textbooks, bookbags, cloaks, or even people's feet where they had propped them up. Uncertainly, Dipper made eye contact with a girl who looked about his age. She had her purse out on the seat next to her.

"I'm saving this place for someone else," she said, cold grey eyes glittering in her face. "Why don't you go find another one?"

Behind Dipper, at the front of the hall, the next first-year stepped forward to take the Sorting Hat. Dipper felt his face flush a dark shade of pink as he began walking along the table, trying to find an empty spot. "Are you kidding me?" he heard someone whisper as he went along. "That Mudblood is actually in our house? Has that ever happened before?"

Finally, about halfway down the table, a prefect with deep brown hair met his eyes. There were already people in the seats on either side of him, but when it became apparent that the students nearby with empty spots next to them weren't going to let Dipper in, he gave an exasperated sigh. "Oh, come off it," he muttered angrily at his surrounding housemates. "It's stunts like this that make everyone else hate us so much, you idiots. Come on, Dipper," he said, standing up. "You can have my spot."

Dipper nodded gratefully and quickly sat down in the empty seat. The prefect turned away and settled down in another place somewhere to their right, grumbling under his breath.

Looking up and down the table, Dipper caught sight of a few more sympathetic faces. A girl with curly blonde hair gave him a cheerful smile, and a couple of people grimaced and sent him a helpless shrug. The vast majority, however, were either steadily avoiding eye contact or were shooting death glares his way.

[You okay, bro-bro?] Mabel asked in his mind, a little hesitantly.

[I'm fine,] Dipper snapped back, coming off a little harsher than he'd meant to. [Why wouldn't I be?] A burning heat was rising in his chest, and he found himself balling his hands into fists on his lap.

I'll show them, Dipper thought as he clapped politely for the next student down the line, who was also sorted into Slytherin. I'll show them all. Muggle-born or no, I'll prove that I belong here—I'll learn so fast and get so far that I'll knock the smug, stupid grins off every single one of their faces.

If only Dipper had known then just how difficult fulfilling that particular ambition was going to be.

UPDATE/A NOTE FROM THE AUTHOR:

You guys. Seriously. You guys are AWESOME.

I swore I wasn't gonna come back to this story. I told myself it was JUST going to be a oneshot, because I know that I can have commitment issues with finishing things… but for some reason, you people kept favoriting, and following, and reviewing this fic, and it made me get inspired, dang it! So here, you crazies who actually like my story for some reason—I've posted another oneshot under the name of "Second Shadow," which is from Wirt's pov and takes place about a year after the first one. …And there'll be more on the way, pretty soon! *throws several thousand more words at you haphazardly*

Rather than being one big multi-chapter story, I've planned for this to be a series of interconnected oneshots. If you use Archive of Our Own, I'm also posting them over there in a series entitled "Shadows of the Mind."

Seriously, thank you guys so much for the encouragement. I hope you like the rest! ^-^