Author's Notes:

This is based on the Over the Garden Wall X Gravity Falls Hogwarts AU crossover by tumblr user imaginashon. If you haven't seen it yet, check it out! (It's been a few years since she's updated, though, so please don't bug her about it. I know she's been super busy!) She calls the story "Caerulus Ignus," which comes from the latin words for "cerulean fire," which doesn't sound ominous at all. Please note, also, that this is my second oneshot I've done for this AU. The first one is titled "Ambition." You don't need to read that one to understand this one, though. But. Um. I... uh... wouldn't complain if you did. *gives you a slightly sheepish smile and puppy dog eyes*

Anyway, this one takes place a little over a year since "Ambition" and a few weeks after a oneshot that imaginashon wrote about Wirt first meeting Dipper in person. You can find that story here (without the spaces): imaginashon . tumblr post / 129454310837/ It's hilarious, and I highly recommend you read it, but my own fic here should hopefully stand on its own. :) If there's anything you don't understand or that needs a bit of context, please let me know!

Wirt didn't hold a grudge against Dipper Pines for shadowing him all last year. Really, he didn't. He was a little bit annoyed by it, and a lot confused as to why the kid would even want to, but he didn't hold a grudge. He wasn't mad at him, either, for the way he'd talked to Greg that one time (even though, from what Wirt could tell, Dipper had been trying outright to manipulate Greg just so he could get closer to Wirt).

No, both of those things were, more or less, water under the bridge. So the kid looked up to him for some weird, unknowable reason. So the kid wanted Wirt to be his mentor. Alright. Wirt could understand that. …Or, well, maybe not understand, but he could maybe sympathize. It would be hard to have someone you looked up to turn you down like Wirt had done last month.

This, though… This was officially pushing things, and the plot to Dipper's little farce had started to wear thin.

"Do you have my schedule memorized?" Wirt demanded, whirling around to confront the tiny form crouched just behind a pine tree a little ways across the grounds. To Wirt's left, his friends Oliver and Pat snickered quietly.

"Oh! Sorry, man! I didn't see you over there!" Dipper called out, picking himself off the ground and brushing dried leaves off his robe. "I had a free period and was heading over to the lake to finish some homework outside for a change. Are you on your way to Herbology? Heh… Funny coincidence, am I right?"

Yeah. Coincidence. And Wirt was a talking horse.

"You were hiding behind a tree!" Wirt said, waving both hands in said tree's direction.

"I dropped my quill," Dipper said, and he held up the (supposedly) offending item up in one hand.

"It's, like, four degrees outside!"

"That's…" Scrunching up his brow, Dipper paused to tap the point of his quill to his chin. "That's what, like, forty degrees Fahrenheit? Forty-five?"

"Either way, it's way too cold to just randomly decide to study out here!"

"What can I say, man? The cold air helps he concentrate."

Suppressing a snarl, Wirt whirled back toward the greenhouses, pointedly ignoring Pat and Oliver, whose snickers were no longer as quiet as they had been a minute ago.

From the top of a nearby aspen, Wirt heard an amused twittering sound. His scowl deepened at the noise. He couldn't see Beatrice from where he was, but he shot the bluebird a glare regardless. He was positive it was her. She'd gotten irritated with him over something again that morning, and had apparently decided that she wanted to go pout and fly around the grounds for a while. For his part, Wirt couldn't even remember what she was mad about this time. Probably something ridiculous, as per usual. It would be just like her to sit there and make fun of him while he couldn't even do anything to retort.

Maybe he'd dump her in the owlery tonight, like he kept threatening to, instead of letting her into the common room like he normally did. It would serve her right for laughing at him.

"Hey, you gotta hand it to the guy," Pat said, giving Wirt a soft nudge in the side as the three boys continued walking toward their next class. "He's nothing if not determined!"

Wirt let out a long, exasperated sigh. "I think I preferred it when he was too shy to talk to me. At least then, I could pretend he wasn't spying on me every second of the day."

Herbology was, thank the heavens, uneventful. It wasn't Wirt's favorite subject, necessarily. He didn't exactly have a green thumb. …Or, well, that was an understatement. What was the opposite of a green thumb? Whatever it was, Wirt had it. He had a genuine talent for killing just about anything with leaves. It was ironic, really—literally hundreds of ingredients that were crucial for the potions he made came from these greenhouses. How he could be so good at mixing the things when they were dead, and yet be so horrible at handling them when they were still in the ground, was a mystery to him.

…And he didn't exactly relish the fact that the greenhouses were so close to the Forest, either.

Still, whatever issues he had with the class itself, at least Dipper couldn't actually follow him into the classroom, so that was a plus. Not to mention that Professor Longbottom was one of the nicest teachers there was, either inside or outside of Hogwarts. So for today, at least, it kind of evened out overall.

About three-fourths of the way through the lesson, when everyone was at work carefully (very, very carefully) fertilizing a collection of fanged geraniums, Wirt took a moment to catch his breath, wiping sweat off his brow. Rolling his shoulders to work out some of the stiffness from being bent over so long (and from, you know, tensing up with fear every time the geraniums swayed too close), Wirt glanced around the room at the other students. The Ravenclaws had this particular class together with the Gryffindors, and he could see a couple people he recognized from their Quidditch team scattered amongst the rows of plants.

As he looked around, a tiny patch of lighter, subtler green caught Wirt's eye, standing out against the violent yellow-green and red of the fanged flowers. He blinked, walked over to investigate, and then smiled a little when his suspicion proved to be right. He recognized those fragile, perfectly rounded leaves. A solatium sprout. The plant was as commonplace as a weed, growing anywhere and everywhere it could. He seemed to remember Professor Longbottom saying once that he could usually find at least one sprig of it growing anywhere in the greenhouses that the students visited on a regular basis. The seeds would stick to their robes, and then take root amongst the more exotic plants.

Crossing over to the little seedling, Wirt reached out gingerly and plucked it out by the roots, careful to avoid the geraniums as he did so. Then, he held the tiny leaves to his nose and took a sniff.

The aroma of dusty tomes and candle smoke, his mom's homemade blueberry pie, the stony scent of ornate, ancient cathedrals, and the fruity, sweet tang of Greg's favorite hard candies rose up to meet him. Wirt smiled, enjoying the scent, and took another deep breath of it before stowing the thing carefully in his pocket. When Wirt had first heard of solatium, he'd wondered briefly if it was used as an ingredient in amortentia, given the way it adopted the smell of whatever one found most soothing. But apparently the answer was no. In fact, it wasn't used much in potions, although it did have minor healing properties for burns and blisters.

A few months ago, Greg had come up to Wirt, proud of his discovery, and had announced that he'd found something in Herbology that might help Wirt with his… problem. Wirt had been irritated at the time, since Greg had nearly blurted out the sensitive information right in front of Dipper and his sister, but now, Wirt couldn't help but smile. The tiny plants were hardly Professor Orrick's potion, of course, which Wirt was careful to take like clockwork every day, but while they weren't exactly a cure, they did have a soothing effect. …And more than that, they reminded him of Greg's eagerness to help him, which always left him feeling warm.

"Hey, Earth to Wirt," Pat called from where he was wrist-deep in fertilizer a little ways up the aisle. "A little help?"

"Right, sorry!" Wirt stammered, and scrambled back to help. …And, in his haste, let one elbow get within biting range of one of the stupid flowers. Whoops.

"Oh, geez, that's got to smart," Pat said sympathetically, although the way he looked like he was holding back laughter kind of undermined the words. "You alright, mate?"

"Peachy," Wirt grumbled, examining his arm. Fortunately, the plants weren't poisonous, and it looked like this one hadn't managed to bite very deeply through Wirt's robes. With a sigh, he turned back to their work. Thankfully, there were only a few minutes left to go, and then they would be free to head off to lunch and relax.

Unfortunately, as Wirt realized a few minutes later, "relax" in his case actually meant "get stared at in a Very Obvious Manner" as Dipper tailed him through the halls when Wirt left to clean and bandage his elbow before eating.

…And then, it meant "get stared at in a Very Obvious Manner" from the Slytherin table across the Great Hall.

…And then, it meant "get stared at in a Very Obvious Manner" as Wirt walked over to the library to get a jump on his potions essay before his next class.

"You know," he announced loudly after five or so minutes of struggling futilely to concentrate while eager brown eyes watched him from behind a nearby bookcase. "I think I'm going to go study in the Ravenclaw Common Room instead. You know. That one room. Upstairs. For Ravenclaws. Where nobody from other houses is allowed."

"Oh my gosh, you spaz," a feminine voice whispered from where Beatrice was perched on his shoulder. On his way back across the grounds to the castle, she'd apparently decided that she'd be joining him again for the rest of the afternoon. "Did you want to try yelling a little louder? I think my other eardrum is still intact."

"Oh, shut up," Wirt whispered back, carful to not let his voice carry enough that the world's most annoying fanboy could hear him. "You're not even supposed to talk in front of anyone else."

"I know that!" Beatrice hissed. "Nobody's close enough to hear! And besides, do you have any idea how boring it is to only have you for a conversation partner?"

"You've got Greg, too," Wirt offered unhelpfully, and Beatrice let out a sigh. Instead of arguing the point, she turned her attention to the small brunette head that was bobbing along behind them through the corridors, always at a far enough distance that Dipper could claim that he wasn't aggressively spying on Wirt if he was cornered.

"You know, technically, non-Ravenclaws can get into the tower," Beatrice said, cocking her head to one side. "They'd just have to answer the riddle."

"Yeah, well even he hasn't been quite so obvious that he's actually tried getting into the common room," Wirt countered, hitching his bag up on his shoulder.

"Fair enough," Beatrice said with a shrug. "Just know that if you keep on ducking in there to hide, he's just going to find more creative ways to annoy you."

She was right, of course. That didn't mean Wirt had to like it.

Between hiding out in Ravenclaw Tower and the resume of classes, the rest of Wirt's afternoon was relatively Dipper-free. It was a pretty good afternoon, too. His last class for the day, Charms, was especially enjoyable. He allowed himself a small bit of pride at the fact that he'd ranked among the top five fastest people in his year to master the banishing charm, and even Beatrice admitted that she was impressed, though in her usual grudging and roundabout way.

Well, what she actually said was something along the lines of "Wow! I guess even a total dunce like you has to be good at something," but Wirt chose to interpret it as a compliment.

Normally on Thursdays, Wirt would have Quidditch practice after class, but today, it had been rescheduled for later due to a conflict scheduling the pitch. Apparently, one of the Hufflepuff beaters was in the hospital wing due to a badly misaimed curse, and their team was holding an emergency training session for their less-experienced replacement beater for their match against Gryffindor tomorrow. Instead, he headed over to the library, got some actual, quality work done on his homework with no distractions, and was feeling really pleased with the effectiveness of his day when he realized that he'd left his Standard Book of Spells back in the Charms classroom.

Beatrice teased him lightly on their way to pick it up, but things between them had settled back by now into their familiar, friendly rhythm. …Which, come to think of it, included about the same number of insults in both directions, but it was the feeling behind them that counted. He had just ducked inside the classroom, located his book, and was about to head back out when he heard the sound of a familiar voice in the corridor outside.

"Why didn't you tell me the Hufflepuffs were taking over the pitch today? It'll take me ages to track him down again!"

Dipper.

Wirt bit back a groan as Beatrice let out a muted laugh.

"It's not my job to help you spy on him," Mabel's voice retorted. To Wirt's dismay, the sound of footsteps paused as the two of them stopped to argue in the middle of the hallway. "Bro-bro, you've been at this for almost a year and a half, now!"

"So?" Dipper snapped back. His patience sounded nearly as worn as Wirt's was, at this point.

Agitated, Wirt drummed his fingers softly against the strap to his bag. There was no way to get out without opening the door and walking through right in front of the two of them.

"Oh, how the tables have turned," Beatrice whispered in his ear. "The spied-on has officially become the spy." Wirt did his best to shut her up with a sideways glare, but she just stared back at him smugly. She was, of course, technically right once again. It wasn't like he could stand here, listening for them to leave, without overhearing their conversation.

"…Sooooo, it's time to give it up, dodo-brain!" Mable exclaimed. "If he hasn't agreed to tutor you by now, he's never going to! Isn't it time for you to leave the poor guy alone?"

"You don't know that," Dipper said. "I think I'm wearing him down."

"What? As in you're annoying the guy enough that you think he'll finally…" she trailed off, and her voice rose in exasperation. "Wait—are you doing that on purpose? Is that seriously your master plan? To annoy Wirt into helping you?"

"No," Dipper said, defensively.

Yes, Wirt thought, bitterly.

"Ugh, Dipper," Mabel said, and there was the sound of a few quick footsteps and the rustle of cloth as Mabel closed the space between them. "Are you going cray-cray? Why—"

Then, there was an abrupt intake of breath from Dipper, and things outside the door fell immediately silent.

"Whoa, hey, are you okay, bro-bro?" Mabel said after a moment, sounding worried. "I didn't shake you that hard, did I?"

"It's nothing," Dipper said, but his voice had an odd sort of strain to it.

Despite himself, Wirt stiffened, a strange sense of unease starting to build in his stomach at Dipper's tone. He exchanged a quick glance with Beatrice. The bluebird's face was scrunched up a bit in confusion.

Then, there came the abrupt sound of shuffling and shifting cloth, and Dipper let out a yelp of protest. Then, Mabel gasped, and Dipper let out an irritated huff as the sound of footsteps indicated that one or the other of the twins had backed away again.

"Dipper…" Mabel cried in distress. "What happened to your arms?"

"It's nothing!" the boy insisted. "It's just a couple of bruises!"

"Dipper."

"Alright!" He let out another frustrated breath. "Some of the other guys were making fun of me, and they got a little carried away."

Wirt inhaled sharply, and he felt blood draining from his face in a mixture of shock and anger. He didn't like Dipper, necessarily—the kid had officially annoyed him half to death at this point, after all. Even so, that didn't mean the kid deserved to get bullied. On his shoulder, Beatrice was silent.

"How in the world is that 'nothing?'" Mabel demanded. "You got beat up!"

"It's not like it hasn't happened before," Dipper snapped, and his sister fell silent.

"Look, Mabes," Dipper continued, his voice equal parts angry, ashamed, and defiant. "This isn't anything new, alright? I mean, it's not usually so physical, but I'm used to this stuff by now. Why else do you think I'm so desperate to get Wirt to help me?"

Inside the Charms classroom, Wirt felt his stomach drop like a stone. His fists, he realized, were clenched in his robes at his sides, fidgeting restlessly.

"What do you mean it's nothing new?" Mabel said. "You don't… Do these guys beat you up a lot? Why haven't you told anyone yet?"

"No," Dipper said in exasperation. "I already said, it's not usually so physical. A lot of it's just name-calling. 'Mudblood,' 'screw-up,' things like that."

"And why haven't you told anyone?" Mabel demanded.

In response, Dipper let out a bitter laugh. "And do you really think that would stop them? I'm literally the only Muggle-born student in a house full of Slytherins, Mabel. And that's not even… that's not even counting how I'm just… me." There was a small beat of silence before Dipper continued. His voice had dropped until it was so quiet that Wirt had to strain to hear it. "I mean, people at our last school sure didn't seem to like me. Here, I'm just even more of a freak than I already was."

There was a longer pause, and Wirt shifted slightly so that his back was resting against the wall right next to the classroom door. Careful not to make any noise, he forced his hands to relinquish their hold on his robes, and folded his arms instead, hunching into himself as he continued to listen.

When Dipper finally spoke up again, his voice sounded exhausted and wrung out. He didn't even sound distressed anymore. He just sounded resigned. "It doesn't exactly help that I'm apparently so bad at magic. A lot of people keep saying I'm so close to being a squib that I shouldn't… you know. Be in Hogwarts at all. Between that and the Mudblood thing and… well, everything else, I didn't really stand a chance, you know?" Softly, he let out a sigh. "Look, can we just drop it, for now? It's almost time for dinner anyway."

"I still think you should tell someone," Mabel said in a mutter.

"I know," Dipper said, and there was the smallest hint of a smile back in his voice. "Look, can we talk about it later? I'm kind of… It's been a really long couple days."

Apparently, his sister relented, because after a moment, two sets of footsteps walked away from the classroom, heading in the direction of the stairs that would lead to the Great Hall. As the pair of them left, Wirt stood frozen for a few long seconds. Then, he steeled his nerves, pushed open the door, and headed in the same direction that Dipper had gone. He walked quickly to catch up to them, but then slowed and quieted his footsteps as he approached, staying carefully out of sight.

"Wait a minute," Beatrice hissed in his ear. "When I joked about you spying on them, I didn't mean for you to actually start following him around after this!"

Too late now. After tailing the pair silently through the halls for a couple minutes—long enough that he felt pretty sure they wouldn't realize he'd overheard their conversation, but before they'd reached any of the main areas for traffic on their way down into the Great Hall, Wirt broke off, darted through a quick shortcut that Greg had pointed out to him once, and came out in a corridor perpendicular to the one the twins were headed down.

He reached the intersection between their two hallways at almost the exact time they did. As soon as the twins came into sight, he paused and then let out a long groan while the two of them looked at him in surprise.

"Are you ever gonna stop following me?" he asked, studiously ignoring Beatrice's suspicious gaze. His heart was starting to pound a little in his chest. Distantly, he had the thought that, whatever other issues he'd faced because of his… condition, it had at least helped him develop a half-decent poker face.

It only took Dipper a second to smother his expression of delight at having coincidentally run into his hero. "Dunno what you're talking about!" he said, rocking back on his heels casually with his hands shoved into his pockets.

"For once," Mabel muttered to the side, apparently torn between exasperated amusement and her lingering sympathy from their conversation before. Less-than-subtly, Dipper elbowed her in the side.

Wirt pursed his lips, staring at Dipper for a long moment. He felt his gut squirming within him, and before he could second-guess his decision, he said, "One year."

Dipper blinked up at him in confusion. "Huh?"

"I said," Wirt muttered, grimacing, "One. Year. I will tutor you for the rest of this school year, and this year only, and when we're done, you will cut this out and leave me alone. Understood?"

There was the slightest beat after his pronouncement, during which all three of Wirt's companions stared at him in disbelief.

Then, Dipper's face lit up like a fireworks display.

"REALLY?!"

"Yes, really," Wirt grumbled. "You don't have to make a big deal out of—"

He was forced to cut off as Dipper let out a whoop punching both hands into the air. "Thank you! Thank you!"

"Hhhngh."

"You won't regret this, man! You'll see! Oh my gosh, thank you so much! See, Mabel? I told you I was wearing him down!"

Wirt's eye was twitching. Like, a lot. Was that normal? Were people's eyes supposed to twitch this much?

"I guess you did," Mabel said, letting out a giggle.

"It's not a big deal," Wirt huffed, watching Dipper continue to dance in place. "Look, I've got to get going. I… uh… I left my book in the Charms classroom. I guess I'll see you at dinner?"

"Yeah," Dipper said, breathless. "Yeah, of course! See you! Wow, great! That's… Wow!"

"See you, Wirt," Mabel chirped, and with a hand on her brother's shoulder, she gently steered him away, shooting Wirt a huge grin before they disappeared from view.

Fifteen seconds passed before either Wirt of Beatrice moved.

"Ooooohboy," Wirt breathed, running both hands through his hair.

"Well, you've certainly done it now, Beatrice said, fluttering to the floor and looking up at him skeptically. "I'd say you're in for a fairly interesting year, wouldn't you?"

Wirt let out an indistinguishable grumble, massaging his hands all over his face. Beatrice rolled her eyes, but then her expression softened, and she peered up at him intently.

"Wirt…" she said, and her voice was full of real concern. "Are you sure about this?"

"He's already been watching my every move," Wirt replied, lowering his hands with a full-body shrug. "If something happens, he'll probably notice it, anyway."

"Following you around from a distance, watching from behind pillars and bushes and whatnot, is very different from actually being up close and personal," Beatrice replied. "This guy's pretty annoying, sure, but he's also a whole lot smarter than he looks. Also, he's especially good when it comes to magical creatures. He's not even taking the official class for that yet, but I've already seen him walking around the school grounds a few times, looking at the Giant Squid and the Whomping Willow and writing everything down in some old book of his."

For a moment, Wirt froze. He hadn't realized the kid was good with creatures. "A-are... Um. Are you sure?"

"Of course I'm sure!" the bluebird insisted. "I've even seen him hanging around the edge of the Forbidden Forest! Honestly, it wouldn't surprise me if he's snuck in there before!"

At the mention of the forest, Wirt's body gave an involuntary shudder. "Well, it's too late to back out now," he said, a little less enthusiastically than he would have liked.

"No it's not," Beatrice scoffed. "You don't owe that kid anything. If you're feeling bad about the bullies, then feel free to tell a teacher or track them down yourself and give them detention or whatever. You're a prefect now, aren't you? What good is that fancy badge of yours if you're not gonna use it?"

For some reason, Beatrice's defiance only served to strengthen Wirt's resolve. "No," he said. "Or… Well, I mean yeah, obviously, if I can find out who those bullies are, they're definitely gonna be in trouble. But I already told him I'd tutor him for the year. I'm not backing down just because Dipper likes trees more than I do."

Beatrice looked at him for a moment, and then let out a long sigh. "I hope you know what you're doing."

"Yeah," Wirt agreed. "I hope so too." Reaching into his pocket, he drew out the little solatium sprout, which had started to shrivel without soil or water. He took a sniff. Parchment and new books, fresh rain and wood smoke, warm potatoes with sweet molasses. The soothing scents were as strong as ever. Holding it in one hand, however, Wirt realized he was trembling a little bit, and he couldn't get rid of the feeling that he may have just bitten off more than he could chew.

Author's notes/random factoids:

In this AU, both the twins and Wirt were born in America, but Wirt's family moved to London when he was ten, whereas Dipper has still only been in England for a little over a year. Hence the Fahrenheit/Celsius confusion.

I'm not sure if Neville would technically bethe Herbology professor at this point (the HP wiki said he became professor in 2017, and I think this AU takes place a few years before that), but hey, he's my second-favorite HP character, so have a little Professor Longbottom cameo.

The name for "solatium" comes from the Latin word for solace, comfort, and peace. And yeah, I made it up, more-or-less. Imaginashon mentions a soothing-smelling plant in her oneshot where Dipper talks to Wirt for the first time, and I thought "hey, why not?" The fanged geraniums, on the other hand, are 100% Harry Potter canon.