Author's Note:
Disclaimer: This is a work of fanfiction based on the Harry Potter Universe. All the recognizable characters, the plot and settings are the property of J. K. Rowling. I claim no ownership.
The setting is in an alternate universe. My main focus would be to write multi-dimensional and relatable characters in a realistic setting. Currently it's rated M just to be safe, I might change the rating in the future accordingly. Story is cross posted on Fanfiction, Archive of Our own, Royal Road and Webnovel.
Once again sorry guys for the late update. I have been sick since the last week. I'll be uploading an extra chapter this week as I uploaded only two chapters last week.
Also I am editing and revamping parts of the story from the feedback I got in reviews. Mainly they would be some mistakes I made and somethings I wanted to add that I forgot. The basic story would remain the same.
Chapter 13 - Magical Mathematics
The Dursley household was alive with excitement on Saturday morning. The tantalizing aroma of bacon and eggs wafted through the house as Petunia prepared breakfast, and the chatter of voices filled the rooms. The plan was set—another visit to Diagon Alley. Everyone, including Aunt Maggie, was in high spirits. She had been there during their first trip, and while skeptical at first, she had left thoroughly fascinated by the magical world. Now, she was just as eager as the others to dive back in.
"Vernon, do hurry up with that checklist," Petunia called from the kitchen, expertly flipping pancakes. "We don't want to forget anything!"
"Checklist is done, love," Vernon replied, marching into the kitchen with a clipboard in hand. He was wearing his favorite weekend shirt, a light blue button-up that Dudley always teased made him look like a science teacher. "Car's ready, bags are packed, and Maggie has already triple-checked Ripper's crate."
Maggie, slurping a chocolate shake at the table, raised an eyebrow. "Triple-checked because someone didn't lock it properly last time. You almost had a bulldog loose in a magical market!"
Dudley snorted as he stuffed a piece of toast in his mouth. "I'd pay to see that. Can you imagine Ripper chasing a cat that could probably breathe fire?"
Harry, sitting beside him, grinned. "Or getting into a shouting match with a parrot that recites spells."
Maggie chuckled, shaking her head. "Laugh all you want, boys. That dog's got more sense than some of those wizards we saw."
Vernon clapped his hands. "All right, enough dawdling. Let's get going before the shops get crowded!"
The family piled into Vernon's spacious Suburban, their excitement palpable. Harry and Dudley claimed the back seat, with Harry taking the middle so Ripper could sit by the window in his crate. Petunia and Maggie sat up front, chatting about their last visit.
"So, Maggie," Petunia began as they merged onto the main road, "have you recovered from seeing a self-stirring cauldron? You seemed quite taken with it last time."
"Taken?" Maggie scoffed, though her eyes twinkled with amusement. "I was thinking of buying one for my kitchen. Imagine not having to stir my stew for hours on end!"
Dudley leaned forward. "What about the quills that write on their own? You were eyeing those pretty closely, too."
Maggie shrugged, trying to appear indifferent. "Well, I won't lie. They're clever inventions, those magical folks. But let's not get carried away." She paused, then added with a wry smile, "Although I wouldn't mind one of those shrinking trunks for my fieldwork. Packing gear would be a dream."
Vernon chuckled from the driver's seat. "You're starting to sound like a convert, Maggie. Next thing we know, you'll be brewing potions."
"Only if they involve brandy," Maggie shot back, making everyone laugh.
Harry, looking out the window, grinned. The lively banter filled the car, making the journey feel shorter than it was. He loved these moments with his family—a blend of humor, warmth, and the occasional jab that always landed with affection.
When they stepped through the enchanted brick wall into Diagon Alley, Maggie was just as wide-eyed as she had been during their first visit.
"Still gets me every time," she admitted, her voice tinged with awe. The vibrant street buzzed with life, wizards and witches bustling about, carrying packages, haggling with shopkeepers, and chatting animatedly.
Harry noticed Dudley trying not to look too impressed. "Come on, Dud, just admit it. It's amazing."
Dudley shrugged, his lips twitching into a grin. "It's all right. I mean, the guy selling broomsticks over there is kind of cool."
Maggie pointed toward a witch carrying an armful of cauldrons. "How's she not dropping those?"
"Probably a charm," Harry said, leading the way to Eeylops Owl Emporium. "Speaking of amazing, wait till you see this shop."
The familiar earthy smell of hay and feathers greeted them as they stepped inside the owl emporium. Soft hoots and the fluttering of wings surrounded them. Maggie immediately gravitated toward a majestic eagle owl perched on a stand.
"Look at this one," she said, her voice reverent. "Such strength in its beak. And those talons—magnificent."
Petunia, standing beside her, smiled. "I thought you'd appreciate this place, Maggie. It's your kind of zoo, isn't it?"
"Zoo?" Maggie repeated, her tone almost offended. "This is far more specialized. These creatures are hunters—partners, not pets."
Meanwhile, Harry was drawn to the back of the shop, where a snowy owl perched silently on her stand. Her piercing yellow eyes locked onto his, unblinking and calm. He felt an instant connection.
"This one," he said softly.
The shopkeeper approached, smiling. "Ah, you've got a good eye, young man. She's a snowy owl. Female. Very loyal and intelligent."
Harry turned to Dudley. "What do you think?"
Dudley smirked. "Figures you'd pick the one that looks like she'd tell you off for being late."
Everyone laughed, and Harry grinned. "She's perfect. I'm naming her Valkyrie."
"A strong name," Vernon said approvingly. "Suits her."
The shopkeeper helped them arrange for Valkyrie to be sent home safely, and as they stepped back onto the bustling street, Maggie was still marveling at the variety of owls she had seen.
Their next stop was the Hogwarts Honors Shop. Vernon and Harry had been planning this visit, eager to inquire about elective subjects. Inside, Katie Holland greeted them warmly.
"Back so soon?" she asked with a smile.
Harry explained their query about electives, and Katie nodded. "Absolutely. Many ambitious students opt to test out of subjects like Arithmancy or Astronomy. The curriculum at Hogwarts is flexible; it's designed to support self-motivated learning. If you qualify, you can advance quickly in some areas."
Vernon exchanged a knowing look with Harry. "That's exactly the kind of opportunity we're looking for."
Katie leaned in slightly, her tone conspiratorial. "If I may suggest, don't overlook Divination. Most students dismiss it, but it can be incredibly insightful. Take a look at the section on it in your tome."
Harry nodded, mentally adding it to his growing list of things to explore. "Thanks, Katie. That's really helpful."
Rejoining the others, they wandered down the lively street, pausing to admire street performers and colorful shop displays. Dudley was particularly amused by a pair of enchanted sneakers that danced on their own.
"Think they'd let me wear those in the gym?" he joked.
"Only if you want to be disqualified for magical assistance," Harry quipped.
Maggie, meanwhile, was examining a selection of magical maps. "This one shows where people who are registered in something called a proximity ward are moving? That's brilliant. I could use it for tracking animals in the field."
Petunia nodded thoughtfully. "It's fascinating how practical magic can be. I wouldn't mind something like that for work."
As the family strolled along, their arms loaded with bags, the warmth between them was palpable. They weren't just shopping—they were sharing an adventure, one that had brought them closer than ever before.
Harry, walking beside Dudley, couldn't help but smile. For the first time in his life, he felt like he belonged— in the magical world, now that his family was comfortable and fascinated by this world.
The group made their way to Flourish and Blotts, one of the most iconic stops in Diagon Alley. The towering bookshelves filled with endless tomes created an almost magical atmosphere of their own, enticing Harry to dive into a world of knowledge. Vernon, Harry, Dudley, Petunia, and Maggie split up briefly, each drawn to sections that piqued their individual interests.
Harry and Vernon gravitated towards the Arithmancy section, a neat row of books with titles like Magical Numbers: Patterns of Power and Prime Mysteries in Spellcraft. Harry pulled a couple of books off the shelf and began flipping through the pages. It didn't take long for both Harry and Vernon to recognize the familiar foundations of mathematics in this branch of magical study.
The books discussed concepts like Pythagorean triplets, the magical significance of prime numbers, and their interplay with astronomical alignments. Diagrams illustrated connections between numerical combinations and the creation of wards and rituals. Vernon raised an eyebrow as he noticed a chapter titled Advanced Magical Calculus in Spellcraft and Warding.
"Harry, this is just math," Vernon said with a chuckle. "With all the work you've done on calculus and your fascination with advanced concepts, this is going to be a walk in the park for you."
Harry grinned, feeling confident. "I think you're right, Uncle Vernon. Arithmancy might just be my strongest subject, considering my background. But we should still get the books to see what my classmates will be working on and to prep for any tests."
The two grabbed a comprehensive set of books, both the core syllabus and some advanced editions, and moved to their next destination.
The Ancient Runes section was even more imposing. Harry's eyes widened as he noticed the sheer number of books. Entire volumes were dedicated to individual runic languages, detailing their meanings, usage, and symbolic power. One set of tomes explained common runic arrays, while others focused on their application in spells, wards, and rituals.
What caught Vernon's attention was a prominent display of five massive tomes titled Runes That Should Never Be Combined. Another set of ten volumes was marked Publicly Known Combinations and Practical Uses.
"Blimey," Vernon muttered, flipping through a volume. "These authors don't hold back, do they? Look at this disclaimer." He pointed to a passage that read:
"Experimentation is encouraged for magical discovery. Should you fail, you'll lighten the burden of another fool attempting the same mistake."
Harry chuckled, noting the dark humor. "Sounds like Ancient Runes comes with its own set of risks."
Despite the complexity, Harry decided to take the challenge seriously. They added the required books to their growing pile and moved to the next section.
This section intrigued Harry greatly. He had already picked up a basic book on foci lore during their first trip, but now he wanted to explore what the elective offered in-depth.
Books were divided into topics like magical and non-magical materials and specialized tomes focusing on different types of foci: wands, staves, rings, amulets, and even gauntlets. Each category delved into the properties of the materials, their compatibility with different magic types, and the specific crafting techniques.
"Just look at the variety," Vernon remarked, scanning the shelves. "This alone could take years to master."
Harry nodded, but he decided to postpone delving too deeply into foci lore until he had a better grasp of Ancient Runes, which formed the basis of crafting magical foci. They moved on but made a mental note to revisit this area.
At Katie's suggestion from the Hogwarts Honors Shop, they next visited the Divination section, which was split into two areas. The first, taking up nearly ninety percent of the space, was labeled Practical Divination for All. The second, smaller section bore the sign For Those with the Gift.
Curious, Harry glanced over at the smaller section but found it uninviting and mysterious. Instead, they focused on the practical books.
Harry was surprised to find that Divination wasn't just about prophecies or visions. Most of the books in the larger section dealt with spells and techniques for scouting, surveying, and scanning surroundings, objects, or individuals.
Vernon looked pleased. "Harry, this subject could be your lifesaver in a new and unpredictable world. Reconnaissance is essential. Make sure you sign up for this as soon as it's available."
Harry nodded in agreement, realizing how useful the subject could be, especially in unfamiliar magical environments. "I will, Uncle Vernon. And yes, we'll thank Katie for the suggestion next time we meet her."
Curious about the elective Spellcrafting, they searched the shelves but couldn't find a dedicated section. They returned to the counter, where a young man with a name tag reading Frederick Blotts greeted them with a polite smile.
"Excuse me, Mr. Blotts," Harry began, "could you point us to the spellcrafting section?"
"Please, call me Fred," the man replied, smiling warmly. "Unfortunately, spellcrafting books are restricted. They're only available in select places, like the Hogwarts Honors Shop, Hogwarts or any reputable library."
This led Vernon to ask, "Is there a library here in Diagon Alley?"
Fred nodded. "There is one on the second floor of the Hogwarts Honors Shop, but it's only accessible to current Hogwarts students and alumni."
Vernon patted Harry on the shoulder. "We'll check it out once you've started school."
They made their way back to the counter with books on Arithmancy, Ancient Runes, and Divination. Harry decided to wait on Fociilore until he had a better understanding of runes. Aunt Maggie, selected several books on magical creatures, zoology, and their evolution.
"I'd love to see the Magical Menagerie next," Maggie said excitedly.
Petunia glanced at the clock. "Next week, Maggie. It's getting late, and we still have other errands to run."
Maggie nodded, albeit reluctantly, and the group left the shop, bags brimming with knowledge and a growing anticipation for what was yet to come.
LINE BREAK
After a hearty lunch, the family settled into the cozy sitting room, the warm afternoon sunlight streaming through the windows. Maggie was lost in her newly acquired books on magical creatures, Petunia was skimming through a text on magical plants and their potential applications, while Harry sat at the center table. Harry had arranged a small mountain of books in front of him, including the ones on Arithmancy they had purchased earlier that day and several advanced mathematics textbooks Vernon had encouraged him to buy a year ago when Harry was exploring the idea of a double major in mathematics and physics.
Vernon entered the room after dropping Dudley off at the gym. Still in his casual post-lunch demeanor, he looked at Harry, who gestured toward the seat beside him.
"Uncle Vernon, take a look at this with me," Harry said, nudging a particularly thick tome titled Foundations of Magical Numerology.
Vernon took the seat and picked up the book. "Alright, what do we have here?"
Harry flipped the pages to a section on prime numbers and their magical properties. "This is the basics of Arithmancy, or at least what Hogwarts students are expected to start with. It focuses on the significance of prime numbers in magical theory and their applications in spells and wards."
They began by reading the introductory explanation.
"Prime numbers are the building blocks of magical structure, holding intrinsic properties that interact uniquely with spell matrices. Their indivisibility represents the unbroken flow of magical energy, making them essential for stable rituals and wards."
Vernon hummed in thought. "Alright, that makes sense on a conceptual level. In mathematics, primes are fundamental too, but not for mystical reasons—they're just the smallest indivisible units. Let's see how they're using them here."
They flipped to the examples of prime triplets—sets of three primes like (3, 5, 7)—and how they could form basic spell arrays. The book explained that the arrangement of these numbers created a balanced "magical triangle" of energy flow.
Harry opened his Introduction to Number Theory textbook and pointed to a chapter on prime triplets and their mathematical significance. "See here? Prime triplets are significant in number theory because they're rare and have unique properties, like forming solutions to Diophantine equations. But this magical version is just… fluff. It doesn't explain why the triplets are significant in magical energy flow, just that they are."
Vernon nodded. "Exactly. In math, we can prove why these relationships work. But here, they're just asking us to take it at face value that these numbers are magically compatible. No deeper explanation."
The next section discussed Pythagorean triplets—sets of integers (like 3, 4, 5) that satisfy the Pythagorean Equation. The book claimed these triplets were key in creating wards and stabilizing magical circles.
"It's fascinating," Harry remarked. "They've tied magical balance to the geometry of these numbers, like how the right angle in a triangle is stable."
Vernon flipped to the relevant section in Harry's Advanced Geometry textbook. "Well, Pythagorean triplets are fundamental in Euclidean geometry. They're the simplest way to form a right triangle with integer sides. But again, there's no reasoning here for why that mathematical stability translates into magical stability. It feels arbitrary."
They spent some time drawing diagrams from both books. Harry sketched the magical arrays that incorporated Pythagorean triplets, which the Arithmancy book claimed were used in defensive wards. Vernon used the geometry book to overlay mathematical proofs onto the magical diagrams.
"This is clever," Vernon said after a while. "But it's almost like they've taken mathematical concepts and stopped short of explaining them fully. It's as if they're relying on the magical community's lack of mathematical knowledge to make it seem more mystical than it is."
Harry laughed. "Maybe that's why it's so fascinating to me. I can see the gaps, but I also see the potential if someone actually approached this rigorously."
The discussion moved to prime numbers and their applications in spell matrices. The Arithmancy book claimed that primes were used to structure the flow of magic because their indivisibility symbolized purity and stability.
Harry picked up his Abstract Algebra textbook and turned to a chapter on prime factorization. "Primes are also the foundation of number theory because every integer can be broken down into a unique set of primes. But here, they've skipped all of that logical progression and just said, 'Primes are magical because they're indivisible.'"
Vernon pointed to a diagram in the Arithmancy book that showed a spell matrix built around the prime sequence (2, 3, 5, 7). "This diagram is interesting, though. The primes are used as nodes, and the connections between them form what they're calling a 'magic web.'"
Harry examined it closely. "It's a lot like graph theory. The primes are the vertices, and the lines between them are the edges. But there's no explanation for how or why the edges work magically."
Vernon smiled. "If they'd gone through the effort of tying this to something like Euler's path problems or maybe even Fourier transforms, it'd feel more grounded. Instead, they're just throwing in primes and calling it a day."
Toward the end of the book, they reached a section on calculus in spell creation and rituals.
"This is where it gets interesting," Vernon said, leaning forward. "They're using differential equations to describe the flow of magical energy over time."
Harry opened his Differential Equations textbook and began comparing the equations. "It's the same math we use for modeling physical systems—fluid dynamics, heat transfer, even electrical circuits. They're just substituting magical energy for any other variable."
Vernon nodded. "Exactly. The equations work because they're universal. What's disappointing is that they don't delve into how magic behaves as a system. Are there limits? Can magical energy decay? Is there resistance or friction in the flow? These are the kinds of questions that would make this a real academic field."
Harry grinned. "Sounds like something we should explore ourselves."
After hours of comparing and discussing, the two leaned back, their table now cluttered with books, notes, and diagrams.
"Well," Vernon said, "if this is what your classmates are starting with, you're going to breeze through Arithmancy."
Harry nodded thoughtfully. "It's basic compared to what we've been doing, but it's also giving me ideas. If I can combine what I know from math and physics with what I'm learning here, I might be able to approach magic in a completely new way."
Vernon smiled proudly. "And that, Harry, is why you're going to excel. You're not just accepting what you're taught; you're questioning it and building on it. That's how breakthroughs happen."
They spent the rest of the afternoon refining their notes, creating what felt like a bridge between the logical world of mathematics and the mystical world of magic. Harry couldn't help but feel excited about what the future held.
LINE BREAK
The evening air was crisp, carrying the faint scent of freshly brewed tea from the kitchen. After dinner, Harry sat in the corner of the living room with a large book resting on his lap. The compendium he was poring over was hefty, its thick pages filled with ancient symbols and intricate diagrams of Elder Futhark runes. He had spent the last hour engrossed in its content, occasionally jotting notes on a pad beside him. The low hum of the dishwasher from the kitchen provided a soothing backdrop to the household's quiet buzz of activity.
Dudley, having returned from his daily workout and showered, strolled into the room, looking relaxed in a faded gym shirt and sweatpants. A light sheen of exertion still clung to him, but he seemed content after his workout and dinner. He grabbed a water bottle from the coffee table and plopped onto the couch near Harry.
"Still at it, huh?" Dudley asked, leaning back and cracking his neck.
Harry nodded, not looking up. "Runes are fascinating. They're the foundation for a lot of magical theory, and I'm trying to get a handle on how they interconnect. The Elder Futhark, Younger Futhark, Anglo-Saxon Futhorc—they're all subtly different but interconnected."
Dudley squinted at the book Harry was reading. "They look like ancient tattoos or something. What are they used for?"
"Everything, really," Harry said without looking away from the page. "Spell reinforcement, wards, enchantments. Each rune has layers of meaning, depending on how you combine them. It's like building blocks, or…" He paused, frowning in thought.
Dudley tilted his head. "Like what?"
"Like coding," Harry muttered absentmindedly.
Dudley straightened up, intrigued. He reached for another book sitting on the table: a compendium of Egyptian Hieroglyphics. Flipping through its pages, he took in the intricate symbols, each accompanied by explanations and diagrams showing how they combined into larger structures. After a few minutes, Dudley glanced up.
"This is just coding," he said with a laugh, shaking his head.
Harry looked up and grinned. "Told you."
Dudley nudged Harry with his elbow. "So… have you told Mum yet? She'd be all over this."
Harry hesitated, his smile faltering. "Not yet. I wanted a second opinion before I brought anything magical to her attention. Didn't want to overwhelm her."
Dudley rolled his eyes. "Oh, come on. Mum's a pro at this stuff. You think she'd pass up the chance to solve a puzzle, especially one as cool as this? Let's just show her."
Harry sighed, then nodded. "Alright, now that you're here, let's go talk to her together. She'll definitely understand it better than I do."
The two stood up and walked into the kitchen, where Petunia was just finishing loading the dishwasher. She looked up as they entered, her sharp gaze immediately catching the books in their hands.
"What's all this about?" she asked, drying her hands on a towel.
Harry stepped forward, holding out the rune book. "Aunt Petunia, can you look at this? I think it's something you'll find… familiar."
Petunia pursed her lips, her brow furrowing as she took the book. She pulled out a chair at the kitchen table, sitting down as she began flipping through the pages. At first, her expression was one of mild curiosity, but as she turned more pages, her brows rose in interest.
Harry and Dudley hovered nearby, watching her intently. After a few moments, Petunia reached for the Egyptian Hieroglyphics compendium Dudley was holding and began flipping through that as well. Her eyes darted between the two books, and she muttered under her breath, occasionally tapping a page with her finger.
After about fifteen minutes, she looked up at the boys, her face a mixture of astonishment and excitement.
"This is… programming," she said, almost breathlessly. "It's like coding—each rune or symbol acts as a command, and when you combine them, they create an output. Each of these runic systems is essentially a different programming language. It's brilliant."
Harry and Dudley grinned at each other, excitement lighting up their faces.
Harry nodded enthusiastically. "Exactly! That's what I thought, but I wasn't sure if I was just seeing connections where there weren't any. I knew you'd get it."
Petunia took a deep breath, closing the books gently as she looked at Harry. "Alright, bring me all the books you have on this subject. I need to see more before I can say anything definitive, but this… this is fascinating."
Harry's eyes lit up. "On it!"
He and Dudley raced upstairs, returning moments later with an armful of books on Galdrastafir, Cirth, Sumerian Cuneiform, Mayan Glyphs, Harappan Script, Chinese Oracle Bone Script, Celtic Ogham, and even Sanskrit. Petunia set them all on the table, neatly arranging them before she began leafing through them systematically.
For the next hour, the kitchen was quiet except for the sound of turning pages and the occasional hum of interest from Petunia. The boys sat nearby, waiting patiently. Dudley sipped from his water bottle while Harry jotted notes, glancing at his aunt occasionally with eager anticipation.
Finally, Petunia set down the last book and looked at the two boys, her expression thoughtful.
"It's exactly like coding," she said decisively. "Each of these systems has its syntax, structure, and logic, just like programming languages. Some are basic, like simple scripts, while others—like the Sumerian and Sanskrit systems—are incredibly complex, like advanced machine learning algorithms." She paused, tapping her fingers on the table. "I'll need to reference the common runic structure books to fully understand the magical context, but once I do, I'm confident I can teach this to you, Harry."
Harry beamed. "Really? You'd do that?"
"Of course," Petunia said, smiling warmly. "It's not much different from teaching you two coding since your younger years. Give me a week to go through these books and design a course structure. Once I've got the basics down, we'll start."
Dudley cleared his throat. "If it's like coding… I'd like to learn too."
Petunia blinked, surprised. "You would?"
Dudley nodded, looking a bit sheepish. "Yeah. I mean, Harry's going off to learn all this magical stuff soon, and I… I just think it'd be nice to learn something together before he leaves."
Petunia's face softened, and she reached out to pat Dudley's hand. "Of course, love. I'll make sure to include you too."
Harry grinned at Dudley. "Thanks, mate."
Dudley shrugged, but a small smile tugged at his lips. "What are best mates for?"
The three of them sat together for a while longer, the warmth of their shared bond filling the room. Despite the complexities of the magical and non-magical worlds, in that moment, they were just a family—curious, supportive, and ready to tackle anything together.
Endnote:
Some points to keep in mind—
I would be posting 3 chapters regularly every week.
I might drop bonus chapters occasionally on festivals and other such events.
I would be very appreciative for any review, suggestions and feedback that I would get considering this is the start of my journey too.