One Shot: An Equivalent Exchange

Hi all, 

Here’s the next chapter. I’m still working on the Pokemon Resurgence chapter, so here’s a one-shot in the meantime. I incorporated some elements from a previous story that was discontinued.

Chapter 1 - The Box of Curiosities

7th July, 1991

Harry Potter pushed himself back and forth on the swing, his trainers dragging through the worn groove in the dirt beneath him. It was early afternoon, but the playground was empty besides him. His cousin and his friends often gathered here, causing the other kids to stay away. Nobody wanted to deal with being bullied by the bigger, meaner boys.

He winced when his ribs protested on the upswing. The beating Dudley and Piers had given him was still causing him a lot of pain, and it seemed to be getting worse. He would probably be sore for a few days, but his body healed quickly, so he didn't expect this to last.

His stomach grumbled, reminding him he'd missed lunch. Not that the Dursleys would have noticed—or cared. Hunger was an old companion, one that Harry had long since learnt to ignore. Better to sit here on the swings than return to Number Four, where Aunt Petunia would find some excuse to withhold dinner anyway.

Harry lived with his aunt, uncle, and cousin in the house on Privet Drive, though 'lived' felt like too generous a word for his existence there. He slept in the cupboard under the stairs, surrounded by spiders and cobwebs. 

His clothes were Dudley's cast-offs, hanging off his scrawny frame like sails on a mast. The Dursleys made it clear that he was a burden they tolerated rather than a nephew they loved.

They'd told him his parents died in a car crash. That his father had been a drunk, his mother worthless. That he should be grateful they'd taken him in at all, despite being freaks who'd got themselves killed and left him on the Dursleys' doorstep like unwanted rubbish.

But that explanation didn't account for the strange things that happened around Harry. Things the Dursleys refused to discuss, punishing him for it instead. Like the time Aunt Petunia had tried to force a hideous jumper over his head, and it had somehow shrunk before it could touch him. Just last month, the glass at the zoo had vanished, allowing a boa constrictor to escape—right after Harry had been speaking to it.

The Dursleys called him a freak. Told him there was something wrong with him. And Harry, with no other explanation available, had almost begun to believe them.

Movement caught his eye. Harry looked up, startled, as a man appeared directly in front of him—not walking into view, but materialising out of thin air with a faint popping sound. Harry jerked backwards and tumbled off the seat, landing hard on his back in the dirt.

The man stepped closer. He was tall, middle-aged, with greying hair and an ordinary face. But it was his clothes that held Harry's attention—a bizarre collection of garments that looked like they'd been assembled by someone who'd never quite understood how people dressed. A purple waistcoat over a crimson shirt, paired with what appeared to be grey robes and bright yellow boots.

Harry had seen people dressed like this before. Passing strangers who'd stopped him on the streets and in the shops. They'd greeted him like an old friend, though Harry had never seen them before in his life. The encounters always ended abruptly when Aunt Petunia dragged him away, her face pinched with fury.

"Who are you?" Harry asked, pushing himself up onto his elbows.

"That's not important." The man’s gaze swept across the playground and the street beyond. "Where am I?"

"You don't know?" Harry climbed to his feet, brushing dirt from his oversized jeans. "This is Little Whinging, in Surrey."

"Never heard of it." The man's attention finally settled on Harry. "Since there's no one else around, I'm assuming you're the person that I need. I was compelled to come here and pass something along."

"Huh?"

The man reached into his robes and withdrew a small chest. The box was no larger than a shoebox, but its surface was covered in intricate carvings. The man thrust it towards him.

"Take it. I no longer have a use for it, nor do I have anything else I'm willing to sacrifice for its advantages. The Box of Curiosities belongs to you now."

Harry took a step back. "You must have the wrong person. I'm no one special."

"What do you mean?" The man's eyebrows rose. "You're a wizard."

The word hung between them. Harry furrowed his brow. "Come on, magic isn't real."

"Magic is certainly real." The man's tone carried a hint of impatience. "How do you explain how I appeared out of nowhere?"

Harry opened his mouth to respond, then closed it again, the words dying in his throat. The man had a valid point. One moment, the space had been empty, and the next, he'd been standing there, as solid and real as the swing set behind them.

And now that he allowed himself to really think about it, something remarkably similar had happened to him last year.

The incident at school. Dudley and his gang had cornered him during lunch break and chased him across the playground. One moment, Harry had been running, and the next moment, he'd been on the roof. 

The teachers had been baffled. Aunt Petunia had been livid. She'd collected him from school and locked him in the cupboard. She hadn't let him out for three days, except for bathroom breaks and to drink some water.

Aunt Petunia hadn’t been surprised. That was the thing Harry remembered most clearly. Angry, yes. Frightened, even. But not surprised.

Did his relatives know about magic? Was that why they called him a freak?

The man pressed the chest into Harry's hands. "Be careful with this thing. Although it can provide you with many extraordinary abilities, it has a ravenous appetite."

"What do you mean?"

"You need to exchange something of equal value to obtain something from the Box of Curiosities." The man stepped back. "Remember that."

Before Harry could respond, before he could ask any of the thousand questions suddenly flooding his mind, the man disappeared with a sharp crack.

Harry looked down at the chest in his hands. He was curious about what lay inside, but the man's words about him being a wizard mattered more.

A wizard. The word kept circling through his thoughts. Could it be true? It would explain everything—all those incidents the Dursleys had punished him for, locked him in his cupboard for. Not accidents or freakishness, but magic. His magic.

The idea settled over him like a blanket, simultaneously terrifying and exhilarating. If he were a wizard, then perhaps his parents hadn't been the worthless drunks the Dursleys claimed. Perhaps there was a whole world out there that he belonged to, a place where he wasn't a freak but simply normal. Or at least, normal for whatever passed as normal amongst people who could vanish into thin air.

But if magic were real, if he truly was a wizard, why had no one told him? Why had he spent nearly eleven years believing something was wrong with him?

Harry looked around the playground, suddenly aware of how exposed he felt. If there was truly something to this Box of Curiousities—and despite every rational instinct, he found himself wanting to believe there was—then he needed privacy to explore it properly.

Usually, he wouldn't trust a total stranger making wild claims and handing over mysterious chests. But a part of him, the part that desperately wanted this to be real. Because if magic existed, if he really were a wizard, then perhaps he'd finally found something that could help him escape the Dursleys. 

Harry tucked the chest under his baggy sweatshirt, trying not to make it obvious he was concealing something. He left the playground, heading towards the woods behind Privet Drive. 

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

Harry paused when he reached the large oak tree located in the centre of the woods. 

Nestled amongst those branches, about fifteen feet up, sat a small tree fort. The interior was roughly four times the size of his cupboard, with weathered planks forming sturdy walls and a slanted roof. A narrow wraparound balcony circled the front, its railing worn smooth by years of use. The fort was old, clearly built decades ago by someone who'd known what they were doing. 

Harry had discovered the fort two summers ago whilst hiding from Dudley and his gang. It had taken him three attempts to climb high enough to reach it, his arms shaking with effort, but once he'd pulled himself onto that balcony, he'd known he'd found something precious. He'd been using it ever since as a refuge when he didn't want to deal with the Dursleys. 

Harry pulled the chest from beneath his sweatshirt and tucked it carefully into the crook of his arm. The rope ladder hung down from the balcony. Harry gripped it with his free hand, testing its strength, then began to climb. The rope bit into his palms, and his ribs protested the movement—Dudley's earlier beating making itself known—but Harry gritted his teeth and pulled himself upward.

His trainers found purchase on the knots, and within moments, he'd hauled himself onto the balcony. Harry pushed through the small doorway and into the fort's interior.

The space was cosy in a way his cupboard had never been. A plastic crate served as a makeshift table, holding a few supplies he'd carefully hoarded: tins of food nicked from the back of the Dursleys' cupboards where they wouldn't be missed, bottles of water, a torch with batteries, and some books he'd found in a charity shop bin. A carrier bag against the wall held other odds and ends—things people had been throwing away that Harry had claimed as his own.

He sat on the sleeping bag and placed the chest down in front of him. 

"What am I supposed to do?" Harry murmured. "Just open it?"

The stranger's warning echoed in his mind—it has a ravenous appetite—and Harry's fingers hesitated over the lid. What if opening it triggered something dangerous? What if the whole thing was a trap?

But curiosity burned brighter than caution. He took a breath and lifted the lid.

Harry frowned as he examined the interior. At first glance, the contents didn't look like anything remarkable. The chest was divided into two distinct sections. On the left side sat a recessed area shaped like a hand.

On the right side was a spinning wheel, mounted flush against the interior. It was perhaps six inches in diameter, divided into more than two dozen segments like a pie chart. Each segment contained a small image. They were simple, almost crude, giving no hint of their meaning. A small handle jutted from the wheel's edge, and an arrow was fixed at the top, pointing downward.

Harry cocked his head, confused. What was he supposed to make of this?

Movement caught his eye. Text was appearing on the interior of the lid, black letters forming against the pale wood as though written by an invisible hand. Harry's breath caught. This was real magic, happening right before his eyes, impossible to deny.

He leaned closer to make out the words.

Welcome, Bearer of the Box of Curiosities.

This artefact operates on the principle of equivalent exchange. To receive power, you must sacrifice something of value. Place your left hand in the receptacle whilst holding your sacrifice in your right. The Box will assess the worth of what you offer.

Value is not measured in gold or material wealth. The Box judges worth by different means. A treasured memory may be worth more than a diamond. A cherished dream may outweigh a fortune.

For each accepted sacrifice, you will be granted one or more spins of the wheel. Each image represents a different universe from which you may obtain an ability. The specific power granted will be appropriate to your needs and nature.

Should you have multiple spins, you may choose to spin again for a different universe or request another power from the same world. You need not use all spins immediately—the Box remembers.

Upon receiving a power, you will be marked with a tattoo that represents your gift. This mark may be purely cosmetic, or it may serve as a focus to help you control your new ability.

Should you require additional knowledge or tools to use your power, close the Box and open it again. The necessary items or information will appear.

WARNING: Once you make your first exchange, you are bound to the Box. You must complete one exchange per year for seven years. After fulfilling this obligation, you may continue making exchanges or pass the Box to another.

Choose carefully.

The text faded, leaving Harry staring in disbelief. This was insane. Impossible. And yet, he'd just watched words appear from nothing.

Harry reached for the carrier bag against the wall and pulled out a can of Coke and a packet of crisps. He needed to think, to process what he'd just read.

The rules were both simple and terrifyingly vague. Sacrifice something valuable, get a spin, and receive power. But what was valuable to a magical box? And what happened if he failed to make an exchange each year? The message hadn't specified a punishment.

Harry crunched through a handful of crisps, barely tasting them. The wheel bothered him. Since the power was determined randomly, did it matter what the images represented? Could he aim for a particular segment, try to influence where the arrow landed? Somehow, he didn't think it would be that simple. And even if he could control where it landed, how was he supposed to know what power each image represented? 

The text had mentioned that the powers came from other universes. Were they actual parallel realities, places that existed somewhere beyond his understanding?

Harry shook his head and took a long swig of Coke. All his speculation was pointless. The real question was simpler: was he going to do this?

The Box was clearly magical—the appearing text proved that much. But was it dangerous? The warning about being bound to it for seven years gave him pause. Seven years of mandatory exchanges, of finding things valuable enough to sacrifice. What if he ran out of things to offer?

Which led to another problem: what did he have that was valuable? He was a poor orphan who slept in a cupboard. His relatives provided the bare necessities, and even that was stretching the definition. His clothes were hand-me-downs, and his possessions could fit in a carrier bag. The watch on his wrist was probably the most expensive thing he owned, and it was hardly worth anything.

Harry finished the crisps and stuffed the empty packet back in the bag. 

After another moment of hesitation, he reached out his left hand towards the receptacle. There was no harm in testing it, was there? Just to see what happened. He had the watch on his right wrist—maybe that would be enough to earn a single spin. He could try it, see what the Box considered valuable, and then decide whether to actually go through with receiving a power.

The moment his palm touched the smooth wood of the hand-shaped depression, warmth flooded through his fingers. The text on the lid vanished, and new words appeared:

Sacrifice Detected!

Foreign soul fragment located in the bearer's scar. 

Origin: fractured soul, forcibly embedded. 

Current state: parasitic, dormant.

Offered exchange: Remove a soul fragment in return for two spins.

This exchange requires only verbal agreement. 

Do you accept?

Harry's hand flew to his forehead, fingers pressing against the lightning-bolt scar that he'd carried for as long as he could remember. 

A piece of someone else's soul. In his head. 

The words swam before his eyes. Fractured soul. Parasitic. How did someone fracture a soul? How did it end up in his scar? The Dursleys had told him he'd received the scar in the car crash that killed his parents, but Harry seriously doubted that story now. A car crash didn't leave pieces of souls behind.

His fingers traced the raised tissue of the scar, and revulsion crawled up his spine. Something foreign was in his head, something that didn't belong to him. He didn't want it. Whatever it was, whoever it had come from, he wanted it gone.

And the Box was offering to remove it. For two spins, without requiring him to sacrifice anything else. Because the soul fragment itself was the sacrifice, something valuable that didn't belong to him.

If it had been his own soul the Box wanted, Harry would have refused immediately. But this was different.

"I accept," Harry said. "I agree to the exchange."

What happened next wasn’t something he was prepared for.

His left hand, still resting in the receptacle, became locked in place. An invisible force clamped down, holding him prisoner. Harry tried to pull back, panic flooding through him, but his hand wouldn't budge.

Then his scar exploded into pain.

Harry screamed. It felt like someone had taken a white-hot drill and pressed it directly into his forehead, boring through skin and bone and into his brain itself. The pain was beyond anything he'd experienced, worse than every injury in his life combined and multiplied.

Something was being torn out of him. He could feel it, a presence he hadn't known was there, suddenly thrashing and fighting as it was ripped away. The sensation was violating, invasive, like fingers digging into the most private parts of his mind.

He nearly went catatonic as the pain continued, his mind retreating from the overwhelming sensation, seeking darkness and oblivion. His vision went white at the edges. His throat was raw from screaming.

Then, as suddenly as it had begun, it stopped.

The pain vanished, and the invisible force released his hand. Harry collapsed sideways onto the sleeping bag. He lay there gasping, his entire body shaking.

It took several minutes for the trembling to subside. He could feel wetness on his forehead—blood, trickling down from his scar. With shaking hands, he felt for his glasses, which had fallen off during his ordeal, and put them back on. The world swam into focus.

Harry sat up and wiped the blood away with his sleeve. The bleeding had mostly stopped, with only a small trickle coming from the scar tissue.

He glared at the Box, resentment and fear warring in his chest. Was this what every exchange would be like? Because if so, he wasn't sure he wanted any part of it.

But the wheel was glowing softly. At the top, above the arrow, a number had appeared: a glowing numeral two. Harry stared at it, his anger slowly fading as excitement replaced it. The pain had been horrible, but it was over. And whatever had been in his scar was gone. 

Harry took a deep breath and reached out and grabbed the small handle on the side of the wheel. 

He gave it a gentle flick, and the wheel spun rapidly, the segments blurring together. Harry watched it spin, holding his breath in anticipation.

The wheel landed on an image of a man, with lines running through his body and ending in a spiral pattern just above his navel. What kind of power was this? 

Harry placed his hand back on the receptacle and instantly felt a sharp, burning sensation that started in his palm and shot up his left arm. He yanked his hand away with a hiss and shoved up the baggy sleeve of his sweatshirt. His breath caught as he watched dark lines appear on his forearm, spreading like ink dropped into water. 

The tattoo formed quickly—the same image from the wheel. The burning intensified as the design completed itself, each line searing into place until it was crisp and clear.

Harry examined it. The tattoo was actually quite cool, as long as he could hide it from the Dursleys. But what did it mean? 

Harry waited, half-expecting knowledge to flood into his mind or some dramatic transformation to occur. Nothing happened. He flexed his fingers, concentrated hard on the tattoo, even tried willing something—anything—to manifest. Still nothing.

Then he remembered the text. The instructions had mentioned something about requiring additional knowledge or tools. Harry reached forward and closed the lid of the Box, then opened it again.

The wheel and receptacle had vanished. In their place sat a slim book, no larger than a paperback novel. The same image from his tattoo was embossed on the cover. Harry lifted it out and flipped it open.

On the inside cover, neat handwriting filled the page:

Greetings,

If you're reading this, you've received access to knowledge from my world—a place where we manipulate chakra, the energy that flows through all living things. This book covers the fundamental nature of chakra: what it is, how it functions within the body, and the methods we use to gain control over it.

I should clarify something important. Your magic operates differently from our chakra system. Where chakra requires balance between physical and mental energy, your magic is more deeply rooted in mental will and the soul itself. The physical component is far less pronounced in your system. But it's still important.

The tattoo you've received will serve as a bridge. It will help you develop a structured approach to your magic using principles similar to our chakra network. Think of it as creating pathways and control points—giving form and direction to what has been, until now, wild and instinctive.

Study well.

Harry stared at the message, reading it twice more to make certain he understood. Someone from another universe—another world entirely—had written this specifically for him. Or at least, for whoever received this particular power. The idea was simultaneously thrilling and deeply strange.

He turned to the first chapter and began reading. The text explained that chakra flowed through a network of pathways throughout the body, concentrated in specific points called tenketsu. Diagrams showed the human form mapped with lines and nodes, illustrating how energy moved from a central core outward to the extremities.

The descriptions were fascinating. Chakra users apparently trained for years to sense their own energy, to feel the flow through their pathways, and eventually to consciously direct it. Basic exercises involved meditation and focused concentration, learning to recognise the subtle sensations of energy movement before attempting anything more complex.

Harry traced the diagram with one finger, comparing it to his own body. Did he have these pathways? The book suggested the tattoo would create something analogous in his magical system. 

He continued reading, absorbing information about chakra control exercises, the importance of proper breathing, and the relationship between mental focus and energy manipulation. 

Harry glanced outside. He'd been reading for over an hour, maybe longer. If he wasn't home when Aunt Petunia started preparing dinner, there'd be hell to pay.

He closed the book and looked at the chest. He still had one spin remaining. He could use it now and gain another ability from this same universe. The book mentioned dozens of techniques, different types of chakra manipulation. He didn’t know if he could replicate those techniques with magic, but the Box of Curiosities would give him something. 

But the smarter choice was to wait. He needed to understand this book properly, needed to actually develop some control over his magic using these principles. Rushing ahead to collect more powers without mastering what he already had seemed foolish. Besides, the Box had said he could save spins for later. They wouldn't disappear.

Harry tucked the book down the front of his jeans. The Box itself he left where it was, closing the lid and pushing it into the corner near his supplies. From what he understood, the Box was bound to him now. No one else could use it until he'd completed seven exchanges or... well, the message hadn't specified what else might break the connection, but Harry didn't fancy thinking about that too hard.

=-=-=-=-=-=-=-=-=-=-==-=-=-=-=-=-=-=

23rd July

Harry sat cross-legged in his fort with his eyes closed. The summer heat made the clothes stick to his body, but he barely noticed, too focused on the steady rhythm of his breathing. His hand rested palm-up on his knee, fingers slightly curved.

Beneath his skin, he could feel it—the flow of energy moving through his veins, responding to his will. He'd spent the last two weeks learning to recognise this sensation, to coax it from his core and outward through his arm.

Now came the difficult part.

Harry opened his eyes and channelled the energy through the pathways and into his palm. For a moment, nothing happened. Then a faint black glow emerged from his skin, flickering like candlelight before steadying into a soft nimbus that enveloped his entire hand.

A grin spread across Harry's face. He'd actually done it. 

When he flexed his fingers, the glow intensified. When he relaxed, it dimmed. It was his magic, no longer erupting in panic or desperation, but controlled and deliberate.

Two weeks. It had taken him over two weeks to reach this step, practising every spare moment he could steal away to the fort. But now he could finally move forward, start learning to manipulate his magic to perform actual spells instead of just manifesting it in raw form.

The colour intrigued him. According to the book, if this had been a chakra, black would suggest an affinity for yin release, or shadow style. Whether the same held true for magic, Harry had no idea.

From what he'd deduced through observation and experimentation, magic wasn't normally visible in this raw form. He'd never seen evidence of it during his accidental magic. Either his manifestation was unique to the chakra-inspired approach, or wizards simply didn't work with raw magic this way.

But he still knew so little about magic itself. About how it was supposed to work, what wizards could actually do, whether there were schools or books or teachers. He wished he'd asked the man who'd given him the Box where to find more information about wizards.

He thought about asking his relatives, believing they might know something about magic. But Harry wasn't ready to open that particular can of worms, not until he could perform proper magic to protect himself if things went badly.

Harry let the glow fade and flexed his hand, feeling the familiar ache of depleted reserves. That was another thing he'd confirmed through practice—his magical reserves were finite. Rest and sleep recovered it, and the book suggested that consistent practice would gradually expand his capacity and improve his control.

The chakra techniques mentioned in the book remained frustratingly out of reach. They didn’t work without an external chakra source to draw from; his magic simply wouldn't cooperate. The fundamental difference between chakra and magic was too great.

But that didn't mean the techniques were useless. There might be magical equivalents out there, spells that achieved similar effects. Or he could try developing his own methods.

Which led him to his current decision.

Harry pulled the Box from its hiding place in the corner and set it in front of him. He'd been planning to start experimenting with spell manipulation, to see what he could accomplish now that he had some basic control. But the more he'd thought about it, the more he'd wanted to see what else the same universe could offer. A technique tailored to work with the chakra system might translate better to his adapted magical pathways than trying to develop something entirely from scratch.

No longer hesitating, Harry opened the chest.

Text appeared on the lid immediately: You have one remaining spin. Would you like to receive another ability from the same universe, or choose a different world?

"Same universe," Harry said.

The wheel changed. The segments reorganised themselves, displaying new images. Harry studied them, trying to glean meaning from the simple illustrations, but they were too abstract.

He reached out and gripped the handle, and gave it a sharp flick.

The wheel blurred into motion. Harry crossed his fingers, hoping for something useful, something that would complement what he'd already learnt. The segments slowed, the arrow ticking past image after image until it finally settled on two identical figures standing side by side.

Harry frowned at the image. "What is this supposed to be?"

He placed his left hand in the receptacle. The now-familiar burning sensation shot up his arm, and he watched as dark lines appeared on his forearm, just above the previous tattoo. 

When the burning faded, Harry closed the Box and immediately opened it again.

This time, a large scroll appeared where the book had been. It was two feet long, bound with a simple cord. Harry lifted it out and unrolled it.

The moment his eyes focused on the first line of text, his head exploded in pain.

Information flooded into his mind—not words he was reading, but knowledge being forcibly uploaded directly into his brain. Images, concepts, procedures, warnings, all of it crashing through his consciousness faster than he could process. Harry's hands locked around the scroll, his body frozen as the torrent continued.

Minutes passed—he wasn't sure how many—before the flow finally stopped. The scroll crumbled to dust in his hands, disintegrating completely as though it had never been solid at all. Harry barely noticed, too focused on sorting through the mass of new knowledge now residing in his mind.

The Shadow Clone technique.

"I can definitely use this," Harry breathed.

His grin returned, wider than before. The magical world might have kept itself hidden from him, but he was no longer helpless, no longer waiting for someone to tell him what he was or what he could do.

He had control over his magic. He had a technique that could multiply his efforts. And he had an entire summer stretching ahead of him to master both.

Harry closed the Box and set it aside, his mind already full of possibilities.

So, what do you think? I always wondered what Harry would achieve if he could clone himself. 

Thanks for reading.