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Genius by the Numbers

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“I need to speak with Diana.”

“Haven’t you done enough harm?”

Mum leaned on the door, looking exhausted. Harry raised his eyebrows. If they were so tired of dealing with Diana’s magic all the time, they should have gone back to the one Healer who had helped Diana control her magic. It had worked until she met Riddle, and then somehow he had become necessary to her control.

“Whatever you think I did, it’s still less harm than shuffling me off on Sirius and Remus, indulging Diana in her little-girl dramatics, and deciding that everyone else in the family could know about things like the prophecy but leaving me out of it,” Harry said coolly. “Didn’t you used to enjoy that Muggle saying about reaping what you sowed?”

Unlike Remus and Sirius, Mum had obviously kept the prophecy at the forefront of her mind. She stared at him with her face going rapidly pale and her hand closing on the door as if she needed it to stand. “Who told you about that?”

“Riddle. He said that Diana told him about it. Bragged about it,” Harry added, before his mother could make some ridiculous accusation about him bullying the secret out of Diana or Violet. “One of the first things she told him.”

Mum closed her eyes. “You were never supposed to know.”

“Why? When I think you told Violet?”

Harry pushed on the door, and although she seemed as if she didn’t want to do it, his mother moved aside to let him into the house. “We didn’t know if the prophecy had been fulfilled or not,” she murmured, her gaze flitting up the stairs. Harry knew why. He could feel the tantrum that Diana’s magic was having from here. “There was always the chance that the war would start again, if You-Know-Who returned. We needed to restrict the knowledge to those who could be useful in the war.”

Harry stared at her, wondering how in the world two schoolgirls could be useful in the war, and then the Knut finally dropped. “Oh. So you decided that I couldn’t because I wasn’t the genius child you wanted.”

“There’s nothing wrong with not being a genius,” said Mum quickly.

“Really? You acted like there was a fucking lot wrong with it.”

“It was just—we needed to give our time to Violet and Diana. They both need so much help…”

Harry stepped past her, not wanting to hear the excuses, but apparently the sound of their voices had been enough to draw Diana’s attention. She was standing at the head of the huge marble staircase, her magic flaring out around her like the uncombed curls of her red hair. “You,” she said with loathing.

Oddly enough, the tone didn’t hit Harry as hard as it would have even a week ago. All he could think about was how much more passion Riddle could put into a single word than she could.

Well…of course. The clouds cleared from Harry’s eyes as he stared at Diana. She was just a teenager. An overindulged, spoiled teenage girl. She wasn’t the devil incarnate and she wasn’t a heroine. Of course she wouldn’t be a match for someone who had created Horcruxes when he was at least sixteen and made everyone in the Potter family dance to his tune for years.

Harry could be gentler with her than he’d thought he could.

“I need to talk to you, Diana.”

“What about? You already married the man I wanted for my husband, what more do we have to say to each other?”

“The ancient vow is gone,” Harry said. “I broke it with my Arithmancy.” He had to admit he was a little curious as to what their reactions would be.

Mum put a hand to her mouth. Diana’s face cleared, and she beamed with a force that would have made a power all on its own, and could have let someone fall in love with her with nothing of the Girl-Who-Lived nonsense in place, Harry thought, feeling sorry for her. “Of course that happened! When is Tom coming back to me?”

So they believe in my Arithmancy when it benefits them. It wasn’t a disappointment, though. It was about what Harry had expected.

“That’s what I need to talk to you about. He told me some things…” Harry let his voice trail off suggestively, and Diana immediately pounced on it.

“Of course! Come into the sitting room, Harry.” Diana ran down the stairs and towards the room where they’d held the pre-wedding party a few nights ago.

“Diana, I’m not sure—”

Tom sent him, Mum! Why he would he do that unless he was going to marry me? It’s strange he didn’t come himself, but maybe he knew how angry I was with him.” Diana marched into the sitting room, and Harry met their mother’s eyes evenly for a few moment before he trailed after her.

Mum didn’t follow.

They really do just let her ride roughshod over everyone, Harry marveled to himself as he sat down across from Diana. This conversation couldn’t be long. He had promised Madam Madstrom that he would stay an extra hour that evening if she let him have an extra hour off in the afternoon, but then again, it didn’t need to be long. He had some brutal things to say, and brutal things that Diana needed to hear.

Diana arranged her robes around herself on the couch in front of the fireplace, and stared at him impatiently. “Why didn’t Tom come himself?’

“He didn’t think he could put it politely.” Harry leaned forwards. “He told me about the prophecy that said a child born at the end of a certain month was destined to defeat Voldemort. And he told me that you have a piece of Voldemort’s soul behind your scar.”

Diana’s mouth fell open. Her face had gone more pale than Mum’s at the door, and more rapidly. She didn’t burst out weeping or screaming, but Harry thought it was a near thing.

Her magic struck hard enough to knock a vase from the mantel and grind the shards on the floor into powder.

“Calm down.” Harry didn’t raise his voice. He’d had plenty of time to think last night, and he was sure that part of the reason Diana’s rages lasted as long as they did was that her magic fed on the rage in other people. It agitated her, made her stronger. And everyone running everywhere and screaming and acting as though it was the end of the world when she was upset only made it worse.

You calm down! If someone—if someone had told you that you had a piece of your greatest enemy’s soul in yours—”

Harry looked into her eyes and thought, Zero, as hard as he could. The invisible ring snapped tight around Diana at once, and the furniture stopped shaking. Diana opened her mouth and kept it open.

“What happened?” she finally whispered.

“I thought of a zero, and it formed a ring that contained your magic. But more than that, I know you can control it, Diana. You just let it loose because it’s a way of getting what you want, and you’re used to getting what you want. But you can control it any time you like.” Harry kept his voice brisk, trying not to lean too hard on either his contempt or his sympathy. “You were controlling it just fine from the time you were seven until you were twelve. What happened?”

“It just went wild that year.”

Diana wasn’t looking at him. Harry made an educated guess, because he was pretty sure he knew what had happened. “You let it loose to impress Tom Riddle, didn’t you? And then it became tempting to use it to get what you wanted, like when you came home that summer and told Mum and Dad that you wanted to be betrothed to him as soon as you turned fifteen. And then it became harder to control because you weren’t trying to control it anymore.”

“It hurts to control it!”

“Then find a different way,” Harry said. “Did it hurt when I forced it back into your body just now?”

“No.”

Diana’s voice was barely audible. Harry nodded without feeling any particular sense of triumph. “You could use meditation or visualization, probably. But yes, you do have a piece of Voldemort’s soul behind your scar. Riddle was quite certain of it.”

“Is that the reason he didn’t want to marry me?”

Harry almost said yes, because it would be the perfect lie, but changed his mind. After all, he wanted to remove that shard of soul, and the last thing he wanted was Diana then immediately going off to Riddle and telling him she was “clean” and they could marry. She’d had her heart broken enough by the bastard.

Oh, really? Is that the only reason?

Harry leaned forwards and said, “No. He changed his mind because he decided that he liked the power he saw in me better than the power he saw in you. But since I destroyed the ancient vow, he’s having to behave himself and act like a decent person. Among other things, that means that he told me about the piece of the monster’s soul so I could remove it from you.”

You could remove it?”

“You didn’t distrust that I broke the ancient vow. You felt it a minute ago when I forced your magic back into your body. And now you’re going to doubt this?”

Diana bowed her head, but she whispered, “Why did he have to fall in love with you, and not me? What’s so bad about me?”

Harry felt an uncomfortable twinge of pity. He pushed that away just like he had the question he’d asked himself a minute before. Now wasn’t the time for either of them.

“I don’t think he’s in love with me. He told me himself that he was conceived under a love potion and he thinks that he’s incapable of feeling it. But he respects my power more than he respects yours. Partially,” Harry added as he saw her mouth opening again, “because I can control it, and I can do marvelous things with it. You break vases.” He nodded to the few shards still left on the floor.

Diana stared down into her lap, at her entwined hands, and finally whispered, “All right.”

“All right, what?”

“Remove the soul-shard.” She faced him and pushed her loose fringe back from her forehead to reveal the lightning bolt scar. “If you can.”

Harry nodded and drew the parchment he’d prepared ahead of time out of his pocket, ignoring the temptation to respond to her taunt. He smoothed the parchment out on his knees. On it, it bore the equation 7 – 1.

The power that he had almost grown used to feeling from it surged as he stared at the scar on Diana’s head, and then compared it to the figure of the 7 he had drawn. He spent a few minutes erasing parts of the original number and adding a jagged line here and there that would make it look more like the scar while still recognizable as itself. And he focused his mind, too, on the fact that this was the most powerful magical number, while the parchment warmed in his hand.

Then he lashed down the equals sign. The sheet leaped eagerly in his hands, while Diana blinked and stared at him.

On the opposite side of the equals sign, Harry wrote down, carefully, 0 + 6.

The air twisted and hissed near him, golden figures of the numbers lighting it up. Harry gestured with his hand at Diana’s forehead, and the magic turned, pointing to—

Something that screamed and began to engage in a frantic struggle.

Harry gritted his teeth and tugged harder with the equations, laying his hand over the numbers when they began to smoke and burn. He hadn’t thought it would be this difficult. The shard had probably been dormant inside Diana, but it appeared that he’d awakened it with his equations.

Well, then. I still have to pull it out of her if I’m going to do what I decided I would with Riddle’s Horcruxes.

The shard continued fighting him, but Harry focused on the shapes of the numbers in his mind, and slowly, with a wail, it floated out of Diana. She gasped and covered her bleeding scar with one hand. Then she began to cry.

Reckoning that would bring their parents soon enough, Harry focused on the zero in the joined equations. The 7 represented Diana’s scar, the missing 1 represented the Horcrux he had taken from it, the 6 represented the total number that had once existed, and the 0—

Represented the trap he was going to tuck the Horcrux in. He forced it down and down, smaller and smaller, into a ring that projected from his body and encircled him the way he had forced Diana’s magic to rotate around her. It took much more effort than he’d planned on, and the wailing in his ears sounded louder and more aggressively, but the shard finally faded into the trap-ring. Harry gasped and opened his eyes.

He would have to concentrate on the zero the rest of the way back to his flat, he knew, or it might well escape from him. He had no idea what effect a free-floating soul-shard would have on the world, and no desire to find out.

His parents were standing in the door of the sitting room, as he’d expected. But it seemed they’d had enough sense not to interrupt what Harry was doing while he was still doing it. Now, though, his mum gave him a dirty look and bustled over to hug Diana gently, while Dad turned and stood between them and Harry.

“What were you doing to Diana?”

“Removing the Horcrux that was trapped in her scar,” Harry said, and rolled his shoulders. He didn’t know if he had actually hunched them in defense while he trapped the shard, or if it was just a physical representation of the magical effort he had exerted. He supposed it didn’t really matter.

Dad paled dramatically the way everyone seemed to be doing today. “There wasn’t a Horcrux trapped in her scar.”

“According to Riddle, there was.” Harry nodded to the trap-ring surrounding him before he remembered that no one else would be able to see it. Harry could, clearly watching the dark zigzag of the soul-shard tumbling around him in a never-ending circle, but Dad was glancing right past it.

“And you trusted him?”

Harry shrugged and stood up. “You were going to trust him to marry Diana.”

“You married him yourself. His actions the other day suggest there’s something fundamentally untrustworthy about him.”

Harry gnawed his lip to keep from laughing. If only he knew. “I broke the ancient vow with my Arithmancy. He could come back now and marry Diana, but that’s not what he has in mind.”

“And you? What do you have in mind?”

Dad asked it challengingly, as if he assumed that whatever it was, he would automatically disapprove of it. Maybe he would, at that. Harry shrugged again. “Dispose of this Horcrux and go on living my life the way I want. Develop my Arithmancy and get some of it published. See what people can tell me about it.”

Dad glanced over his shoulder at Mum and Diana—Diana was mumbling something like “a headache that I never knew I had”—and motioned to Harry with his head. Harry followed him out of the room, ready to listen to what he had to say, although he doubted he would be impressed by it.

“Don’t you think this pretense about your Arithmancy has gone far enough?” Dad asked when he had the sitting room door closed behind them. “You can’t do what you’re saying you could.”

“Yes, I can.”

“There wasn’t a Horcrux. You didn’t take it out. You didn’t crack Heller’s Theorem or come up with some new form of Arithmancy. You couldn’t do something like that.”

Harry looked steadily into his father’s eyes, looking for some kind of understanding, and found—

Fear. Stark, unyielding fear, the kind that Harry hadn’t felt for years. Even his anger that he’d felt a few days ago had been, well, anger. The prospect of being rejected by his family had made him angry, had saddened him, but this wasn’t the kind of terror he was used to experiencing. He hadn’t when he had thought the ancient vow might have bound Riddle to him forever, either.

His mum and dad had staked everything on being right about the intelligence of their children, the celebrity of their children, the conditions of their children, and their own decisions. Facing up to the truth Harry was telling them would have been harder than continuing to live with the consequences of those decisions.

Harry felt an odd satisfaction. It wasn’t a positive understanding, but now he understood them.

“If that’s what you need to tell yourself,” he said, “that’s what you should tell yourself. But I advise you to start working with Diana on meditation and Occlumency again. She was doing all right with those kinds of techniques before she met Riddle. And he’s sure as hell never coming back to her again.’

He turned away before Dad could respond and crossed the entrance hall to the front door, his step oddly light. At least he didn’t have the chains of fear weighing him dow.

“Harry?”

Harry glanced up and gave Violet a reserved smile where she stood on the stairs. “Hullo.”

“Can you talk to me more about Arithmancy and what you did?” Violet’s eyes were fixed on something that seemed to be Harry’s stomach, until he realized that she did act as if she could see the Horcrux-shard rotating around him. “I was studying Heller’s Theorem again today, and I realized that if you had cracked it and thought about the resonances, your theory would work.”

“Sure,” Harry said, grateful that it didn’t seem if he’d have to sacrifice his relationship with his youngest sister. “But not right now, okay? I have to go talk to Riddle about what we’re going to do next, now that I’ve broken the ancient vow.”

“Then you can do things like that with it. These shifting equations are good for something after all.” Violet gave him a determined nod and trotted up the stairs again, probably to go back to her equations and work out how that could be done.

Harry laughed quietly, and exited the house.

*

“Thank you for letting me come to you.”

Harry took a long moment to watch Riddle, who once again was sitting on the other side of the table in his flat above the Magical Menagerie. Riddle was toying with something in his pocket that was probably the Horcruxes. His head was bowed, and he hadn’t met Harry’s eye during the entire five minutes he’d been there.

It bothered Harry, made something deep inside him clatter and jangle like a chain.

He didn’t want to see Riddle like this. It was ridiculous, given what he had done, who he had been, but Harry didn’t want to see Riddle humbled and broken.

Neither did he want to change him in the way Riddle had asked for, to mold him like a clay sculpture—

Harry shuddered, and the Horcrux still circling around him in its trap-ring oriented on him and tried to wriggle into his soul. Harry repelled it with a little more concentration on the figure of the zero, more irritated than anything. Just because it had spent the past sixteen years surviving in Diana’s soul didn’t make him prey for it.

Harry swallowed and said, “You were right.”

Riddle looked up slowly, his dark eyes guarded and hollow. “About what?”

“About how using the equations to change myself into a person that my family could have respected would have been wrong.” Harry swallowed again. “And using equations to change you would be the same thing.”

Riddle watched him closely. “So this means that you will tell me to leave?”

He sounded dead, and Harry winced away from it. Even when he had most hated Riddle, he would never have wanted to see him like this. Passionless, voice filled with ashes.

“No. I have an alternate plan, if you’ll accept it.” Harry condensed and shifted the trap-ring, and laid the soul-shard that had occupied Diana’s scar on the table between them. Riddle stared at it in silence. “I plan to combine all the Horcruxes back together as one, pulling them out of their objects the way I did this one. And then I plan to stitch your soul back together.”

Riddle shuddered. He was silent, and Harry couldn’t read the expression on his face, except that the living intensity was back in his eyes.

“Do you approve of that?” Harry added.

Riddle looked him right in the eye. “And what would happen to the person I am now?” he asked. “What would happen if I no longer loved you, once I had my whole soul back?”

“You don’t even know if it’s love now.

“I have had time to think about it. This combination of awe and admiration and desire to be close to you and to do something that will benefit someone else more than myself, for the first time in my life…I do not see what else it could be.”

Harry touched Riddle’s hand, a quick, fleeting touch, and ignored the way that Riddle’s fingers turned upwards as if to close around his. “I think that you’ll be a better person with a whole soul, not a mutilated one.”

“If you are wrong?”

“Then I’ll either let you go or do everything I can to stop you, depending on what kind of person you turn out to be.”

“Genius or madman,” Riddle whispered. He closed his eyes. “And you cannot promise to love me.”

“I can say that I would be more likely to love someone with a whole soul, even if he’s different, than I am someone who has Horcruxes,” Harry said. “And it would show me that you have changed, that you really don’t plan to go back to the murderous tyrant that Voldemort was trying to become.”

“You can forgive my sins that easily?”

“They’re not mine to forgive. I was a kid during the war. I didn’t even get personally hurt—”

“My older self attacked your sister, and ensured years of abuse and neglect.”

Harry shook his head a little. “That was my parents’ anxiety about having a celebrity child and then a child like Violet to manage. They spoiled Diana. They could have done something else. But I’ve washed my hands of them so thoroughly that I just feel a little sorry for them.”

Riddle looked as if he didn’t know whether to smile or be infuriated. “You would. You are that kind of person.”

“Yes, I am.” Harry studied him. “Will you let me heal you?”

Riddle spent long moments thinking about it. Harry didn’t rush him. It had to be his decision, in the end. And what Harry was asking him to do was not a mutilation, but still a profound change.

“I would no longer be immortal.”

Harry nodded. “I would combine all the Horcruxes back into you. And if you ever tried to create another one, I would have nothing to do with you ever again.”

He’d thought earlier this afternoon that that would probably make an effective threat, but then he had scoffed at himself. Riddle wanted immortality more than anything. What was going to keep him from promising right now, and then breaking his promise later, when his fear of death grew strong again?

But Harry would at least offer him the chance. Indirectly, Riddle had been the means of freeing him from the fear that consumed his parents, and his stupid desire to please them. He deserved the chance.

Riddle met his gaze, his eyes like leaping flames. “You are worth it.”

Harry found himself having to grip the edge of the table so that he didn’t fall. Riddle blinked and stared at him in return, his eyebrows rising a little. “Are you well?”

Harry licked his lips and didn’t answer, while winds of surprise and other emotions tore through his soul.

Riddle had chosen him over immortality, when the thing he feared the most was death. Holy shit. Holy shit.

Harry closed his eyes and calmed himself with the reminder, again, that Riddle could always break the promise he’d made later. But he had to know that Harry was serious about walking away from him if he made another Horcrux. Maybe…maybe it would be enough for him if Harry remained his friend, or gave Riddle the chance to impress him.

He opened his eyes, and Riddle had a small smile on his face, as if he knew what Harry had been thinking. He said nothing, however.

“Do you want to wait?” Harry asked. “Or do you want to do this tonight?”

Riddle sat up at that. “I had assumed that you would require more time to design the ritual that would restore the Horcruxes to my soul.”

Harry snorted. “The design’s not that hard part. I just had to come up with seven equations, one to represent you and the others to represent all the Horcruxes that you’d ever made, and means to combine the six equations with the one that represents you for a good outcome…what?” he added defensively, because Riddle was laughing without making a sound.

“No one else in the world would be able to say that the design is not the hard part when they are talking about a ritual to stitch Horcruxes back into someone’s soul.” Riddle gazed at him with eyes that had gone gentle. “But you, my dear, my darling Harry, have grown so used to breaking the laws of magic that for you it truly is not difficult.”

Harry flushed at the praise, and met Riddle’s eyes for only a moment before turning his head away. “The hard part is going to be the doing,” he said, and because he fought to hold it in that register, his voice sounded relatively normal. “I thought we’d do it at the ritual circle in the Forest of Dean. If you have no objection?”

“Why would I? You are obviously comfortable with that circle, and it will make the resulting ritual more powerful.”

“Yes, but it’s the place where I broke the ancient vow. I thought you might associate it with pain. Bad memories,” Harry added, because Riddle’s face was so blank that he truly didn’t seem to understand what Harry was talking about.

“How could I ever associate the touch of your magic with something I did not want to feel?”

Harry rolled his eyes and stood up. “Okay. Bring the Horcruxes. And damn, Riddle. You have it bad.

“I think I do. Having never been in love before, I wouldn’t know.”

Harry flushed again, traitor that his skin was, and Riddle laughed aloud and glided away from him, the silken bag rustling in his pocket. “Shall we Apparate?”

*

Harry stood in the middle of his ritual circle, this time with the boundaries built with stones set in stacks of two, and a Lumos Charm beaming from the end of his wand, which he had set upright in the dirt near the boundary. He wouldn’t be using his wand for this. He held the same sharpened stick that had scratched the numbers in the dirt the day he had broken the ancient vow.

It was more powerful this way, more symbolic, to achieve the impossible with the tools he had already used to achieve one kind of impossibility.

Riddle’s quiet, waiting presence near him was almost a distraction, but Harry wouldn’t let it actually become one. That would hurt more than himself, and Harry did actually care about not harming Riddle, now that he had placed his life—his soul—in Harry’s hands.

When Harry was as grounded and centered as he would ever be, he opened his eyes. Riddle stood in the center of the circle, his attention fixed on Harry the way it had been ever since they left the flat.

The sensation didn’t disturb Harry now, though. He had passed into full acceptance of Riddle’s devotion. It was the only thing that would allow this ritual to work in the first place, after all, given what he had admitted.

“Hold still,” Harry whispered, and used the sharpened stick to scratch the first equation into the dirt around Riddle, moving in a small circle, the perfect, enclosed shape, a trap and container of its own, like the still invisible and rotating ring that held the Horcrux shard he had captured from Diana.

Riddle began to frown after he had scratched the first two numbers, and Harry thought he knew why. He hadn’t drawn plus signs between them, and the two numbers were also the same ones. 7 and 7 and 7, all the way around Riddle’s feet.

Seven of them, in fact.

Harry stopped when the sevens were drawn and stood contemplating them a moment. They weren’t perfectly identical, but as much as he could make them given that his drawing tool was a stick and his parchment the dirt. He nodded and placed an equals sign in the gap between each one of the pairs, where they would have had plus signs if this was a regular equation.

The resulting hum of power this time was more like a deep, loud gong that rang through the earth. Riddle stared at him in fascination.

Harry nodded to him. “Give me the bag with the Horcruxes.”

Riddle handed it over without any hesitation, which Harry barely refrained from swearing at him for. But he turned away from Riddle and dumped the Horcruxes on the ground, and then he had to deal with the reek of the magic rising out of them.

The diadem was spinning in place, in fact, and the handles of the cup squirming. The serpentine shape on the front of the locket twisted back and forth. Perhaps they knew that they were only a few minutes away from destruction.

Harry called upon another zero to create a trap-ring which grabbed the cup under one of its handles and floated it towards the far left corner of the ritual circle, almost to the boundary. Then he crouched beside it and began to draw fours all around it, for the four legs of the badger pictured on it, and the strength and stable foundation of the newborn soul that he would make for Riddle.

He drew twelve 4’s, again as nearly as identical as he could make them, and this time, he put the plus signs between them. By the time he got almost to the end of the circle, the power was rearing and snarling around him. Harry thought he could hear more than a trace of a badger’s growl in it.

Harry sealed the circle with a single 1, pointing like an arrow at the circle of sevens around Riddle. The cup immediately rolled towards the numbers as if to smudge them.

Harry laughed, and the cup rebounded from the shimmering power of the circle of thirteen.

Grinning, Harry turned and trapped the locket to send it to its destination next.

The locket took its position in the far right side of the circle, “opposite” from the cup as much as it could be, and the serpentine shape made of emeralds began to actually slither off it. Harry shrank the trap-ring around it until the whole thing was rattling futilely in the cage of a zero, and began to draw in the dirt around it again, sevens and the lazy, snaky nines he had meditated on the night before.

Three of the seven, three of the nine, and the one to seal the circle. This time, the power hissed and danced around him and opposite him, sometimes seeming to answer the call of the locket, and sometimes Harry’s own call.

It didn’t matter. Harry was master here, and he was sure of it.

He turned to the diadem.

It had apparently decided that it wasn’t going to wait to be imprisoned like its brethren. The silver shape of its twisted back on itself, and a shadowy eagle burst out of it, swooping towards Harry with talons extended and a loud shriek tearing from its throat.

Two minus one equals one, Harry thought smugly, and one of the eagle’s wings vanished. It careened towards the ground, limited by the shape it had chosen, and Harry ring-trapped the diadem and sent it to the lower right corner of the circle. Then he stalked over to it and began drawing the long, patient circle of twos and threes around it that he needed. Two, for the wings. Three, for wings and the sapphire in the middle of it, and as the second most powerful magical number after seven. Nine threes and nine twos, and then, twined around each other so much they probably looked like a knot, four ones. Separately, they were weak, but together, they could balance each other with the stability that Harry had always thought of four as having.

The diadem raged at him from within its circle, but Harry ignored it, and turned to the still-rotating Horcrux he had taken out of Diana.

He caught Riddle’s eye on the way, and blushed again at the fascination, the reverence, there. But he wouldn’t deny the spring was back in his step as he moved over to confront the smallest Horcrux.

It struck at him the moment he came within range. Harry felt the hooks of it trying to sink into his soul, and laughed himself breathless.

“Oh no you fucking don’t,” he said, and lofted the trap-circle over to the lower left corner of the circle, opposite the diadem and beneath the cup. The hooks had given him a perfect idea, and he hummed as he crouched and began to braid the strongest circle he could think of around the soul-shard to contain it.

Seven had to be part of it, because that was the shape he had used to remove the shard from Diana’s scar in the first place, but that didn’t mean he could replicate the circle around Riddle. Otherwise, they would exchange places, and he shuddered to think of what Riddle would be like with this Horcrux in control of his body.

Instead, Harry chose 17, a number that bore no particular magical significance in most traditions but consisted of the 7 shape he needed and an extra 1 as insurance, and braided the first circle of them around the shard, leaving large gaps between them and putting a plus sign in front of each one. Then he went back and added in a -10 after each one, a shape that took away the 1 but combined it with another 0, another representation of the shard’s trap-ring.

This way, when he finished, he didn’t even have to add a separate 1 to it the way he had the first two, which would have a left a weakness in the circle that the shard could have exploited. He stood back when he was done, a circle of seven complete equations, and panted a little, feeling good, nearly drunk on the magic, the blended song that was rising from five circles within the circle.

“Magnificent,” Riddle said, his voice thick.

“It’s about to get more so,” Harry said, and winked at him. He walked over to the right side of the circle again, this time midway between the locket and the diadem, and crouched to scratch another equation.

0+7, he wrote, his mind humming with it, again and again.

As he wrote, as he reached out, a ghostly shadow began to shine inside the circle. It solidified and darkened as Harry went on scratching, and by the time Harry had written seven of the equations, the way he needed to, it was so bright, or so dark, that it looked as if it was real. A gold ring, topped with a jagged black stone.

“Harry…”

Harry glanced over his shoulder at Riddle, and smiled. “What? Didn’t think I could do it? It was kind of stupid of you to agree, then.”

“I did not tell you what the ring looked like.” Riddle stared at it as if it was a dream, his right hand wringing silently open and closed at his side. Harry assumed his left hand was probably doing the same thing, but he couldn’t see it from this angle. “How did you…”

“A zero, the circular shape, for the ring,” Harry said, gentling his voice because Riddle looked utterly overwhelmed. “The sevens to call it here. Once I had the right equations, it couldn’t not respond.”

“I thought that piece of my soul entirely destroyed when Dumbledore obliterated the ring.” Riddle was still whispering.

“I promised you a whole soul.” Harry stood up and looked directly at Riddle. “Unlike some people who are currently standing here within a circle of equations, I keep my promises.”

Riddle’s eyes looked as if they held only darkness, only devotion. “I swear to you that I shall.”

Harry nodded, and paced over to the left side of the circle, between the cup and Diana’s soul-shard, and knelt to begin inscribing the last circle.

“Wait,” Riddle said suddenly.

Harry glanced over his shoulder, and saw Riddle leaning as far forwards as he could without leaving the joined ring of sevens. “What?”

“You said you needed six circles for the six Horcruxes, and I thought you meant to call the diary. But I am the spirit of the diary Horcrux. What are you going to call when you draw that circle?”

“Not what,” Harry said quietly, tilting his head while holding Riddle’s gaze, “who. And I think you know.”

Riddle closed his eyes. Harry nodded, and turned back to lay out the equations in the circle. This was a tiny circle, tightly-woven. It needed to be. Harry would require larger numbers to contain this one.

24, he wrote, + 24. Twice the number of twelve, his personal number of good luck and stability—twelve doubled, and twice the good luck.

A cold wind howled past him, and a sound like a maniacal shriek.

Harry wrote the 1 in the center of the circle this time, pointed inward, not outwards to the circle where Riddle stood. And as he wrote the last equals sign, his hand froze for a moment, pinioned and held in place by a cold, skeletal set of fingers.

Harry tore his grip away, and the hand crashed to the ground, and an arm formed behind it, and a looming figure formed, white-skinned and black-cloaked and red-eyed.

“Hello, Voldemort,” Harry said, rising to his feet.

The thing in the circle hissed and raged at him, but it was in Parseltongue. At the moment, Harry was glad that he hadn’t given himself the gift to understand it. It would only be a distraction.

He walked back over to Riddle’s circle, and saw that Riddle was swaying back and forth. Harry held out a steadying hand that he made sure didn’t cross the boundary of the equations.

“Are you all right?” he asked quietly.

“He is dead,” Riddle said. His voice was nearly inaudible; Harry was only sure of what he said because he was close enough to see Riddle’s lips move. “He was obliterated. I know he was. What—how did you draw him back?” He stared at Harry with what looked like true helplessness.

“I promised you a whole soul,” Harry said, not flinching, although Riddle helpless was more disturbing than Riddle almost prostrate with awe. “And this is my way of providing it.”

“But how?”

Harry grinned. “I’m using equations. When you want an equation to add up to something, there’s only one right answer depending on the other numbers you choose. I put down the equations, I chose my numbers, I called what I needed.”

“You are insane,” Riddle rasped.

“The irony,” Harry said, and turned his back on Riddle to study the whole of the circle. Yes, everything was ready, and although Voldemort was raging and the three Horcruxes Riddle had brought were rattling in their enclosures and Diana’s shard radiated cold black hatred at him, none of them could escape. Only the ring was still, and Harry thought it was probably raging in its own way, a way he couldn’t sense. It was the least vital thing in the circle. Voldemort had been human—sort of—and he was still a remnant of a living soul, while the ring was, in a way, the soul of an inanimate object.

Harry bowed his head and spread his hands. The ringing power, the blended, howling songs, abruptly focused on him. Harry nodded, and then folded the last three fingers on his right hand in towards his palm, quickly.

With seven fingers, he gestured towards the cup Horcrux, and then tucked his fingers on his left hand down so only four pointed, and then followed by tucking them all away except his extended thumb.

The cup Horcrux exploded. Harry felt the soul-shard rising from it, and felt the struggle begin the way it had with the one he had torn from Diana’s scar earlier this afternoon.

But this time, he had the ruthless logic of the equations on his side, and he only needed to open his lips, although against tremendous pressure from the magic-charged air, and snarl, “Forty-nine, you fucker.”

The circle of fours and the single one he had drawn around the cup ignited, the number 49 appearing in the dirt after the equals sign as if a giant’s hand had drawn them, and a thick dark line of soul streaked across the air towards Riddle.

Harry turned and saw Riddle flinch, but remain standing, firm in his acceptance of any fate that might come to him.

He is amazing.

The black line landed before it could strike Riddle, of course—Harry had had that much faith in his equations—and crossed one of the equals signs Harry had laid between the sevens, obliterating one line and changing it into a plus.

Riddle gasped, and sagged to his knees. When he looked up, there was a glittering gold tint to his gaze, as if he had swallowed the cup, but a second later, it was gone, He nodded, dazed.

Harry didn’t ask him what it was like to suddenly have a piece of soul attached to his first one again, because he was curious but they were probably running on a time limit here, and he could always ask later. He spun to face the locket.

The locket exploded before he could even point at it. The green snake that rose in the confines of the circle, hissing, was larger and more dangerous than any serpent had ever seen.

Not that it mattered. Harry had chosen the sevens and nines that surrounded it for a reason. He opened his mouth and sang them, his voice blending with the clattering gongs and howling winds of the circle, chanting the digits.

He reached the one at the end, and a circle of green and black adders surged up from the dirt, surrounding the locket-snake and binding it to their will. It fought them, with a fury, but by the time Harry called out “Forty-nine!”, they had won, and another line of black streaked across the circle and made an equals sign into a plus sign.

This time, Riddle dropped down in what looked like a dead faint. Harry inspected him narrowly, after making sure that one green snake and one black snake, left behind, had arranged themselves into the shape of a 49 on the ground.

Riddle struggled slowly back to his knees, and nodded dazedly at Harry. This time, there was a hint of green in his eyes.

Harry waited until it faded, and then faced the diadem.

It fought back with a shimmering nightmare shape as Harry thought of a three and then a two in his mind, and lit them with blazing mental flames that made the shapes all the way around it catch fire, too. Harry found that he couldn’t look directly at it. But that didn’t matter, not when the flames of his making surged up and lit the nightmare shape up with forty-five small and separate small blades of vengeance.

And now, the four ones.

Harry stomped his foot on the ground, quickly, four times. A 49 blossomed on the earth in front of the diadem’s circle.

The diadem screamed like a living eagle, and then reluctantly transformed and bent, a winged line that whipped another equals sign into a plus, and dropped Riddle like a stone.

This time, he lay there for long enough that Harry was afraid he had fainted and they might have to start the whole ritual all over again. But then Riddle slowly pushed his hands against the earth and raised himself up, and Harry saw the shining blue shifting in his eyes, the last remnants of the diadem’s sapphire.

“Harry,” Riddle whispered, his voice thick and dreaming.

Harry had already spun to face the soul-shard taken from Diana, though. It flickered sullenly at him, but did nothing as Harry muttered of seventeens and tens under his breath. It probably thought it would cross the circle of equations and then attack Harry, or Riddle, when it got close enough.

Sure enough, it swam into the air, a deceptively docile black line, leaving a sharp clear 49 on the dirt behind it, and crossed the distance to Riddle much more slowly than the other Horcruxes had. But Harry was watching for the little hook that it extended towards him, still trying to latch on to his soul.

Harry laughed.

The hook recoiled from him, chased by his laughter, which Harry knew would have been anathema to Riddle as he had once been and was anathema to Diana, who hated to be laughed at. The power of the circle of sevens around Riddle sucked it in, and it became part of the equation.

This time, Riddle only swayed on his feet, maybe because the shard had been smaller than the rest. Or maybe because he had been in contact with it before this, when it was occupying Diana and he had been romancing her. Who knew? The red tint in his eyes might have been the shade of Diana’s hair, but maybe not.

Harry smiled widely as he turned to face the ghost of the ring, and crouched on the ground with his hands raised in front of him, fingers touching, forming an empty circle.

He alternated that quietly with flickering seven fingers, and when he reached 49, the ring rolled across the line of the equations, and the 49 occupied the circle behind it, and the ring went on rolling until it reached the circle around Riddle and added itself to an equals sign. Harry shivered at the violent cold it dragged behind it, and turned to see what the effect was on Riddle.

His eyes had darkened to black, the color of the stone on the ring, but he was coping better than Harry would have expected, only feeling at the air for a moment as if he was trapped inside a cage. Then he nodded, and Harry knew he was ready.

They were both ready, for their toughest challenge.

Harry faced Voldemort, and ignored the sight of that open mouth cursing him in a language that he couldn’t understand. He closed his eyes and began to draw forth memories instead.

Himself, on a broom, diving after the Snitch. Violet learning how to walk. Neville laughing over a bubotuber that had sprayed both of them with its pus. Remus ruffling Sirius’s hair…

Harry drew them forth, and drew them forth, until he had thought of forty-eight memories of joy and love and amusement and cheer, and when he looked, they surrounded Voldemort’s circle in a shining wall. Harry could barely see him behind those seething red and golden bricks of light.

Now came the part of the challenge that would be toughest for him.

Harry turned to face Riddle. Riddle had been looking at the bricks of memories with a dazed expression, but he focused on Harry at once.

And Harry looked into his eyes, the eyes that had been smug when he made the ancient vow and dazed when Harry broke it and reverent so many times this evening, and thought, If this works, it might be that I could love him.

The positive memories of Riddle himself sketched a 49 in the air as dark fire. It settled like a dome on top of the brick wall, and then the memories whirled inwards and collapsed and tightened.

The sound of Voldemort’s voice fell silent at last. And then he surged into the air, a dark spirit, a wrathful one, but as much a part of the equations as all the rest, and swept past Harry and added himself to the last equals sign, making it a plus.

Riddle’s eyes turned white, the color of Voldemort’s skin, and then rolled back in his head as he fell.

Harry stepped lightly and quickly over to stand outside the circle of sevens, and used his foot to rub the last equals sign in the dirt, adding all the sevens and pointing to him, the source of the equations’ power.

In the middle of that humming, singing exuberance, Harry extended his hands and said gently, “Forty-nine.”

The words fell on the circle, and white light lifted silently into being around Harry.

It seemed to him that he was broken, drifting apart, in forty-nine pieces of his own, and every part of him fractured and split further and further, seven and seven and seven and seven and seven and seven and seven, ranging and bound, joyous and tragic, accepting and resisting, in love and in hate, soaring and grounded, Gryffindor and Slytherin, Harry and—

Riddle.

Harry opened his eyes, at last, and saw Riddle rising to his feet in the middle of what now looked like a little ridged circle of dirt. That was all right. The equation was drained, its power consumed, and what it had been put there for was done.

Tom Riddle stood there, and his eyes were his own. But his face was more lit with radiance than Harry had ever seen it before. Now he looked like a man who could be honest, and keep his promises.

And, maybe, feel love.

“Harry,” Tom whispered.

Harry held out his hand.

Tom crossed the circle to him, with jagged strides, and clasped him and kissed him. Harry returned the kiss with curiosity, interest, wariness, joy, amusement, gentleness, and smugness.

Tom drew back at last, his eyes darting over Harry’s face. “You will accept me?”

“You have a chance,” Harry corrected him, his breath fanning out gently over Tom’s lips. “I can’t promise that I’ll accept you at the end, or stay with you forever if you do something I don’t like. But you have the chance.”

“It’s more than I had before.” Tom bowed his head a little. “Thank you.”

Harry smiled and said, “Tom,” and watched Tom’s head jerk up and his eyes fill with wild joy.

“Thank you.”

Tom held his hands, and said nothing. He probably knew what Harry was saying thank you for, or thought he knew. For freeing him from his obsession with gaining his family’s approval, or giving him the chance to exercise his power.

But, in truth, it was also for the praise and the possible love that Harry could have from Tom, and teaching him that doing the impossible was something he could take pride in.

Harry glanced at his still-lit wand, and thought, Two becomes one, and watched the stones piled two deep fall, breaking the boundary of the circle and framing their way out of it.

And, perhaps, their path to the future, which could be predicted by no equation.

The End.