Miscalculation - Chapter 1

Summary-
For years Harry has gathered Unspeakables, scholars, and professors, the best in the field of Arithmancy, to complete a ritual he found in the Potter Family Tome. The goal, a one-way trip into the past. They've done the math. Let's hope no one forgot to carry the one.

1.

Harry stared down at the three relics before him. The Cloak, the wand, and the ring supposedly created by Death itself. There was truth in old stories, but finding it was never easy. The relics overflowed with Death Magic. Owning all three allowed him to summon them at will, regardless of where they were. Shockingly enough, they came to him even if someone else had them. Regardless of the legend following him, Harry didn't have as much experience as some others out there.

Hunting down the worst of the remaining Death Eaters, and the converts, pitted him against some dangerously talented witches and wizards. No one wanted to admit that Harry shouldn't have been out with the Auror squads, but who could tell The Man Who Won to stay out of it?

The first time he had been disarmed while wielding the Elder Wand had sent a spike of panic through his entire being. Harry and the wizard stared in shock when the wand refused to work. Well, the fact that the wizard had cut off most of Harry's right arm in the process was where most of the shock on Harry's part came from. The wand had vanished from the other wizard and appeared in Harry's left hand.

Unfortunately, regrowing limbs wasn't something that the magical world could do just yet. Bones could be replaced, but the complex network of nerves, muscle, and skin was too complicated. Instead, Harry paid one of the few remaining Dwarven Smiths to create him a new arm. He would have gone to the goblins, but they were still unhappy with him. Technically, he was on the same level as any other wizard after paying the fines, but Harry suddenly found that everything from them had tripled in cost and had gained as many fees as they could tack on.

Most of the Dwarves had entered the Stone Slumber and wouldn't be awake for another fifty years or so. Fortunately, there were still a few skilled Smiths around. They had made the bones from a special Mithril Alloy. He would have been left with a metal skeletal limb if not for a ritual that allowed people to replace parts of their bodies with those from magical creatures. It was originally created by a war-wizard to enhance soldiers. Only witches, wizards, and squibs could survive the process. A donation from Slytherin's Basilisk gave Harry an arm of iridescent black scales that functioned just as well as his original arm. The fact that it was highly spell resistant was a nice benefit too. Years of having Phoenix Tears and Basilisk Venom flowing through his body made the process even easier.

A simple glamour made it look like a normal arm, but he still switched to long sleeved shirts and took to wearing gloves after that. Hermione had gathered all of their friends to convince him to take a break from actively hunting Death Eaters to get some real training. It was hard to argue while his new arm was still tingling. The Dwarf had called it the Attunement Process. During the stretch of downtime, Harry worked on getting comfortable casting with his left hand until the new arm settled. It also gave him time to look at the world outside of hunting Death Eaters.

Magical Britain was barely limping along. Half-blood and first-generation witches and wizards had fled during Voldemort's rise. They were slow to return. Most had no plans to come back at all. Those that remained discovered that they still faced the same prejudices and obstacles. Magical Britain was going to vanish in the next fifty years if things didn't change.

It lit a fire in his soul. The Death Eater situation needed to be handled now. There were bigger issues to face. Once he was attuned to his new arm Harry trained with Aurors, Hit Wizards, and duelists from around the world.

Harry was a force of nature by the time he returned to the hunt. He studied the Black Family Tome and Potter Family Tome when he wasn't training or in the field. There were spells, rituals, and tactics that were created for the sole use of the respective family. He found a half-formed ritual in one of those study sessions that caught his attention.

Time Travel.

The ritual looked sound. It was abandoned when the creator discovered the amount of power it would need, as well as the fact that it would send them back physically. They wouldn't take over their younger body and it was a one-way trip. He had taken the ritual to Hermione, who then brought in Professor Vector, who then reached out to another professor, and so on until they had gathered a team of experts including a couple of Unspeakables. The group was magically bound to secrecy, sworn directly to the Potter Family Magic. None but those Harry, or the future Head of the Potter Family, would even know of the ritual. Everyone else would forget it once they left the workshop.

After years and years, the ritual was finally ready. It was a one-way trip into the past. The goal was set the summer before his Fourth year. Voldemort wouldn't have a functional body yet, his followers were focused on their own goals, he knew the location of all the horcruxes, and the Ministry was primed for someone to take over.

Hermione had been the one to convince him about the Ministry. Since the end of the war, she had been working on getting the Magical Government in order. It dug its heels in and fought everything including the tiniest change. Laws were still in favor of Purebloods. The half-blood and first-generation population of witches and wizards faced harsher punishments, stricter laws, lower wages, and were treated only slightly better than magical creatures. It was a miracle that there hadn't been more Dark Lords. Things would have ended much worse if Voldemort had taken a slightly different approach. They only way to fix the Ministry was to start over. Harry was the best option with his knowledge of the future and magical prowess.

He would need to be careful, there would be two Harry Potter's once he arrived. With any luck, he would only need to be at Hogwarts long enough to get the diadem. He didn't plan on interacting with his younger self or Dumbledore any more than was absolutely necessary. Harry had gone from idolizing the wizard, to hating him for all the manipulation the old goat had done in his life and had finally settled on irritation. He would definitely take the option to smack the man if it became available but did not plan on going out of his way to fight the old wizard.

"Are you ready?" Hermione asked.

Harry smiled at his friend and nodded.

He stood out surrounded by Unspeakables and other serious looking magical folk as he was the only one naked. They were playing it safe as they didn't want any other material to complicate matters. One of the Unspeakables had mentioned they might need to remove his arm just in case. It would have carried a lot more weight if that specific wizard hadn't tried to get Harry to remove the arm all the time. The Unspeakable desperately wanted to study it. Thankfully, the arm had fully integrated to his body, and his magic, so it wouldn't cause any issues. If anything, the Mithril Alloy made Harry's magic flow easier than before.

Harry scanned the ritual circle. The Cloak, Wand, and Stone were placed at specific locations in the array. The Hallows were the perfect artifacts to power the ritual. He wasn't sure if the trio were actually created by Death. What he did know was that each artifact was beyond powerful and grew stronger when used simultaneously. The Elder Wand packed a punch on its own, but it also seemed to syphon a small amount of magic with each spell that was used and added it to the ever-growing reservoir. The Resurrection Stone could summon and speak to the dead. When used with the Cloak, the stone would temporarily turn him incorporeal. If just the Elder Wand was used, then it could banish, bind, or create all sorts of undead. A combination of the Cloak and Wand made any spells invisible, unstoppable, and completely untraceable. Using the three of them to power the ritual was their best shot at getting it to work.

The Chamber of Secrets had been the perfect location. Hogwarts was built on the nexus of Ley Lines which not only gave an extra boost of power but helped stabilize things as well. The Chamber was detached just enough from the castle to avoid mingling with the vast multitude of enchantments within. That was also one of the reasons that people could apparate to and from the Chamber without tripping the wards. Thankfully, it could only be done once a person had been there, otherwise Voldemort would have had an unobstructed path into the school. Voldie would have had to take each of his minions there at least once and he wasn't the type to share.

Hermione came to a stop beside him. Her arrival pulled him out of his thoughts.

"You'll take care of them?" Harry motioned to the relics carefully arranged around the ritual circle.

"Yes." Hermione nodded. "I'm going to toss them in the veil once the ritual is over."

"Thank you." Harry pulled her into a hug.

For once, it was Hermione who broke away first.

"I love you, Harry." Hermione said. "I always have, and I always will, but I do not need your other wand rubbing against my leg."

"You love me?" Harry teased.

"Like the annoying little brother, I never wanted." Hermione teased right back.

She shifted to the side and gave him a proper hug.

"Be careful." Hermione whispered.

"I'm always careful." Harry chuckled.

Hermione tapped the thin scar where his skin transitioned into scales.

"Perfect example." Harry nodded. "Imagine how bad it would have been if I hadn't been careful?"

"Get your naked bum in the circle." Hermione rolled her eyes. "I'll miss you."

"I'll keep an eye on little Hermy, Harry, and Ronnie-kins." Harry gave her a kiss on the cheek. "Their future will be better than ours."

"I know." Hermione didn't fall for the bait. "You made sure to say goodbye to everyone?"

Harry nodded. Neither wanted to acknowledge the fact that by going back, he was erasing the future. In truth, it was only Harry who knew about the project outside of the workshop and ritual space. Everyone else forgot what they were working on once they left. They knew that they were working on something, but it was hidden behind a magical vow so they couldn't discuss it with anyone.

Hermione watched as her best friend carefully navigated the various runes carved into the floor as he made his way to the center. She took in his naked form in a clinical manner. Hermione could admit that at one point she had a crush on Harry. Somewhere along the way the love she felt for him shifted away from romantic. Still, she could objectively say that Harry had grown into a handsome man. She tried not to linger on the various scars on his body or replacement arm. The iconic lightning bolt on his forehead was a hair-thin line these days. She had to purposely look for it to see it anymore. Instead, she watched him gracefully approach the center of the circle.

She looked down to the three relics arranged around the circle. A sigh escaped her lips as she slipped her hands into her pockets. The plan was to take them to the veil once Harry was gone. They didn't know what issues it would cause if they were destroyed before then. Something crinkled in her pocket.

Hermione pulled out a pink Post-It note. A complex equation she didn't recognize was scribbled on it. She studied it for a moment. Realization rapidly turned to dread as her eyes ran over the numbers. It was part of the last bit of Arithmancy for the ritual. More importantly, it didn't match the final draft. The memory jumped to the front of her mind. She had ran the numbers once more, wrote it on the note to correct it, and then went to lunch. The memory charm had muddled things just enough for her to forget about it.

After years of working on the Arithmancy when they had finally got it down to the final cluster and she had forgotten to carry the one. She locked eyes with Harry. The last thing he saw was the unrestrained panic in her eyes.

~§~

Everything froze. Slowly, his vision began to tear. The room around him shifted, cracked, and shattered. He stood in a vast expanse of darkness. For an unfathomable amount of time, he simply existed in this void.

One moment he was in endless darkness, the next he stood in a comfortable sitting room. Two chairs were arranged to face one another with a small table in the space between them. A figure was already seated in the one that faced him.

The person was a woman that looked to be in her mid-forties. With a witch, that could mean anywhere from fifty years old to ninety. She looked familiar in a way like he had seen her around many times throughout the day but had never spoke. An accidental shared look in the lobby or a silent ride on an elevator. He wouldn't have given it a second thought on a normal day. This was anything but a normal day.

"Join me." The woman motioned to the empty chain.

Harry did as she asked. The rustle of fabric on leather alerted him that he was dressed. A quick examination revealed he wore a simple two-piece suit.

"I'm sure both of us are more comfortable this way." The woman stated.

"I know you, don't I?" Harry studied her face.

"You could say that." The woman gave him a gentle smile. "We have encountered each other quite a few times through the years."

She stopped speaking and let the silence stretch.

"Death." Harry stated.

She inclined her head.

"The ritual didn't work." Harry sighed.

"I didn’t say that." Death replied. "You returned to me what I had once lost. This was the perfect time to finally sit down and chat."

"So, the ritual worked?" Harry asked.

"I didn't say that." Death flashed a sly grin.

Harry sighed. He rubbed a hand over his face.

"Does this have to do with the Master of Death thing?" He asked.

"Master of Death. Please." Death rolled her eyes. "You are marked by death, claimed by it the moment you united the Hallows. Did you find it odd that you survived so much that should have killed dozens of wizards?"

"I didn't unite the Hallows until my last year at Hogwarts." Harry cocked his head to the side. "How would that protect me?"

"You are the Master of the Hallows." Death explained. "Now and forever. Death stands outside of time, as do my gifts."

Harry tried to let that information sink in.

"What does that mean? The Master of the Hallows?" Harry asked after a moment.

"As it sounds." Death crossed her legs and settled back into the chair. "They will only work to their full potential in your hands. The wand will never hurt you; the ring will not tempt you, and the cloak will not blind you."

"I don't supposed I could take them with me." Harry said.

Death smiled at him.

"That would be too easy." Harry sighed.

Her smile grew.

"What now?" Harry asked.

"Now." Death motioned for him to stand.

He did.

"You carry on until we meet again." Death stated.

The walls and floor disappeared leaving only the two seats and the table. Harry now stood in empty space.

"One gift before you go." Death faded away as she spoke.

A ring appeared on the middle finger of his left hand. He recognized a Lordship Ring when he saw one. This one did not have the Potter or Black family crest. Instead, it displayed the crest for the Peverell House, the Hallows Crest.

Harry shifted his attention from the Lordship ring back to Death. She wasn't there. He once more stood in darkness.

~§~

Freezing wind buffeted his flesh seemingly coming from every angle at the same time. His previous experience with time travel via the Time Turner hadn't been as intense as this. Granted, he was going a lot farther than a couple of hours. There wasn't a return trip either. Everything he had left was gone. The death, destruction, and deteriorating magical world as well as the laughter, love, and lives.

Harry knew that this plan was selfish. It wasn't beyond him that he had placed himself in the role of hero once more. His 'saving people' thing was in full force every step of the way. Not that anyone had ever tried to take the role in his place. Someone had to do something to save everyone. His resolve was bolstered every time he looked in George's haunted eyes, held Teddy, or walked down the half-empty streets of Diagon Alley.

He closed his eyes and focused on his plans while the fabric of reality morphed around him. The summer before Fourth Year. The World Cup. The Tournament. The Return of Voldemort. His knowledge of the future would quickly become useless once he started making changes. He needed to stay out of sight until he could make a big move.

The freezing sensation eased, then finally stopped. Harry found himself standing in the Chamber of Secrets alone. The place looked like it hadn't been touched in years. He glanced to the place where the basilisk corpse had laid only to find it missing. It should still be there. The body had been perfectly preserved due to the magic in the Chamber and the nature of the creature.

Something had gone wrong. He was still alive, which meant it had worked on some level. Harry turned his attention to his body. All the parts were there but he wasn't the same. His arm was still attached and hadn't mystically been replaced with the original hardware. He pressed his hands together then slowly pulled them apart, transfiguring the dust in the air around him into a mirror. The face that stared back at him was his. Only it was younger. He had been a few years short of fifty when they had finalized the ritual. Such complicated magic should never be rushed. Now, he looked like he couldn't have been much older than twenty. Twenty-five at the most. Thankfully, his scar still wasn't as blatant as it had been in his youth. The thin strip of lighter skin could easily be written off as a trick of the light.

He needed to figure out what had gone wrong. The missing basilisk corpse meant that he had arrived before his second year. Harry wasn't going to let a few years change his goals. First, he needed some clothes. Second, he needed to figure out what year it was. Third, he needed to adjust his plan accordingly.

Harry strolled over to the closed tunnel hidden inside the statue of a giant head. He had returned to the Chamber a few times after the War. Once to explore, another to grab enough material to replace his arm, and countless times during the ritual preparation. They had found a living chamber off the main tunnel. Unfortunately, the multiple bookshelves had been plundered sometime before they had arrived. The rooms were under the same strong stasis magic as the rest of the Chamber. It looked like someone had stepped out for lunch and would be back soon rather than gone for hundreds of years. Harry was heading there because there was a wardrobe in the bedroom. Any antiques or artifacts it once held were lost to time. Harry wondered if that was how Riddle afforded being able to travel around after Hogwarts, selling artifacts. Borgin and Burkes was the perfect place to sell, and Riddle had worked there.

§Open§ He hissed.

Stone ground against stone as the mouth opened. He waited until it was completed before he stepped inside. The basilisk hadn't made a sound yet.

§Master?§ A voice called out.

He had to jinx it.

§Not master.§ The voice whispered. §Clutch-mate?§

Harry looked at his right arm. It must have recognized the scent. The sound of something large slithering toward him brought him back to the moment at hand. He looked up to come face to face with a basilisk. Its eyes were wide open, the beautiful swirl of gold stared back at him. The only thing that felt different was a little tingle along his spine. Using the basilisk to replace his missing arm must have made him immune to its gaze. That was a nice surprise.

§You are not master.§ The Basilisk flicked its tongue out again. §You are not clutch-mate.§

§No.§ Harry replied. §My name is Harry. Do you have a name?§

§First master named me Euryale.§ The basilisk replied. §New master called me snake. New master hasn't come back.§

Euryale. Harry gave an appreciative nod. Salazar must have been a fan of mythology.

§Are you going to attack me?§ Harry asked.

§No.§ Euryale sighed.

Over the years he had discovered that most snakes were much more expressive than people thought. They were basically cats in noodle form. Logically, he knew that she should probably kill the creature. Things were going to get bad once Riddle got control of the basilisk again.

§Are you hungry?§ Harry asked.

§Yes. Yes. Yes. Yes.§ Euryale rushed forward.

She was too big to wrap around him in the tunnel. Instead, she knocked him back against the wall. She wasn't as large as when he had faced her the first time, but she still had no problem moving him. He wasn't sure if the difference in size was due to him being a full-grown adult or she grew rapidly once she was woken again. Not to say she was small by any means. She was still as thick as he was tall. The impact had also reminded him that he was nude.

§There might be some acromantula in the forest.§ He muttered.

§What are those?§ Euryale asked.

§Giant spiders.§ He explained.

§That sounds tasty.§ Her tongue flicked out a few times.

§I'll open a passage to the outside.§ Harry slid along to get free. §I just need to get some clothes.§

Euryale followed behind as he made his way toward the living quarters. The door opened smoothly. He had taken a couple of steps into the room before he came to a halt. The bookshelves he had expected to be empty were not. An ornate desk rested in the center of the entry room. It had meticulously stripped the first time he had seen it. Just like the shelves, it wasn't empty.

§Euryale.§ Harry looked over his shoulder at the basilisk. §When was the last time you had a visitor?§

§The master who called me Snake was here some time ago.§ Euryale replied. §He was young when he first found his way here. The last time he came he had aged. He smelled of corruption and rage.§

Measuring time when dealing with Magical Creatures was always a challenge. They could keep track via the moon, but Euryale didn't have that option. At some point, most likely the same time he had stashed the Diadem, he had visited the Chamber. Yet he hadn't taken anything. Harry and Hermione had thought that Riddle had stripped the place. Either he had yet to do so, or it hadn't been him who took everything. Hoarding knowledge sounded like Dumbledore would do. He had lost a lot of the animosity, as well as reverence, he had for the old wizard. With age and distance, he could see some of the logic behind the choices, but there were still so many pitfalls to the plans.

It was similar to his acceptance of Ron's actions through their life. The jealousy and strife that popped up were due to them being young. In the middle of it, Ron leaving during the Horcrux hunt had forever altered their friendship. Now, he could see that they were all just scared kids. Ron even more so. Ginny was at Hogwarts, they had no idea if his family was safe, and they were on a fool's errand. Hermione had sent her parents to Australia and Harry didn't have anyone to lose.

Either way, it was a boon for him.

Harry grabbed some functional robes from the living quarters. They were of amazing quality but a few hundred years out of date. Salazar liked black, which was expected. However, the high collar and prominent shoulder-pads were a surprise. They would work well enough for now.

Euryale led him to the passage that led outside. He opened it.

§Try to stick to the giant spiders.§ Harry stroked her snout. §There are other creatures out there. Be careful.§

§Thank you, Harry.§ She slithered forward but stopped before she got all the way out. §Are you going to visit?§

§I'm going to be very busy for the next couple of years.§ Harry explained. §But I will try to visit.§

Euryale accepted the answer and slid out into the night. He watched her disappear into the Forbidden Forest. It was night, at least he knew that now. Hopefully he could move through the castle without being discovered. He missed his cloak and the Marauders Map already.