AN: Another chapter that could have been longer, but hopefully the fact it comes so close on the heels of the previous one makes up for it, ne? Anyway, this chapter is basically filling in some time before the next load of events takes place. The next one after this should skip over November for the most part, and then pull us into the Christmas stuff, which may take a chapter or two itself. Anyway, please enjoy it! Also, I'm looking for a new beta, anyone interested?

Beta'd by: NIX'S WARDEN

Chapter 19 – Approaching Winter

James Potter was wondering just where and when everything in his life had started going wrong. He was a good man, wasn't he? He had a loving life, two awesome kids, even if his daughter was more than a bit strange, and he just went on living his life like any other normal person would.

So why did he find himself being confined to a single room by his old headmaster?

Dumbledore had managed to smooth over things with the Ravenclaws who had found him in their common room – unconscious and with his clothing partially destroyed thanks to whatever had hit him – but had immediately shut him up in the guest rooms he and his wife were currently living in.

Everything had been as close to perfect as he could want just that past summer. He'd been living a comfortable life, his family was happy and healthy, and no one in the Wizarding World knew where they were. He'd gotten careless then, thinking that no one would even think to look for them in Canada.

Then Amelia bloody Bones had to turn up and ruin everything! He was certain that the thing masquerading as his deceased child had something to do with that, it was simply too much of a coincidence. Now, James knew that sneaking into a student's room wasn't something that could be so easily dismissed, but maybe if he had a reason for doing it things would be okay...

Damn, if only he had his old invisibility cloak, things would be so much easi- Wait, that's it! He'd almost forgotten about it because he'd been trying to sort out whatever alliances he could that his family had, but hadn't Dumbledore said he'd gifted the thing with the family invisibility cloak in its first year?

Yes, if he said he was retrieving a Potter family heirloom, then things could be brushed under the rug. After all, magical Britain loved family things, whether that be bloodline gifts such as metamorphmagus abilities, family magic passed down from parent to child, or enchanted objects with a lot of history attached to them. James vaguely recalled his mother talking to his father about how angry the Smith family was when Hufflepuff's cup had gone missing, especially as they were supposed to be descended from the founder.

He could also claim the cloak back, as it really was a Potter family heirloom, and 'Harry' was no longer a Potter, not after James had removed him from the family. There were so many things James could do with that cloak, and perhaps he could finally gather the evidence he needed to prove that he was right, that 'Harry' was not his son!

xxxxx

On the other side of the world, it was the early hours of the morning. At Mahoutokoro, the Japanese magical school, the dormitories consisted of two buildings, one for males and one for females. There were students who didn't live on site that travelled every morning and afternoon to and from school, but not many.

A handful of these students had recently sent letters to one Harry Ritter, a number of them wishing for a pen pal that could help them with their English, while others were curious about the person himself, the magic used in the West, or something else.

One of those who had sent Harry a letter, A Yuki-Onna named Tsurara Inoue, was lying awake despite the hour. There were several things responsible for her remaining awake at that time. The main thing was how she was considered something of a failure of a Yuki-Onna.

She had almost zero aptitude for ice manipulation. She had more success with lightning than she did ice, and that was something that Yuki-Onna traditionally had trouble with. She excelled with Illusions, probably due to her Yoko grandfather, who had taught her when she was a young girl, and who she had likely inherited the skill from.

Tsurara was also considered somewhat expendable by her more harsh clan members, because she would never have children of her own. A Yuki-Onna's body was cold, and that wasn't a good thing for the eggs in their bodies, and very few of her race could bear children past the age of twenty-five. Tsurara, despite her lack of skill with ice manipulation, had one of the lowest internal body temperatures ever recorded for her race, and her ovaries had failed when she was barely nine years old.

Still, the girl had her pride, and she strived to be the best she could be with what she had. Her scores in school were really high, and while she was only ranked 'fourth' in Illusions in her year, she still managed to beat a number of students who had better natural skill than she did, including several kitsune.

Because of her drive to do her best, and the whispers and rumours from other Yuki-Onna students, Tsurara didn't have many friends. She hadn't really thought this 'Harry Ritter' would be one either, but she was happy for the opportunity to improve her foreign language skills, and so had written to him with that in mind.

The reply letter she received had been polite, but not as distant as she thought it would be, especially as she knew she was one of a number of students who was writing to him. His reply was personalised as well, and he'd attached a list of several western spells he knew that dealt with ice.

A small smile crossed her face as she imagined hitting one of her less pleasant cousins with a 'snowball' spell, or using a frost spell to make one of them slip up. No one would link it to her unless they saw her do it, she was known to be useless with snow and ice after all.

She wondered if Harry – he'd said she could use his first name, as he wasn't quite used to the Japanese convention of referring to someone by their surname – would appreciate some of the notes she'd sent back with her following letter. Apparently he was trying to see how much he could learn about Japanese styles of magic and may possibly transfer over to Mahoutokoro as well. She'd decided to give him a little help there and had copied her notes from her own lessons for him to read through, hopefully they would do some good.

Perhaps... perhaps this Harry may even become a friend. She'd like that.

xxxxx

Tsurara wasn't the only one who'd sent Harry another letter. Others had as well, and each of them was just as individual as each other's. The Oni that enjoyed playing musical instruments had sent along a vial containing memories from several of the times he and his friends had played together. An Ame-Onna had asked him about several magical plants native to Britain that were rather rare elsewhere, and whether he might be able to find her some seeds. A Tengu sent him several photos of Mahoutokoro and asked if Harry could send him some photos of Hogwarts in return.

All these and more were sent to Scotland, to Harry Ritter. When they arrived, Harry would read through each of them and write out a reply just as individual as each letter that was sent to him. As time would pass, the similarities between letters would decrease even further, as Harry became more familiar with each individual he was in contact with.

That's getting ahead of things right now though, what was occurring in the present is much more relevant.

Harry had discussed the potential locations of the remaining horcruxes with his reapers, his familiars, Reinforce, and the Uminari group. Nanoha thought they should just use a Wide Area Search spell to find them, but as was pointed out to her, that wasn't exactly the most discrete method of searching for something.

Goodness knows what the goblins would think or do if they found their tunnels infested with flying pink lights. Harry's opinion was that they would either close the bank until they'd found out what they were, or possibly flip out and declare the next goblin and wizard war.

They'd started wars for less after all.

Nanoha had then gone on to ask how they were supposed to find something if they weren't going to even search? If what Harry said was true, and the goblins didn't care what they stored in their vaults, then they were going to have to do something illegal to get into them.

Unfortunately, she was right. Gringotts was goblin territory, and there laws governed the entire place. They did have treaties and agreements with various wizarding communities, but most of them were written along the lines of 'You can store our gold, but we have access to it, and so neither side will go to war with the other'.

It was actually rather interesting how things were set up. The goblins literally had a monopoly and a stranglehold on the wizarding world's currency, which forced witches and wizards to at least not offend them too badly. The magical humans, on the other hand, were safe in the knowledge that the goblins protected their gold very well.

That was part of the problem though, the goblins guarded the vaults very well. Aside from their habit of hoarding everything they could get their hands on, including old and forgotten magic, they had their own brand of magic as well, just like house elves did, and so no matter what forbidden, ancient, or simply 'unpleasant' magic Harry learned of, he could never be sure that he was prepared for everything he might encounter in the goblin tunnels.

The goblins only advertised a handful of protections available for each vault. There was the standard key locks, there were blood-based ones, password protected ones, and various others that had all sorts of requirements for allowing one entry to the vault, much like the entrance to the Ravenclaw common room asked someone a riddle.

Then there were the doors without such 'simple' locks, like ones which could only be opened by a goblin with the right authorisation. There were even rumours of doors that would suck someone in if they didn't fulfil the requirements, and be sealed into the vault and kept there until they died and rotted away.

Higher level vaults could also be guarded by dangerous creatures, anything up to and including rank five dangerous beasts, such as dragons, chimaera, manticores, and even nundu for the really daring – or suicidal as some would say – and as Gringotts was goblin territory, the same restrictions that the wizarding world had didn't apply there.

Of course, it wasn't the magical creatures that Harry was worried about, and if a regular witch or wizard actually thought about it, they wouldn't be much of a threat to them either. A fourth year could conjure chains, it was only a step up from rope, and animate it to wrap itself around an opponent. Such an 'attack' would easily take care of the physically inclined beasts at least, and there were methods of cancelling out or avoiding other things, such as dragon fire.

Magical enchantments were a concern, as they could be both subtle and lethal at the same time. Nanoha might believe that a Barrier Jacket would protect her from low power spells easily, but that was Mid-Childan and Belkan style magic, which, if Harry was being honest, was rather like hitting someone with a large, blunt hammer.

How would a Barrier Jacket protect one from a conjured poison gas? How would it deal with mental compulsions or something like a dementor's natural abilities? Truthfully, it simply couldn't, and it was what made Harry believe that Terran magic was, if anything, far more dangerous than Mid-Childan and Belkan styles of magic.

They all seemed to forget that, while the material for Harry's golems came from off world, the techniques used to animate and power them were purely Terran. There was a reason, after all, that Harry was not, as he sometimes referred to Nanoha, a 'beam spammer' Bombardment style mage despite his reserves being more than enough to match the others.

No, sometimes subtle and complex beat out raw power, and that was why Harry was being so careful, and dare he say it, respectful of whatever the goblins may have in store for any intruders. He'd been more blasé about the protections on Voldemort's other horcruxes primarily because the memories he'd ripped out of the other horcruxes had told him how they were protected, as well as what magic Voldemort knew and could have implemented at a later date.

He'd proven that a Barrier Jacket was little use against several forms of Terran magic in a spar with Nanoha later. He'd set several traps around the 'battlefield' beforehand – underhanded, yes, but definitely effective – that had completely messed Nanoha up.

It was hard to fight when a rune trap using a sticking charm had kept her from flying into the air, and she wasn't able to move enough to dodge a disarming charm that had ripped Raising Heart out of her hands. A confounding curse had confused her just as easily as it would anyone else, and when she had finally managed to get into the air, she'd been forced to dodge something like fifty bludgers that Harry had made and enchanted beforehand, giving her no real chance to cast any large scale magic at him, which required a charge up time.

She was right when she had said, afterwards, that one Starlight Breaker would have completed destroyed everything and all of his preparations would have been for nothing. However, Harry was also right when he'd told her that it didn't matter how powerful a spell was if she wasn't given the opportunity to cast it or if she was incapacitated before it was cast.

That was also the reason Harry favoured Terran magic and the bracers on his forearms, the casting time was low and he didn't have to stop moving to attack. When he did use Mid-Childan or Belkan magic, he tended towards the quicker spells as well. He would have said lower ranked spells, but Bloody Daggers, a favourite of his, was AAA ranked after all.

Nanoha had pouted after that, and it wasn't only Harry who ignored her muttering about how unfair Terran magic was and how it cheated and didn't play by the rules. Judging by the look in their eyes though, both Fate and Hayate were as amused as he was, though both vocally agreed with how they thought Terran magic was 'cheating' because there wasn't very much it couldn't do.

Harry had responded in a very mature and grown up manner, transfiguring a pile of leaves into an army of stuffed toys that buried the girls in a pile of their small bodies, squeaky little voices declaring their victory over the 'tyrannical' foreigners.

That had been a fun day for Harry. The next, unfortunately, wasn't as pleasant.

That was the day James Potter demanded the invisibility cloak back.

The problem? The invisibility cloak really wasn't 'invisible' any longer.

Harry had, after all, freed the reaper trapped in there.

xxxxx

"What is this?" James growled after he'd thrown the cloak over his shoulders.

"It's the cloak that the headmaster gifted me for Christmas back in first year." Harry replied calmly, his eyes flickering to the man himself.

They were currently in the Headmaster's office, with Harry being backed up by his three familiars – a rarity, as recently Loki and Isis had been intensely focused on sparring with each other and pushing themselves as hard as they could – while James and Lily were both there as well, along with their two children. Dumbledore and an Unspeakable, one Harry hadn't met yet, were the only others there, the former due to it being his office, and the latter to confirm that the cloak was actually a Potter artefact.

"No it isn't!" James snapped. "This thing has absolutely no enchantments on it at all!"

The Unspeakable, using the 'name' Scroll, cast several spells at the cloak.

"The material is over a thousand years old, and there is a great deal of residue on it." He or She, it was impossible to tell, said. "I do not believe that a thirteen year old could find something like this easily, so it likely is the artefact he claims it is."

"Then why isn't it working?" James' eyes flashed with anger as he shouted at the Unspeakable.

Harry wasn't surprised that James was pissed off. The cloak truly was ancient, as the Peverell brothers had died a very long time ago, and no one knew how the Hallows had been made, none aside from Harry that was, and that was only because he was one of the rare few that chose to study Necromancy and survived the experience. It was likely that, if Harry wasn't the only true necromancer currently in the world, then they could probably be counted on one hand, with fingers to spare too.

That was a rather depressing thought when one recalled how unskilled Harry was with Necromancy, not being able to defeat that Revenant rather stung Harry's pride. His skill with magic was great, his versatility and power both high, but limit him to Necromancy only and he could only do a few basic things.

He was glad his reapers were teaching him the handful of things they knew. Without them, and without the two things his shade had been able to impart to him, Harry would have had to literally create techniques and invocations from scratch, and considering that Tiet was the energy of life and death, survival wasn't guaranteed when experimenting with it.

In fact, necromancers had a stupidly high death rate compared to those who studied other disciplines. Becoming a necromancer could be fatal, experimenting with new techniques could easily be fatal, attempting to deal with spirits beyond your ability was almost always fatal, and then there was the persecution necromancers faced due to how their chosen field was often misinterpreted and both hated and feared.

"The cloak stopped working rather recently." Harry sighed. "As it is now, the cloak is exactly that, just a cloak."

The Unspeakable agreed. "Perhaps the cloak needs to be... 'reactivated' in some manner? As it was in Mr. Ritter's possession when he was removed from the Potter family, it is possible the magic rejected him. However, even I cannot tell how the magic of this cloak could be restored. I would suggest you look through the journals of your ancestors, Mr. Potter, perhaps you will find your answer there."

Harry knew they wouldn't. The cloak was a Peverell artefact, and that family had been extinct since the thirteen hundreds. The last Peverell had, in fact, contracted a magical parasite that was also now extinct, and in his zeal to rid himself of it had not only killed himself, but completely and utterly destroyed his own home and everything in it.

Coincidentally, that was also around the same time that Fiendfyre first came up in spell development history books.

"Understood." James said stiffly, before taking the cloak off his shoulders and marching out of the Headmaster's office. Lily, looking concerned for her husband, immediately went after him. The Unspeakable bid everyone farewell, and even shook hands with Dumbledore, Harry, and the Potter children, before leaving through the floo.

Harry, his familiars, Brian, and Rose left the same way James and Lily had, through the door and down the staircase into the castle proper. At the bottom of the winding staircase, beyond the gargoyle, Harry paused as he felt the eyes of the Potter children focus on him.

"Yes?" He asked curiously.

"Was that... really an invisibility cloak?" Brian asked. "It's just, I remember asking for one when I was younger, and I remember dad got me one too, but those things are bloody expensive, and it only last three years before it stopped working properly, and even before that it had a couple tears in it."

Harry chuckled. "And you're wondering about an invisibility cloak that's been passed down parent to child for over a thousand years, yet remains both intact and working? Of course, this same cloak just so happens to 'fail' when its previous owner tries to claim it back."

Loki glanced at the two. "Like the Unspeakable said, the cloak was very old, and the residue left on it is very potent. To have the spells woven into it last as long as they did, it must have taken an immense amount of power to keep it going. So yes, that was an invisibility cloak, but as you saw when your father tried it on, it no longer works as such."

"Do any of you know how to make an awesome cloak like that?" Rose piped up.

Harry huffed out a half-laugh. "Making an invisibility cloak isn't exactly difficult, pretty much anyone can do it. However, there's a massive difference in the quality of cloaks that can be made. I believe that I know how to make a pretty good cloak myself, but I personally prefer concealment spells."

"Why?" Rose asked curiously.

"Because it's easier to move about with a spell on compared to having a blanket thrown over your head." Harry replied. "Why are you asking, do you want an invisibility cloak of your own?"

"I wouldn't mind one." Rose admitted unashamedly. "I don't think I'm good enough to cast the concealment spells either, so if you're offering, then yes, I would love an invisibility cloak."

Harry paused at hearing that, before letting out a laugh. This wasn't a chuckle, but an actual laugh, one that sounded rather pleasant despite the raspy quality his voice still retained. He didn't know why, but Rose's blunt way of speaking amused him to no end.

"Ah, sure, I'll see what I can do for you." Harry told her. "Both of you in fact. I know several different ways cloaks can be made, I'll see if I can either merge them together or make something myself."

Demiguise hair and woven runes, perhaps soaked in a potion or two and imbued with certain properties? Usually, only one method was used, but there was no reason not to mix several of them together, so long as he made sure none of the different methods clashed with each other.

"Thank you." Rose chirped happily.

Brian sighed and rubbed at the bridge of his nose, used to his sister's antics. He glanced down a hallway he was fairly certain his parents had gone done, before looking back at Harry. Brian didn't see what his dad did, he saw a really smart kid who was trying to be more grown up than he was, and at least partially succeeding. He could admit that Harry was a bit scary, but he wasn't a monster.

"Sorry about dad." Brian said to Harry. "He's been really wound up lately, and he's not really thinking straight. If he just calmed down... maybe things would be different, but everything he sees is just bringing up memories and stuff. We've heard more stories about him and his friends in the last month than we have in forever."

"You have no reason to apologise." Harry waved him off. "Honestly, I seriously doubt I and your father will ever be anything but antagonistic towards each other, we're just... perhaps 'too different' will suffice? Regardless, whether I get along with your father or not, I wouldn't mind getting to know the two of you."

"Sure thing!" Rose readily agreed.

"Okay, why not?" Brian also agreed, though less enthusiastically than his sister.

After that, the group stayed together for a few hours, discussing things such as their hobbies, their likes and dislikes, what food they liked, and what skills they had. Brian had taken after his father in that he was pretty damn good at Transfiguration, but he was rather interested in Harry's golem creation, while Rose enjoyed finding either obscure uses for common spells, or common uses for obscure spells. Brian just said she liked to be contradictory.

Harry, in turn, told them off his fondness for both subtle and complex magic. One other thing that he shared with them was that he was working on building up his body's resistance to various poisons and toxins, and when asked why he was doing so, he asked them 'why not?' He didn't mention that he was contemplating using poisons himself, or at least paralytic ones, and that he could only imagine how much more effective his Beelzebub golems would be with such substances imbued into their metal bodies.

Eventually the two groups parted ways, the Potters were going to their common room to do some of their homework, and Harry's group were going to spar a bit more, before focusing on some of their individual projects.

This meant that Loki would be experimenting with various spells that he wanted to alter or combine, and even a few that Hound, the head Unspeakable, had asked him to test out. Isis was reading a few books on healing, and had asked Harry to try and infuse a crystal with Tiet for her to experiment with, her current project was her attempting to develop a spell that would allow limbs to regenerate. Harry's project was simply hurrying his golems along. At the rate things were going, he was becoming rather hopeful that he'd have the seven of them finished in a week or so.

Lindy had said that she wanted to test out how effective his golems were, and that she was going to put them through, with no input or direction from Harry, some of the TSAB's rank exams to see how effective they were, both individually and as a group.

Harry was aware that she would be sending a report to her higher ups, who were no doubt eager to understand Harry's abilities. He was, after all, an unknown to them, and one with his level of power wasn't someone you wanted to remain an unknown. It was the sort of thing that Loki would think up, but it was also not something Harry had a problem with them learning.

How far he'd come with his Necromancy however, that was another matter entirely. The only ones who knew exactly what he could do with Tiet were his familiars and Reinforce. The one who came closest to them after that was Fate, and even she only really knew a few vague things about the Astral Plane and the spirits that resided there, in addition to the fact he had a shade in his service of course.

Harry's amusement tailed off as he channelled a small amount of Tiet to his eyes, allowing him to see the three reapers who were even now following close by him. The three, from what Harry could hear, were talking about old times, fond memories, and other positive things. It was probably an effort to not feel so weak.

The third reaper, the one that had been sealed inside the wand, had had it the worst out of all three of them. He was so weak that Harry had taken to giving him daily infusions of Tiet in order to help him, and had been forced to put his exploration of the Astral Plane on hold too.

Harry wondered if the three reapers would ever see fit to tell him their names. His shade hadn't given him its name, but shades shed their identities like a snake did a skin. Literally, the only way to tell one shade from another was by what they knew; they looked identical, their voices were identical, even their habits were nigh identical.

"I'm thinking too much, I need to cut back." Harry murmured to himself under his breath, massaging his head as he felt a headache coming.

xxxxx

Several weeks passed without any major incidents. Oh, there was a few minor things that popped up, as they did every year at Hogwarts. Some students hexed each other in the corridors when their tempers got away from them, some of the older students set off the wards when they tried to go a bit beyond a kiss with their boyfriends or girlfriends, and the rumour mill was as active as it ever was.

In October, James once again brought up his 'concerns' regarding Harry, and once again he was pretty much ignored, despite the small amount of 'evidence' he'd managed to gather. Really, what he'd managed to cobble together could be considered circumstantial at best.

Still, while it had only been a month since the last time he'd made such claims, it seemed people had been thinking about the possibility. Voldemort was something that everyone in Wizarding Britain had nightmares about, and even a decade after he was gone, only a handful even felt brave enough to speak his pseudonym aloud, and their habits had been passed onto the next generation.

Playing on that fear was a rather devious idea, though he didn't know if James had intended to do that or not, and the longer it went on, the worse things could get. Unfortunately, there was little that Harry could do. He was, after all, only thirteen, and still a student as well.

The only sort of thing that would definitively put him above those accusations would be if he discovered the cure for lycanthropy or something equally immense, and while Harry had poked his nose into the werewolf issue, he had absolutely no idea how one would go about 'curing' such a thing.

Lycanthropy was less of an illness and more of a mutagen transferred via saliva in particular conditions. The light reflecting off the moon's surface acted like an activator for the mutagen when properly focused, transforming them into a werewolf at the full moon. However, the confusing thing was where they turned back into humans afterwards.

Werewolves, it was known, had heightened senses, strength, speed, and even a healing factor. That was also true when the full moon wasn't out, and it was the healing factor which is what allowed them to return to a human form when the mutagen wasn't active.

Of course, despite knowing all of this, Harry couldn't think up a way to reverse the process. Well, he could think of several ways to reverse the mutation and return someone to human form, but the survival rate for such a thing would be a tiny fraction of a single percent, as going too fast would cause damage, and going too slowly would cause organs to become incompatible with the rest of the body part-way through the process.

Harry kept his head down, giving James absolutely nothing to work with. Perhaps if he didn't have anything substantial to take before the Wizengamot, one of them might move to stop James constantly bringing it up, though that was unlikely. Many topics were brought up repeatedly in Wizengamot meetings, some so much that they were almost timetabled into the meeting.

There was usually some complaint or other about non-human magical races, be they centaurs being territorial, a colony of merrow spreading a little beyond the regular limits imposed on them by wizards due to their growing population, boggarts taking up residence in the home of muggle children, or something else.

Of course, talks about muggleborns almost always turned up as well. Harry had to admit that some of their complaints were occasionally legitimate, the Daily Prophet from five years previously had reported on the particularly devout parents of one muggleborn who had fully believed in biblical passage 'thou shalt not suffer a witch to live' and had attempted to blow up Diagon Alley with a bomb when a professor had taken their son there to shop for school supplies.

Of course, such incidents were few and far between, but certain elements of the Wizengamot cherry-picked the worst of cases to support their opinions and proposals. Admittedly, that was a somewhat effective tactic, but also one that was fairly easily countered by someone doing the exact opposite of that.

Still, despite everything that was going on, Harry put some time aside to simply relax every now and then. His letters to Japan were actually helping him here, as he found himself rather enjoying the various discussions he had going with the yokai of Mahoutokoro. Keeping track of so many different letters was also helping him develop his Occlumency further, and increased the number of magic clones he could use by four without undue mental strain.

His golems were complete now, and Lindy had booked them into the ranking exams to coincide with the Christmas holidays. He was putting the Pleiades golems and the Siegfried golems through the tests, as the others weren't really appropriate for them, and they'd start off with a C rank exam and move up to B rank, and if they passed that one too, they'd go onto A rank.

Personally, Harry thought the golems would be able to do the B rank exam, they were well constructed and he had faith in them as well. They worked better if they worked as a group, they were meant to be used together, so he hadn't discounted the possibility that individually they may only register as C rank.

Still, C rank was quite an achievement for a golem by itself, and something that Harry could be happy with. Not that he'd stop trying to improve them of course, he liked to tinker with his creations, improving them were and when he could. It made him wonder if he was trying to impress someone, or if he just had some sort of drive for self-improvement built into his nature or something.

One thing he was still concerned about, however, was NachtWal.

He might have been mistaken when he thought he'd perhaps felt it react to the boggart and amplify his own negative emotions, but them again that might have been exactly what happened, he couldn't be sure, and he was rather reluctant to search out a boggart to test out his theory.

What was NachtWal though? It was the defence program from the Tome of the Night Sky that became corrupted, and leading to it becoming known as the Book of Darkness, but what was it? A mass of broken coding should not react with anything resembling fear. Self preservation, perhaps, but the remains of it in Harry seemed dormant, and it wasn't regenerating at all.

It made Harry rather uncomfortable, but unfortunately, he didn't know what he could do about it.

He would simply have to wait and see, just like anyone else.