A/N: I actually had this chapter complete on tumblr for a while, but I didn't get around to posting it here. Sorry.

Also the first part does not reflect the tone of the chapter. At all. But it get's pretty dark so there had to be some cheerfulness to balance it out... a bit.

But hey, here's what you've all been waiting for: the first appearance of the flame zombies!

After leaving Spanner and Irie back at the remnants of the Melone Base and meeting up with the rest of their friends they returned to the Vongola base in remarkably higher spirits.

It even held on through explaining the whole situation here in the future to Onii-san.

At least the first time.

But he got it now. He had just summarised it back at them.

Finally after five hours...

But he looked confused as hell again when Hine entered the room they were in.

"Oh, did I leave out the children's art supplies? I must've overlooked it when I was cleaning up earlier. Sorry about that, I do tend to try to keep the base tidy despite the kids' dislike for cleaning up after themselves." Hine commented pleasantly as she picked up the spiral sketchbook from the table between Tsuna and three of his Guardians.

Tsuna couldn't help but giggle when he heard that. And a quick glance to either side confirmed that both Yamamoto and Gokudera were not faring any better. He had to agree that Onii-san would probably not become an artist. Unless he went for something like the style Picasso's most famous pieces were in...

Onii-san looked confused but not offended, as he probably didn't realise she meant his drawings with her comment despite watching Hine flip through the pages of the sketchbook he had drawn into during their explanation of the situation here in the future.

More and more confusion dawned on her face the longer she flipped through it.

"Huh? I thought both I-Pin and Lambo were better at drawing people. Usually I can tell who they are trying to depict..."

That was all it took for Tsuna to bust out laughing.

Nii-san however still looked confused. He just looked back and forth between Hine and the boys across the table from him a couple of times before shouting, "I EXTREMELY don't know you!" He declared as always loudly, "I'm Sasagawa Ryohei!"

Tsuna almost face palmed. Trust Onii-san to forget the person who actually bandaged his scraped fists over at the Melone base.

Hine however just smiled at him.

"I know, I'm friends with your future self. I'm Hine Ayumi. It's nice to meet you... again?"

Of course something had to happen while they were on a break from fighting the Millefiore. Basil had joined them safely enough despite the scare he gave them when he arrived. However the trouble found them when they were sat at their old desks in Nami Middle. Hine had agreed to accompany them and was lounging against the teacher's desk.

Tsuna worried about Yamamoto a bit, because he was uncharacteristically subdued after visiting his home with Hine. Tsuna hadn't gone with them, he'd gone with Haru to make sure she was alright. But when they met up again Yamamoto had worn a fake bright smile that made Tsuna want to cringe.

At least until Hine whacked him upside the head and told him, "don't, Takeshi. I'm sure he's glad to be reunited with your mother once more. Remember what he's passed on to you."

Then she continued dressing him down about the most ridiculous things, like the fact he was apparently wearing two different socks and hadn't eaten the leaks in his miso that morning, until he started whining at her.

But he also forwent the fake smile.

Tsuna did wonder how close Yamamoto was to Hine in the future. It was rather hard to imagine, because they didn't know her yet in their time. But even though Yamamoto was changed with his past self, she seemed to connect to him to some degree. Despite the fact she still cringed at most of their reactions to her, if she thought they weren't looking.

Yamamoto's smile was still tinged with a small amount of sadness as he sat at the desk he was assigned in their class but he did chuckle when Haru burst into the classroom with I-Pin and Lambo. Both of which had ran up to Hine and were chattering faster than comprehensible in their excitement.

Hine had been smiling gently at their antics as she leaned against the teacher's desk, giving the small children the illusion of having her full attention, when the next moment her head whipped towards the windows and her face set in a worried frown.

Tsuna strained his ears.

Did she hear something they didn't?

"We need to leave. Now." she barked with a seriousness that surprised them coming from the otherwise so easy-going teen. Even more surprising to Tsuna however was the fact neither I-Pin nor Lambo got scared by the sudden change in demeanor and obeyed without a single complaint. That didn't extend to Tsuna and his Guardians though.

"Hie?" Tsuna shrieked in surprise.

"Who do you think you are to order Juudaime around, woman?!" Gokudera bristled.

Worry still strongly present on her face, Hine turned to Gokudera and sneered.

"We need to leave. Don't argue. I'll listen to whatever you want to argue about later, when we're back in the safety of the underground base. Now, you'll just have to trust me about this. We need to move."

"Already? We only just got here. I haven't even gotten to do any practice swings on the baseball field!" Yamamoto whined half-heartedly. Tsuna was glad he seemed to trust the blond enough to treat her with such familiarity, but he couldn't help but feel it being misplaced in this setting.

Hine sighed.

"Yes, Takeshi, now. We need to detour to the roof already and you practice in the training rooms every day." She instructed with a tone of finality that left no room to argue.

Tsuna realised instantly that Gokudera would continue to argue and Yamamoto probably wouldn't move quickly enough for Hine if he didn't move first. And with the urgency only very thinly veiled in Hine's voice Tsuna didn't need his hyper intuition to tell him he needed to move and needed to do so now.

"Well we've done what we wanted to do now, so if Hine-san believes we should leave, we probably should. We'll get to go to school again more than we want to once we're back in the past after all. Let's go, guys." He agreed and moved to the door where Hine was waiting. The others followed him, even if Gokudera was giving Hine the stink eye. She accepted that easily enough as she herded their group to the roof. Tsuna had wondered why exactly they needed to go via the roof but he got his answer a moment later.

"Hibari-kun, we have to leave."

"Hn."

"This is not up for debate."

"..."

Tsuna just watched her in amazement. Was she suicidal?!

Another sigh left her lips as Hibari refused to even acknowledge her any longer.

"Well if you don't believe me, look into the school yard."

Of course that caught all of their attention. And just as naturally all of them looked down through the fence and saw a group of people standing just inside of the school gate. They looked normal enough. Their hair colours were a bit funky though and their faces reminded Tsuna of what Hibari looked like when he was out for blood. Not the expression exactly… But maybe the feeling? He couldn't put his finger on it, but their presence was definitely rubbing him the wrong way despite not knowing why exactly.

At least he didn't until they finished looking around in confusion and suddenly started to attack each other.

Shocked to say the least, their group from the past watched with morbid fascination as suddenly the ones fighting in the school yard lit up with multicoloured flames and started strangling, choking and biting each other. Their flames intermingled and entwined until some of the colours were extinguished and some of the people dropped to the ground where they lay lifelessly. Only Hibari didn't look appalled at the scene. In fact he looked intrigued and about to jump in to join the fray. If not for Hine holding him back by the collar of his shirt, he probably would have.

"This, ladies and gentlemen," She explained in a carefully controlled voice, "is what our Tsuna and the others like to refer to as 'flame zombies'. If you encounter one, run for it. For any more information you'll have to ask Bianchi."

Tsuna nodded mutely. He didn't trust his voice at the moment as his eyes were stuck to the horrid scene below as the 'flame zombies' had started to draw blood and only became more vicious for it.

"Come on, we have to get out of here, before they notice us." Hine muttered gently pulling them away from the fence and pushing them towards the door again. She kept her grip to the back of Hibari's shirt and lead the way to the cellar where she then opened a hidden panel in the wall to reveal a secret door with the pulling of a lever.

"Welcome to the foundation headquarters." She said obviously trying to lift the tension a bit, "Our Hibari-san's life's work. Also know as the Namimori Disciplinary Committee, which is the reason it's connected to Nami Middle apparently."

Hibari gave a short but acknowledging grunt while still being pulled by the back of his shirt like a petulant child (his arms crossed in front of his chest as well). The rest of their small group except for Tsuna, who had seen it the last time around with future-Hibari, looked around in amazement.

"It's connected to the main base, but you need special access grant to enter it." Hine continued to explain as she lead them back through several corridors to their main base.

Surprised at that little bit of information Tsuna looked at the blond teen.

"And Hibari-san gave it to you?"

Hine just giggled.

"No, I asked Kusakabe-san for it, in case of an emergency. And since my case is quite well known in our group he granted me access."

Bianchi found herself confronted with a group of rather anxious middle schoolers (sans her little brother) after their trip to the town. She looked rather resigned as if she knew exactly what they had seen despite not having joined them. She probably did.

She sighed and buried her face in one hand.

"I'm probably not the best person to ask about those." She muttered mostly to herself. In the anticipating silence currently reigning however they could hear her words quite clearly.

"Should we ask someone else?" Tsuna asked hesitantly.

Again she sighed.

"No, there are only two people who would be able to give you a full account. One of which is currently unconscious in the infirmary and the other is too close to the subject of the matter. She refuses to talk about it. So I'll have to do it."

Then she turned around abruptly and started walking down the hallway. However when none of the middle schoolers made any move to follow her, she turned back and merely raised a single eyebrow.

"Are you coming? You're not expecting me to explain out here in the hallway, are you? We're going to the briefing room. Do me a favour and grab everyone who needs to know. I'm not going to repeat myself."

"Ayumi-nee-chan! Quick!" Lambo urged as he pulled the blond teen along by her hand. Ayumi obliged as the boy was so upset that he was tripping over his own feet trying to get her to help with whatever it was. He hadn't even told her what he was so upset about. Knowing Lambo however it was something about someone he cared very dearly about, because if it had only been him wanting attention he would have just outright demanded it rather than become all flustered about it.

The five-year-old finally let go of her hand once they entered the room the girls and younger children were sharing.

"Ayumi-nee-chan has to fix Haru-nee-chan and Kyoko-nee-chan! They got home and they cried like they have ouchies, but Lambo-sama couldn't find any ouchies!" The exuberantly worried five-year-old exclaimed.

Ayumi frowned worriedly as she laid her eyes upon the huddled together sobbing forms of the two girls. Deliberating her next course of action for a moment, she watched the two inconsolable girls before she sighed and joined the two girls on the bed. Gently, as not to startle them she placed a hand on each of their shoulders.

"I understand." She whispered sadly. Just as gently she lifted their chins so she could look straight into their tear stricken faces.

"I know, it is hard to comprehend what you have seen this afternoon. And I fully agree with you that there are few things more horrible than what you have witnessed." She told them calmly.

Uncertainty glistened in their eyes as they internally debated whether it would be better to try to forget what they had seen or accept the knowledge the world wasn't safe because there were people or things like flame zombies out there.

Again Ayumi sighed before she pulled them in for a hug. She laid their heads on her shoulders and continued talking to them on soft soothing tones.

"It is easier to avert your eyes from the truth. It is so very easy to live life like a happy dream where no one needs to struggle and no one is in need. But our world does not work like that... There is more than just a light side to a coin. For every person there comes a time when they are confronted with the dark side of our world. Some people get to only see some of the lighter parts of the darkness, some spend their whole lives immersed in a mixture of both. Some like you are introduced the worst way possible by confrontation with one of the darkest aspects there is. But you mustn't forget, there is always a reason for the dark as there is always a reason for the light."

Ayumi paused there and just let her words sink in. She only resumed when she felt both of them nodding against her shoulders.

"There are people out there who do not wish to be honest. They harm others by manipulating them and by stealing from them. Some even murder and kill other people. Flame Zombies are not the way they are by choice and they weren't born that way either. They did not come to be naturally. They used to be normal people like you and me, who were noticed by the wrong people. People without morals who selfishly take other people's freedom to fulfil their own ambitions. They manipulated their bodies until they were in such pain that they broke apart. By all means they were killed when they were forced to become like that. No longer capable of coherent thought, only trying to soothe the agony."

Pulling back in shock the two teens looked at Ayumi with wide eyes.

"That's horrible!" Kyoko cried out.

"Who would do such things?!" Haru added.

Ayumi smiled gently but sadly at the two of them. At least they could still feel compassion despite witnessing such a horrible scene.

"People without respect for the worth of a human life, Haru-chan. It takes so much pain to bring a single life into this world. Yet they do not appreciate what they were given, they feel they need more. And I agree, Kyoko-chan, it is truly horrible to have to live like that, if you can still call their existence a life. Always in pain, always yearning for relief, yet unable to understand just what they want and therefore resulting to violence like a toddler who doesn't know how to get what they want. Don't you think to them death is mercy? That the short moment of pain when they die is so much more preferable than the endless days, weeks, months and years of agony? Don't you think, if they could choose, they would choose to rest eternally?"

The two girls looked rather conflicted by the implications but seemed to give the question some honest thought.

In the meanwhile Ayumi got up from the bed and stretched her legs to get back the feeling in them as she got up. Then she turned back to them and asked, "don't you think people who play with other people's lives without regard to their worth should be stopped? Even if it means they have to die?"

Bianchi was already waiting in the briefing room when they finally rounded up all of Tsuna's conscious, teenaged Guardians and Basil.

By some stroke of luck... No, actually the mere mention of flame zombies had already been enough to pique Hibari's interest, so he followed them at a distance he was comfortable at.

And seeing the large group move with a purpose, Reborn had attached himself to Tsuna's shoulder.

Thankfully Bianchi was already wearing her goggles to obscure her face, so Gokudera did not keel over the moment he entered the room. But she was impatiently drumming her fingers on the table as she eyed each of them critically. She didn't even acknowledge Reborn's presence with more than a short nod. If that didn't speak of the gravity of the matter, then nothing did.

"Is that all of you?" She asked tersely, "if not, I'll leave it to you to relay the information to whoever is missing now, because I'm starting now. Take a seat. You'll need it. The following is not feeble minded."

Tsuna gulped but did as he was told as the wall behind Bianchi now showed a projection of what seemed to be the official CEDEF report due to the large CEDEF logo displayed and mirrored on the screens in front of them. That might explain why she was not the best to ask when it came to that topic. She had obviously only read the report not compiled it. Yet she would still know way more than their group from the past, so at least a basic instruction was sorely needed. Especially since she seemed to be very unnerved by the concept of these flame zombies.

Tsuna's Guardians followed suit, none of them in the mood to aggravate the already tense woman. After witnessing what those… were they still people or should he rather classify them as wild beasts?... things?... did, all of them knew, whatever information they were going to be given, they would most likely not like it.

"You asked about the flame zombies," she opened her explanation, "and since most of you looked like you'd seen a ghost when you returned, I take it you came across one of them."

Reborn tilted his fedora to shadow his eyes on Tsuna's shoulder. The young Mafia boss to be could tell the Hitman was intrigued but he remained silent. Perhaps he hadn't been aware of the flame zombies?

Nobody said a thing, so Tsuna spoke up, "not only one, but a whole group of them. They … fought each other."

Everyone noticed his obvious stumble when expressing what the flame zombies had been doing, but his friends seemed to feel similarly about it. With the exception of Hibari, who seemed indifferent.

Bianchi nodded and switched to the second slide of the report.

"Taking the members of your group in consideration, that makes sense. But we'll get to that later. The entity 'flame zombie' first came to the attention of the Vongola about four years ago when there was a series of incidents involving a single flame zombie each. They were killed in the end, but at the cost of several casualties. Not all of them caused directly by the flame zombie involved, but the original had infected fighters they had managed to engage in close combat. That's why someone had the bright idea to call them flame zombies. Unfortunately it stook despite sounding absolutely ridiculous. The official scientific term is 'broken'. Hardly anyone uses it though."

Bianchi sighed. Tsuna however fought the urge to facepalm. Was that name really so ridiculous when the Mafia fought using flames and box animals? The official term was hardly better. But was that really worth a mention when those things were downright scary?!

"However four years ago was only the point when the Vongola Alliance became aware of them. The northern provinces' famiglia had incidents involving them as far as 7 years back," Bianchi amended showing them a map of the iconic boot that was Italy and its surrounding countries.
"Apparently it ties in with the destruction of a small research facility inside the Swiss border, called Laboratorio Esterno in the official documentation commercial register of the canton Ticino, that had been razed down by an unknown group of flame actives."
Bianchi paused there looking decidedly green as if she was struggling with what she was to say next.
It was Reborn who interrupted the silence before she could overcome whatever was hindering her.
"Who did it?"
The answer to that question seemed way more palatable for Bianchi, or perhaps she just didn't want to disappoint Reborn, because she didn't lose a beat answering, "the investigation was inconclusive. The only thing the investigation could fathom was it was done with all seven flames of the sky and the perpetrators had to have had quite a grudge against the research staff. The corpses were burned beyond recognition and none of the research could be salvaged."
Reborn frowned.
"Including the sky flame? It could only have been a famiglia.", Gokudera supplied equally grim.

Bianchi mirrored his expression with a nod.
"It would seem so, if not for the fact nobody claimed the kill. If a famiglia had been involved they would have laid claim to it no matter how shallow the reason for doing it, simply because of the boost in recognition it would give them for having enough flame users to manage such a feat."
Reborn gave a short nod in acquiescence before continuing, "who conducted the investigation?"
The slide behind Bianchi changed to depict another map with an area marked red, a word in Romaji which was most likely a name and a coat of arms.
"As the facility was only just inside what you'll recognise as Ex-Estraneo territory, the family who took over their territory after their fall: the Pesca famiglia."
Reborn snorted.
"So we can forget about the accuracy of the investigation. The Pesca wouldn't find any reliable evidence even if it were to jump straight at them."
A small mocking smile blossomed on Bianchi's face but disappeared a moment later when a annoyed sneer took its place.
"Not to mention they never shared their report with the rest of Cosa Nostra, not even their allies, despite the very real threat of the infection spreading. The Vongola alliance had to hack into their database. Not that that was very hard, they might as well have just given it to us. But the fact remains the infection was able to become this bad is because they didn't share their information. As soon as the origin of the flame zombies was clear, CEDEF conducted their own investigation, but that was three years after the destruction. By that point the reliability of the evidence had already drastically declined. There was however still flame traces to be found. Only enough to prove that all flame types were involved, but their remaining presence in itself speaks for very powerful flames for there to still be lingering traces years later."
Tsuna paled. He didn't like the direction this was going.
"Was it connected to the Mafia?", he voiced hesitantly, "the research facility, I mean."
Reborn looked at him with approval for thinking to ask about that. (Right after looking decidedly murderous for daring to ask what amounted to a very stupid question, before he amended what he'd really meant.)

Bianchi motioned to the next slide of the report projected behind her.
"I was getting to that: as I said before, none of the research could be salvaged. We can only assume what they were researching there. Any and all documents were disintegrated through liberal usage of storm flames. No chance of reconstruction. Most of the room designations were scorched too. Whoever did this was thorough. The CEDEF was however able to reconstruct some writing that seemed to come from one of the larger rooms of the facility by scanning the wall fragments for paint components. What it spelt out however did not bode well."

Again Bianchi changed slides to show a black and white image full of little red computer generated squares creating barely legible letters.

"Vero Estraneo…" Gokudera hissed incredulously.

Tsuna whipped his head around in shock. His eyes met Gokudera's whose face had lost most of it's already pale colouring as well. They remembered that name well.

"Exactly. All Evidence points to the Laboratorio Esterno belonging to a branch of the destroyed Estraneo famiglia."

Tsuna's knuckles turned white with how hard he gripped at the briefing room table.

"The ones who conducted human experiments and were obliterated by Mukuro and the Kokuyo gang when they left?" He asked to make completely sure.

"The very same," Bianchi confirmed.

Tsuna grit his teeth.

"Does this mean the flame zombies are most likely a product of failed human experimentation?"

None of the teens in the room looked particularly happy about this. Even Reborn shadowed his eyes completely.

Bianchi sighed.

"Most likely. There is however no concrete proof for that claim. All possible witnesses seem to be… broken or dead. But the full image would support your theory."

Again the slide on their screens and behind Bianchi changed.

"It translates to: 'even the stars will not limit us. For we are the true Estraneo,'" she explained in a clipped tone, "knowing what the Estraneo had been up to before their demise, this sounds very much like a declaration to do much worse."

Tsuna clenched his fist so hard he could feel his blunt fingernails drawing blood from his palm. He just couldn't understand people who did things like that. Of course there would be people like Mukuro if there as people who insisted on creating them! But instead of getting those, they imprisoned the one who struck back.

"Back to the hard facts," Bianchi resumed, "an individual is broken by severely fracturing a their dying will flame."

"Aneki, that does not make any sense." Gokudera interjected gruffly, "you can't fracture a flame."

Bianchi just lifted a single eyebrow in silent challenge.

"That's what we thought up until four years ago. While it might be true for a normal flame, it is possible to fracture and break dying will flames."

The image onscreen changed, now showing the outline of a human with an orange flame inside it.

"Dying will flames are created inside your body as a manifestation of your will. There is a pseudo-organ which generates and stores these flames. Decreasing the stored flames in this pseudo-organ will tire you out, emptying it will outright kill you. Scientists call this pseudo-organ 'core'. There has been some experiments to find a reliable way to determine the extent of a person's core, but a solution has yet to be found. A 'flame zombie' is created when the core of a person is set under enough stress to crack it. If not treated a crack will turn into a break, resulting in a 'flame zombie' whose core constantly leaks flame into their body creating a lack of flame in the core."

While Bianchi was explaining the image on their screens showed what she was describing. First the flame shrinking, then disappearing and the outline of the human disappearing as well and finally a flame with a crack which evolved into a break that split the flame in two causing the flame to leak into the whole outline.

"Now, a 'flame zombie' loses all coherent thought. They are driven only by the pain they are in from constantly leaking their flame and want to alleviate this pain. They will act on instinct alone. Unfortunately their instinct is to stop the leak by stuffing it with strong flames. Statistics show that flame zombies will most likely go after a person with the same flame as they have-…"

Confused Tsuna interrupted, "then why do they go after Hine that much?"

Unimpressed Bianchi finished her sentence, "flame zombies will most likely go after a person with the same flame a they have or Hine Ayumi. Although if both are viable options, they will most certainly seek out Ayumi. The prefered order of victims is: Ayumi, strong flame of the same type, strong flame of another type, weak flame of the same type, weak flame of any other type and flame inactive. If there was any semblance of intelligence in the masses of zombies chasing Ayumi, we'd assume there was someone targeting her specifically, but there isn't. So we're at odds when it comes to why she is their main target."

Tsuna bit his lip. That last fact didn't help alleviate his guilt for berating her after Kyoko disappeared at all. She must've had to evade some flame zombies at that time...

Again the slide changed, this time showing a stupidly accurate image of what Tsuna had imagined a flame zombie to look like before today: a comic image of a grey half-rotten corpse on fire.

"If you encounter a flame zombie by all means try to evade it by a large margin. They are usually not exactly intelligent. The alliance has trained operatives around taking care of the infestation to reduce the risk of flame zombies going after civilians. They will deal with the rampant flame zombie. If you can't evade and are forced to engage, keep it at a distance and kill it as fast as possible.", Bianchi explained before she was once again interrupted by her brother.

"You said usually."

Bianchi smiled wryly.

"Well caught, Hayato. Yes, I said usually. Once a flame zombie has consumed a considerable amount of flames the body will be sufficiently saturated so the core has a base-level of flames needed for coherent thought. When that point is reached the flame zombie will regain a semblance of personality. The most accurate description of this personality would however be a vicious psychopath. If you encounter one, you might as well curse your rotten luck, because they are incredibly rare. They are also exponentially more dangerous than the normal kind. The flames flooding their bodies enhance a normal flame zombie's senses and their strength, but in combination with coherent thought only the most experienced fighters come out such a fight without cracking or outright breaking. "

Tsuna chewed his bottom lip. Didn't that just sound peachy? But there was another issue he was concerned about.

"You said a flame zombie used to be a normal person. Is there no way to restore their cores? Do we have to kill them?"

Bianchi frowned in understanding.

"There is no other way known to neutralise them. Many Mafia-affiliated doctors have been broken trying to find a cure for flame zombies, so ultimately the Vongola-Alliance has banned it. They're to be either evaded or put down."

She regarded all of them with hard, unrelenting eyes.

"That's why it is so important for you not to let a flame zombie get close to you. A reliable way to treat cracks has yet be found and if you break, everything's over."

With both flame zombies and the Millefiore, how much worse could their future get?

Uncertainly Tsuna looked at his Guardians, all of them wore grim expressions.

Except for Onii-san, who chose that moment to break his uncharacteristic silence up until now and explain aforementioned silence.

"I EXTREMELY DON'T GET IT!"

The rest of them just groaned.

On a little side note, I really had to incude the first scene, because I read Bleach before KHR and they always go on about Rukia's abysmal drawing skills. And then I saw Ryohei's... and there's a motivational poster somewhere in the depts of the internet about it. And as I already pointed out, I really needed something lightherated because this chapter is rather depressing otherwise.

As always I'd appreciate if you dropped a comment. And thank you to all of you who've followed the story!

For any of you who feel inclined, hit my tumbler where I post some fanart, including illustrations for this story, and I have my ask open if you're confused about anything or want to discuss my headcanons or any other part of the plot.

And also it was KHR week the week before last, so looking around tumblr is a treat anyway.