AN: And now for a oneshot that turned out to be uh, really long. Another good thousand words and it'd be about the same length as a regular chapter update of one of my multi-chapter fics, whoops! Anyways, this is an idea I've sort of been wanting to play with ever since I started writing Phantasmal Black, and it (probably almost definitely) falls underneath the realm of AU. I'm actually really pleased with this oneshot so I hope everyone enjoys it as uh, potentially soul-crushing it might be at times.

That's all for now! Thanks for reading!

Black Echo

(AU)

Summary: He knew that sooner or later, one of them was going to catch up with him- and he could only hope that it would be Kudo.

In reality, he knew it was only a matter of time before someone caught up to him. This wasn't a situation that could continue forever.

He had thought many times about bringing it to an end himself, in one form or fashion. Most of them involved properly discussing the matter with the one who had become his friend before he even realized it, the famed detective of the east, who had been forced to disappear from the spotlight in order to protect his own life- and more importantly, the lives of those around him. Sometimes he worried that Kudo Shinichi didn't value his own life as much as he should, but it was exactly that kind of selfless nature that had impressed him in the first place.

Were he any different, the situation might have already ended long ago, and he'd have been the one to do it. Kudo Shinichi would have truly vanished from this world, his actions against the mysterious group known only to him as the Black Organization cut short before he could even truly raise a hand against them.

Instead, he'd lived, to strike several decisive blows against them, counterattacking them every time they thought they had backed him into a corner, all while not revealing the truth of his existence to them. It was incredible, really. Even as the boy gained more and more allies, he never stopped thinking five, ten steps ahead, prepared for any possible scenario that could be thrown at him, and throwing together plans in the blink of an eye for the ones that had managed to escaped him.

As clever as he was, he wasn't omnipotent.

He'd never once doubted him from the start, after all.

It was a bit hilarious, really, considering that the first time he'd met him, he'd brought along with him what he had thought at the time was a clear warning sign of his true nature. It was ironic, really. Never in a million years would he have suspected that the very liqueur his codename had been taken from would have been the key to begin unlocking the mystery behind the mysterious poison the boy had been fed on that fateful night that caused him to disappear, forced to live a lie, hiding from the world, pretending to be nothing more than a slightly smart first grade student by the name of Edogawa Conan.

Kazuha would have surely said that it was a sign. Heiji still viewed it as lucky coincidence.

He'd thought many times of bringing this whole farce to an end. Of speaking up, of saying something, of revealing his betrayal to his friend. But each time, he missed his chance. And each time, it got harder and harder to say anything, as the two of them grew closer and closer. He wasn't exactly sure when it was that they had become such close friends, but it had happened before either of them was even aware of it. From that point on, there was nothing that could be done to stop it.

And as Edogawa Conan- no, Kudo Shinichi, got deeper and deeper into the mystery of those clad in black, as he gained more and more allies, and the stakes became higher and higher, it became nigh impossible to tell him the truth. Too much time had passed, he'd become too close to him. What would it do to him at this point? He'd never questioned his loyalty from the start, not even in the millions of scenarios that he played out in his head, planning out strategies well in advance to counteract each one.

Out of all the scenarios that he considered, the fact that Hattori Heiji might be a member of the Organization was not one of them. It had never been one of them. In fact he was pretty certain that Kudo would be offended on his behalf if someone so much as tried to tell him the truth. Like it was a bad joke.

It wasn't by choice, not really. If he could go back now and change the past, he would have accepted the consequences of what would have followed had that incident not been erased. It wasn't like he could blame his past self though. His reaction to what had happened, and everything that followed, was still understandable to him even now.

It had happened back in late middle school, when he'd started gaining a reputation for himself as a detective, when he started getting attention from the media. He'd reveled in it then, an excited grin on his face, happy that he was starting to be doing something he'd always dreamed of doing. He'd never admit to it, but it was his father who had inspired him to become a detective in the first place- he had admired him quite a deal when he was a child, and wanted to become someone like him. And now, case by case, he was living that very dream, developing a reputation for himself as a brilliant young detective.

So when he'd learned that he bore no blood relation to his father at all, nor to his mother, he'd naturally been shocked. What kind of people he did bear blood relation to was what had nearly destroyed him. There were cracks, forming, all around him, threatening to shatter the world that he'd built for himself, to destroy everything. In the back of his mind, he was well aware that this was probably blackmail, watching as the pretty reporter twice his age almost gloated about the documents that she had in her hands, all the proof that she needed to release a rather scandalous story, the kind of thing the media would have eaten up, the kind of thing he'd never be able to escape from.

One that would not only surely destroy his own dream- but might take his father down with it. His father, who he admired, even if he never said that much, never spoke such words aloud, who had taken in the orphaned son of murderers out of a sense of pity and duty, who had taken him in because his wife was still distressed after losing her fourth child, who was almost catatonic with despair after the doctors told her that her life could be on the line if she attempted to have another. His father, who had brought him into his own home, and raised him as his own child, and never once questioned the sort of person he'd grow up to be, in spite of knowing his origins far better than he did himself.

It had been an accident, really.

In all of her gloating, she never noticed that she'd taken a wrong step. When she lost her footing, he'd even tried to help her, to keep her from falling- but he didn't react fast enough, didn't reach out his hand quick enough. Her head broke open on the bottom step, painting the area around where she fell a vivid red. It was an instant death, nothing could have been done about it, nothing could have saved her.

It had been an accident.

But with those papers in her bag, he already knew that the world wouldn't view it as one. He should have done the right thing back then- but hell, what kind of fifteen year old was going to be thinking straight after the news he'd gotten? Certainly not him, given how overly prone to emotion and impulsive action he still was to this day. Kudo might have been able to do the right thing, steadfast and prepared for anything that might have happened afterwards.

But fifteen year old Hattori Heiji? Not a chance.

It wasn't until he was already home that he realized he'd taken her papers and her recording device with him. He'd been in a daze, really, not that that was much of an excuse. Really, none of it was an excuse for anything. What his reasons were really didn't matter- it didn't matter that the Organization had found out about the incident, it didn't matter that they had used that information to blackmail him, it didn't matter that they eventually came to whisper threats of what would happen to those around him if he tried to leave them, their gazes fixed on the one person that Heiji knew that he could never stand to lose.

None of that mattered anymore, none of that changed anything.

Talent, prospect, and location. Those were the three key reasons that they had their eyes on him in the first place. If they begun at a young enough age, he'd become a splendid member before he knew it.

And he really had.

By the time he crossed paths with the one known as Kudo Shinichi, he already felt that this fate was something that he couldn't escape from. By that time, he'd already been given a codename, had already sunk himself deeply into that Organization. The smiling face of Hattori Heiji was slowly becoming something of a mask, his real nature straying further and further away from that of who he had been. He'd done too much, said too much, knew too many things. Slowly, bit by bit, piece by piece, he really was becoming the one they had come to call Paikaru.

It wasn't all bad, really. Not everything that they used him for was horrible, as loathe he was to admit it. He was talented with languages, as it turned out, and there was usually very little that was objectionable about serving as a translator. He purposefully began to study more and more languages for that reason, before he knew it becoming fluent in any number of languages, so many that he nearly lost count at times. It came naturally to him- he was a proper polyglot, really, and they used him for that with great zeal.

The other reason behind his pursuit of language was, of course, so that if the day ever came, he could disappear to almost anywhere in the world. As much as he saw no exit for himself now, that didn't prevent him from planning ahead, thinking up ways to vanish, to go where they couldn't reach. Their organization was international, but it wasn't omnipresent- there were any number of third world countries he could vanish into if he needed to, so long as he could speak the language.

Should that day ever come, the worst possible scenario would have already played out. Heiji could only hope that it would never happen.

But when it was bad, it was bad. Even worse was the fact that he was becoming increasingly numb to it all. Even after meeting Kudo, even after changing for the better, there was still a certain sense of numbness that lingered, an indifference which only managed to heighten is guilt.

His reputation as a high school detective and his connections to his father made him the perfect candidate to help root out and chase down traitors within the Organization, be they members, or those who the Organization had blackmailed. He was the perfect person to get close to those people- and the perfect person to betray them. On good days, all he had to do was lure them somewhere, and his job ended there.

On bad days? The Organization had taught him any number of skills, skills which he had on more than a few occasions, put to use.

Given that he'd been sent on a mission to investigate Kudo Shinichi, and to determine if he had really died, he honestly didn't know why he hadn't said anything when the supposedly dead high school detective himself had suddenly shown up at the crime scene. He'd jokingly wondered if it were perhaps love at first sight, but given the way he'd been so awed by him, the way that he had been so entirely against Heiji's expectations, maybe that wasn't so far off after all.

Whatever the case, he said nothing at the time, biting his tongue and burying the truth from those who asked. He'd seen nothing, he'd heard nothing. As far as he knew, Kudo Shinichi was still dead, given the way he'd all but disappeared after giving his deduction, almost like a ghost. There was still a mystery there, still a hint of something that needed to be solved- and so Heiji continued to chase the scent, as much for himself as for the Organization now.

He was curious.

It was that scent that drew him to the meeting of Holmes fans, and although he was disappointed to not find Kudo there as he expected, he nevertheless did find some familiar faces- the Mouri family and their young, curious ward. A ward that became more and more curious after a murder happened before his very eyes, as the investigation proceeded and he began to notice him more and more, seeing in him an echo of the one he'd been sent to track down.

"Yer Kudo, aren't ya?"

Edogawa Conan and Kudo Shinichi were one and the same.

This was the very answer that he had been sent to find, and though it was one that sounded absurd on his lips, it was the truth. And yet, even so, he still didn't say anything, pretending he'd seen nothing, he'd heard nothing, he knew nothing.

It probably wasn't until he met him next that he began to understand why. Being a detective had once been his childhood dream, but even though he'd been gaining praise right and left for his deductive abilities, that dream had lost it's luster. There was no spark, no passion behind it. No joy at having correctly identified a culprit, nothing. The Organization wanted him to polish his skills, seeing great promise in that area one day, and with that knowledge weighing on his mind, the appeal of chasing a mystery had slowly begun to wane.

Kudo Shinichi was the spark that brought it all back, lighting up his world in a way that it hadn't been for a long time. He hadn't even realized how deeply he was drowning in black until he came into his life, slowly bringing color back into it. Suddenly, there was excitement again- working together with him to solve the mystery at that mansion had unlocked something within his heart, something that he thought long buried.

And he was more grateful for it than Kudo would ever know.

And yet, at the same time, it made everything all the harder.

"Hattori- have you... have you ever killed someone?"

There was no way he could ever tell him the answer to the question that had managed to catch him so off guard was yes.

Kudo would tell him about it later- what had prompted him to ask that question, how he was still haunted by what had happened on Tsukikage Island. How he couldn't save the culprit, couldn't prevent them from committing suicide, letting their body be consumed in flames, heading on to join the rest of their long departed family. How he cursed his tiny body, how he was certain that he could have done more had he realized sooner, had he not gotten so caught up in his deduction.

How he couldn't prevent a woman named Miyano Akemi from being killed by the Organization. How he had gotten there too late.

He hadn't noticed the way that Heiji had swallowed at the mention of it. He'd already heard about that incident himself. Something about the woman wanting to free her sister from them- a girl scientist not much older than he was by the name of Sherry. He'd never met her, but he knew her reputation- and he knew full well that she was the one who had developed the poison that had caused him to shrink in the first place.

Poison that he happened to have himself. Poison that he couldn't think of a way to give to Kudo without revealing everything. Poison that he wanted to hand over to him, poison that he fantasized that would make Kudo forgive him for everything if he gave it to him, but knew that he wouldn't.

Heiji never thought he'd be able to become the kind of person who would take a bullet in order to keep someone from killing themselves. Maybe it was Kudo who changed him, or maybe that had been in him all along, and he'd just managed to forget it as he slowly became someone he wasn't. In that ambulance, as those gathered worried that he wouldn't survive, he almost wondered what he'd done to deserve any of that.

Of course, none of them knew. None of them knew who he was, what he'd done.

Especially not Kazuha. Never Kazuha. He never wanted her to know what type of person he'd become, how he'd strayed so far away from the bright world where she lived and thrived. How he wasn't certain if he could ever quite make it back there. He tried to push her away sometimes, but she would always push back, invading his life like she never had any intention of leaving it, no matter what he said to her.

Maybe it was good for him. Whenever he thought he was at risk of falling too far, she was there for him, holding out her hand, a bright smile on her face. Before he had met Kudo, she had been Hattori Heiji's only lifeline, bringing him out even when he was certain that the smiling teenager had ceased to exist. She'd probably saved him more times than she realized, and not just because of her lucky charm, which sometimes felt like a lead weight around his neck whenever she hung it there, fussing about him having left it behind again.

When he realized he was in love with her, he had sworn considerably in every language that he knew- a rather impressive litany, all told. Of all the things that he hadn't planned for, developing romantic feelings for anyone- much less his childhood friend, who he treasured so much already- was right up there on the top of the list. He was so convinced that he didn't have that in him, that he didn't even notice his own feelings for her until it was far too late. They'd already taken root.

"What the hell are ya doin' to my Kazuha!?"

As if he had any right to say something like that.

Because even as Hattori Heiji continued to assist Kudo Shinichi whenever he asked for it, Paikaru still continued to work for the Black Organization, always holding his silence, but never objecting to any of the missions that they handed to him. He didn't have that privilege, acting against their interest as he was. If he hesitated, they'd know.

On one occasion it had lead him to come to meet Kudo, the smiling mask of Paikaru firmly in place, wearing it so well that the shrunken detective couldn't even tell. He wasn't certain how he felt about that.

Go investigate the mysterious woman who has started snooping around, they'd said. An English teacher by the name of Jodie Saintemillion, who apparently taught at Ran's school. Go and confirm if she's really with the FBI like we suspect she is. It wasn't as if it was his intention to approach Kudo with this mission in mind, the Professor had merely just happened to call around then. But the fact still remained that he'd taken the chance provided him without a second thought, effortlessly acting as both friend and foe without anyone noticing.

He really was a better liar than people gave him credit for. Being a wonderful liar while acting as a terrible one was a piece of Paikaru's mask he could never fully take off.

"Isn't there one? A strange, foreign woman around you."

The suggestion had slipped naturally out of his lips. The best method of approaching the woman involved using the fact that he was one of Edogawa Conan's friends to his advantage, to get close to her without her so much as suspecting a thing. She would never second guess one of 'Cool Kid's' friends, and she never had.

He'd used Kudo. He felt awful about it, sure, but even so, he hadn't thought twice about it. Heiji wondered sometimes if he would have done it differently today, and then decided not to dwell on it, afraid of what the answer might be.

Guilt had already become a familiar friend to him at that point. Everything would have been so easy for Kudo if he could just be honest with him and confess that he knew far more about the Black Organization than he had been letting on- of course he did, he was one of them. One of those same people that he despised, one of the ones who had torn him away from his normal life, had forced him into hiding, had changed everything.

Maybe it wasn't hopeless, though. He'd seen the way that he treated that Haibara girl, that girl that he knew had once been Sherry. Of course he knew who she was- searching for traitors was part of what he did. More than anything else, it was what he was most known for in the Organization. Paikaru was one of the codenames those who betrayed the Organization feared the most, though most of them had no idea that he hadn't even so much as graduated high school yet. Suffice to say he knew everything about her, it wasn't hard to recognize her face, just ten years younger, given what he already knew Apotoxin could do.

Maybe he wouldn't hate him after all if he knew the truth, wouldn't cast him out as a traitor. Maybe he'd even try to help him.

But the difference between him and Sherry was the fact that Sherry hadn't been working for the Organization all along. She'd run away from them, betrayed them outright, and that was why that old man Gin was looking for her with such fervor. As much as she blamed herself for creating that poison, she had no blood on her hands, much as she seemed to be convinced otherwise. She wasn't the one running around and using it, after all.

When he'd first met her, Heiji almost felt his heart skip a beat, feeling as if this surely would be the end of everything. And yet, strangely enough, she didn't react to him at all, didn't even so much as bat an eye at him. Like Kudo, she never once questioned him, never once suspected that he might have any connection to the people she was trying to run away from.

He probably had Kudo to thank for that.

Acting as Paikaru had become all to easy for him over time. It was something that was ceasing to be a mask, one he wore to survive, and starting to become his real face. Meeting Kudo changed all of that, turning Paikaru once more back into a mask, one that he could still slip on effortlessly, but one that he didn't wear easily any longer. If it was Kazuha who kept him grounded throughout all those years, it was Kudo who helped turn him back into the person he once was, before any of this had begun.

And if that brought with it an overwhelming sense of guilt and a deep sense of regret for everything that he had done, a burden that he would have to live with for the rest of his life, then that was fine. For the first time in a long time, he found himself wanting to truly just be Hattori Heiji again, the high school detective of the west, Kudo Shinichi's rival and best friend. He wanted nothing more than to cast aside the still necessary mask of Paikaru, to fully embrace the hotblooded, sometimes reckless, often impulsive detective that had earned him so much criticism from the likes of his fellow high school detectives.

"I guess they call such a person an 'unqualified detective'."

It was that case that really helped him come to understand just how much he'd changed. It was true that he was an unqualified detective, but it was hardly his hotblooded nature that marked him as such. If anything, that was an improvement- he'd taken it to heart more than Kudo had realized, when he quietly spoke words of support for him. He didn't deserve them, honestly, but it still made him happy to know that his friend really did value his skills as a detective.

They couldn't know. They could never know. He'd drag this secret to his grave if he could.

Sometimes he'd forget that he carried that mask at all. But it would never last that long. There was always something that reminded him.

Truthfully, he thought his death sentence would come after that night on the haunted ship. He'd been half tempted to tell Kudo that he couldn't help him, but he knew that after coming this far with him, he couldn't abandon him like that. His friend needed him, and damn it, if there was something that he could do to help him, then consequences be damned, he would. Whatever happened after that would happen, he thought, making as many arrangements in secret as he could, before he arrived in Beika.

The mask he wore that night was a very literal one indeed, for a night allowing him to become none other than the one he'd come to value so deeply, the one he wanted to protect even as he lied to him.

He probably never would have gotten through the aftermath without Vermouth, ironically enough. Not only did she know about Kudo, it seemed as if she had long since known about him- and for whatever reason, she found it amusing, and had decided to say nothing. So when he had lied and told Vodka that he had decided to impersonate Kudo Shinichi in hopes of drawing out information about him, hoping to learn if he was truly dead, Vermouth had been the one to happily supply that she had been the one who had instructed him to do so. There was a look in her eyes that he knew, one that told him that she owed him a considerable favor now, and that she one day expected it to be paid in full.

She held her tongue, and he held his.

There were still whispers after that, of course, but they had been settled when Paikaru carried out his next mission without hesitation. After the quite literal mask he'd worn on that ship, he slipped on the metaphorical mask once more, shifting from hot to cool. There was a man who they believed was at risk of betraying them to the police. He'd holed himself up at a certain hotel, and wouldn't come out for anyone, waiting for a contact that he had in Interpol to arrive.

When they both finally came out of the hotel, Paikaru had been waiting. It was finished within two shots, before anyone knew what had happened. He'd spent two days stacking out the hotel, and it had been over in an instant. Packing his bag, concealing the rifle within a guitar case, he'd effortlessly slipped back into the crowd, blending amongst everyone long before they had been able to figure out where the sniper had shot from. Even as a familiar pair of Tokyo MPD officers hurried past him, he slipped by them without them even so much as recognizing Hattori Heiji underneath Paikaru's mask.

This too, was something the Organization had taught him.

"He'll be scary in the future."

Kazuha's father had said that in regards to his deductive abilities, but if he had never ended up crossing paths with Kudo, that very much well might have been true in a way that the man saying them never would have expected. In a few more years, he might have completely lost himself to the Organization, and it would be Hattori Heiji that would become the mask, not Paikaru. It terrified him to think about now.

When Kudo stopped contacting him about the Black Organization, Heiji feared the worst. That he had realized his secret without him having to say anything, had finally learned the truth that he had been hiding from him all this time. But when he suddenly called him out of the blue one day to talk about a mysterious female detective who had appeared with questions about Kudo Shinichi on her lips, he breathed something of a sigh of relief.

The guilt only managed to grow, especially once he realized that the reason Kudo had suddenly started keeping him out of affairs dealing with the Organization wasn't because he didn't trust him, but because he had come to value him so much that he didn't want to put him at risk. He'd become someone so important to Kudo, that he'd become someone that he wanted to protect, to keep safe from their reach. It was touching, moving- and it also made him feel like the worst person alive.

Because he still couldn't bring himself to say anything. At this point, it was already impossible. His overbearing sense of guilt, and his fear of destroying his friendship with this person who had changed him for the better, who had dragged him out that black abyss, sealed his lips.

Any illusions that he might have about Kudo forgiving him were long gone now. Too much time had already passed, too many things had gone unsaid.

He wondered how much trouble Kudo might have avoided if he'd just told him everything that he knew. He already knew who Bourbon was, it was part of why he'd been trying very hard to avoid crossing paths with the young man named Amuro Tooru- they'd already met, in entirely different circumstances, using entirely different names. If he crossed paths with him as Hattori Heiji, and he came to learn that he'd been aiding those chasing the ravens all this time, he knew that it wouldn't end well.

He admittedly hadn't known that Bourbon was a mole, working for the secret police. Although he refused to involve Heiji while he was still looking into the matter, he did tell him a number of things afterwards- though he'd skipped over the identity of the mysterious young man living in his real house. Heiji was able to guess who he was anyways, judging from the intelligence he'd gotten from the Organization itself. They'd never crossed paths while he was undercover in the Organization, thank god, Heiji had still been a novice without a codename then- but he'd more than heard of him.

FBI investigator, Akai Shuichi. What Gin would have given for that kind of information. This too, would be something that Heiji would take to his grave, alongside the location of Sherry, and alongside the true identity of Edogawa Conan. Hell, he'd take Bourbon's true identity with him to the grave as well, and he honestly wasn't even quite sure if he even liked the guy. He'd definitely use it to blackmail him into silence if it ever came to that, though.

There was always a sense of worry that manifested in him every time he visited Kudo. Even as he joked with him, even as he worked to solve cases with him, even as they interacted as best friend and rivals, he always wondered when the day was that he'd hear his own codename roll off of his lips. That he had caught a whisper, a rumor, of an Organization member by that name who worked out of Osaka. One who hunted traitors, one who was fluent in more languages than he could count on both hands, one who was regarded as a budding detective.

One that he wanted Heiji's help in catching.

What would he tell him then? The truth?

"Ya already caught 'im long ago, Kudo, he's right here. It's me."

No, he couldn't say that. If anything, he'd work against him, trying to keep him from finding out for as long as possible. It might be a fruitless effort- whenever Kudo finally managed to drag the Organization down, the truth would probably emerge in the fallout. Disappearing might not be a bad idea after that.

The bad thing about having become a better person was that he was certain that nobody would forgive him for the things that he had done, because he sure as hell didn't. And he wasn't certain if he could handle that. There was still plenty of good stuff in the world he could do to try and balance it out, maybe it wouldn't be a bad idea to disappear once the Organization fell, once the truth came out, trying to pick up his life somewhere else, becoming someone else once more.

Most of all he didn't want to see the looks in their eyes when they realized the truth. Not Kudo, not Kazuha, not his mother, and certainly not his father.

What face would be the easiest to give them when they did? Would the answer change depending on who he was dealing with? Hattori Heiji's, racked with guilt, full of apologies but no excuses- excuses were meaningless when weighed against the things he'd done. Or the mask of Paikaru, the liar, the one who could wear a smile even as everything went to hell around him, could act like this had all been part of one long con to ensure his own survival as everything fell apart.

Provided he even had a choice, that is. It was his second worst fear- crossing paths with Kudo when he was working as Paikaru, in a situation that he couldn't explain himself out of. He hadn't noticed anything the one time they'd met when he was wearing the metaphorical mask- but he'd also been Paikaru acting as Hattori Heiji at the time. Should a situation arise where they crossed paths as detective and Black Organization member, Heiji knew full well there would be nothing he could do to stop Kudo from realizing the truth- and he'd have to watch him do it.

But even that would be better than what would happen if the Organization learned the truth. He wasn't so much worried about his own life- he knew the ins and outs of how they hunted traitors like the back of his hand, it was part of his job after all. Disappearing would be a simple matter. Rather, it was the lives of those he would leave behind- he could only hope that vanishing into the ether would be enough to cause the Organization to leave them be.

One day, someone would catch up to him.

And honestly, Heiji prayed that it would be Kudo.