Disclaimer: I do not own Katekyo Hitman Reborn! or any of its characters, settings, or dorky, superstitious nerds.

Notes/Warnings: Takes place 5-6 years after the start of the series, and contains spoilers through the end of the Future Arc. Also, it's extremely likely that parts of this fic will be jossed in the very near future, but whatever. Lastly, this story also contains character death, so please be advised.

Indeterminism: Chapter One

God grant me the serenity to accept the things I cannot change;
the courage to change the things I can;
and the wisdom to know the difference.

- Reinhold Niebuhr

The first thing I notice is the look on Gokudera's face. Gokudera has a lot of faces, but usually they're angry, or determined, or confused, or irritated. Once in a long while—more frequently if he's around Tsuna—he'll look happy as well. Those faces are the best, although I like the others too, because they're all part of Gokudera.

But this face… this face doesn't belong on him. He looks completely devastated; shocked, sad, like something horrible just happened. So of course, I ask, "Gokudera? What's wrong?" Because it scares me, to see him look like that. Something's hurt him, and I'm thinking, is he all right? Is Tsuna all right? And I need to know the answer, right now.

But Gokudera doesn't give me answers. Instead, his head jerks up, so fast I almost want to wince, and this time the look that comes over his face is… it's…

But I don't even have time to react to it, because the next thing I know, it's gone, and his expression now is angry. Defensive. Cold.

"Gokudera…" I say, because now I'm not just worried, I'm confused.

"No," he replies. He gives me the cold look a moment longer, then shakes his head, turning his eyes from me. "Go away."

"What is it?" I ask. "What happened?"

And I see his jaw set, his fist clench. But he doesn't turn back, and he doesn't answer me. He doesn't say anything.

"Gokudera," I repeat, more insistent now. "Tell me. We're family, aren't we? Tell me what's wrong." Mentally, I'm running through every option I can think of. Not Tsuna, it can't be Tsuna (please no); he'd have told me right away if Tsuna had been hurt, no matter how devastated he was. He'd be taking charge, in a situation like that, not sitting here in his apartment alone.

…Bianchi, then? Or someone else in his family? He never talks about them, and I've never forgotten what Reborn told us about his mother all those years ago. That could explain his reaction, why he won't answer my question. If it's something personal like that…

That would make sense… but it doesn't explain the funny feeling I now have somewhere in the pit of my stomach. Like I'm missing something, something obvious. It doesn't explain why the fear in my gut is only growing stronger.

"Gokudera—" I try one last time, but once again, I'm not prepared for the way he reacts, the way he turns toward me suddenly, viciously.

"Go away," he hisses in a way that would sound furious if I didn't know him so well, couldn't hear the ever-so-slight edge of desperation underneath. "Leave me alone."

I just stand there, breathing slowly, trying to understand.

Finally his eyes close, and his head drops. And he says, so quietly it's almost a whisper: "You're not real."

I stand there a moment longer. And then, without even thinking about it, I laugh, because I still don't understand, but it's absurd, and laughter is always my response to the absurd. "W… what?"

"Not real," he repeats, and now it sounds more like he's talking to himself. "You're not really here. I'm just in shock." He runs a hand wearily through his hair. "I need to sleep. You need to shut up."

"Gokudera… what do you mean, I'm not really here? I'm talking to you, aren't I?"

He shakes his head again, and starts to get up.

I laugh again, because this is just so weird, and step forward to take his shoulder and gently sit him back down. "Gokudera, seriously, what—"

Then my hand reaches his shoulder, and I stop, and he stops too, and my breath leaves me in a rush.

Because my hand doesn't stop when it touches him, doesn't touch him at all, in fact, but passes right through with no resistance. And it doesn't hurt, but at the same time it feels like I've just been slapped in the face.

And he's staring at me, eyes wide, and I take a step back, feeling like the world's just dropped out from underneath me. On sudden impulse, I reach out to grip the desk beside me, to steady myself. My hand just passes right through, again.

"…What?" I hear myself ask, just barely, and it doesn't even sound like me, it's so unsure. I reach for the desk again, the half-empty mug of coffee sitting there, the chair sitting in front of it; anything. But there's nothing. "What?" I say again, because it's the only word I know all of a sudden. Suddenly, everything is one big, desperate question.

But one look back at Gokudera, and I see I won't find any comfort there.

"…What do you mean, 'what'?" he says at last, his voice shaking a little, but his tone bitter. "You're dead, idiot."

Two things I think of. The first is that 'denial, anger…' five stages of death or grief or something. Because that's how I feel right off the bat. First, 'No, I'm not,' and then angry that he would say it, could even think it. I'm not dead. I can't be dead. I'm right here.

The second thing I think of is Bruce Willis in The Sixth Sense. 'They only see what they want to see.'

And that's when I start to get scared.

I take a couple of deep breaths (do dead people even breathe?). Then I look down at myself, forcing myself to relax, just for a moment. I need to be sure.

I'm dressed in my suit. Jacket open, collar unbuttoned, and tie hanging loose, the way it always is after a particularly long day. I look a bit disheveled, and feel a bit disheveled too, now that I think about it.

But there's no blood anywhere. No wounds that I can see. I will myself to see, force myself to accept the possibility, just for a second. If it's true, I need to see it, I need to be certain.

But there's nothing.

I reach for the coffee mug again, and wince when my hand passes through the same as before. Panic starts to set in, and I fight it; I need to stay calm. I don't feel dead, but…

…Maybe a dream. Maybe this is all a dream.

Gokudera stands up, and I see he's keeping a wary distance from me now. This is wrong, all of it. The way he avoids my gaze, it's like he can't bear the sight of me, like I'm tormenting him just by being here. I feel sick all of a sudden.

"How can I be dead?" I ask him finally.

He doesn't answer, just keeps avoiding my eyes, starting to move toward the door.

Suddenly I feel angry.

"Gokudera, I'm right here," I say sharply, and I experience a moment of satisfaction as he finally does turn back. The feeling dies in the next moment afterward.

"You're in the base, in a lab, covered with a white sheet in a refrigerated room so that your fucking insides won't start to fucking rot before they can do the autopsy."

He's blunt and brutal in a way that only he can be, and only when he's angry beyond all reason. It's not until much later that I realize his anger isn't directed at me, but at himself. As it is, the words—and the mental image they create—stab at me and I'm unable to come up with any sort of response.

Gokudera's silent for a moment, then turns again and stalks down the hall. I just stand there, watching him, desperately wracking my brain for a way to get him to listen. If only Tsuna—

Tsuna.

"What about Tsuna?" I ask, rushing after him. "Let's find Tsuna—he can prove it to you. He can prove that I really am here, I'm not just all in your head."

Gokudera pauses in the doorway to his bedroom, but doesn't turn this time.

"The boss just lost one of his guardians," he says quietly. "The last thing he needs is to start worrying that another one's lost his fucking mind."

He steps into the room without another word and closes the door in my face. A second later, I hear the click of the lock turning. This stops me for only a moment; then I finally start to realize that being a ghost or whatever just might have its advantages.

I take a step forward, and despite everything, grin when I see the edges of the door blur and melt around me. Then I'm in the bedroom, watching as Gokudera collapses on his bed without even bothering to take his tie off.

He does look exhausted.

"Can't get rid of me that easily," I say, but gently, my indignation at having my existence called into question fading. I try to put myself in Gokudera's shoes. Being confronted suddenly by someone I thought was dead. I probably wouldn't know what to think. Especially if I was tired, if I was still reeling from the shock of what had happened.

Maybe it's not a surprise that he'd think he was going crazy. The way he's looking at me right now, it's clear he thinks one of us is, anyway.

"…You're a goddamn hallucination," he says at last, though the fight's gone out of him now, snuffed out by his fatigue. "The only thing you have in common with the real Yamamoto is that you're both fucking obnoxious."

"Just wait. I'll prove it to you. I'll figure out some way."

His eyes are only half-focused on me now, already drifting off. "…And you both never know when the hell to stop talking, either."

I should let him rest. Maybe when he wakes up, I'll stand more of a chance of getting through to him. And it's not like I'm going anywhere for the time being. I think.

"I'll still be here when you wake up," I tell him.

His eyes open again and find mine, briefly. Just for an instant, I catch a flash of genuine regret.

"No, you won't," he says, and closes his eyes.

"…Goodnight, Gokudera."

He doesn't say anything more.

Apparently, ghosts don't sleep.

Or at least I don't. Or I'm not sleepy, at any rate. If I am a ghost, which I like to think is still up for debate.

So after a little while, I start thinking, why don't I just go find Tsuna myself? It'll be faster than waiting to try and convince Gokudera, and at this point, I'm really interested in doing anything that might get results. I don't like sitting still. The fact that I can't touch anything is bad enough. But at least I might still be able to talk to people.

So after a few minutes, I make up my mind and leave the apartment. After pausing to briefly wonder at the fact that I can walk through walls but apparently don't sink through floors (though I'm grateful not to be plummeting through the center of the earth, don't get me wrong), I head down to the lobby and out the door.

And back into Gokudera's apartment.

At first I honestly think I must have taken a wrong turn somewhere. Never mind the fact that I've somehow gone back inside and upstairs. It's still the only thing that makes sense, because the other option is that I tried to leave the building and ended up right back where I started.

So I try again.

After two or three attempts, I finally give up and realize that I'm not going anywhere. Can't go anywhere, more like. For some reason, my ghost body is chained down to Gokudera's apartment. Or more likely, it occurs to me a little while later, to Gokudera himself.

Which means I won't be able to find Tsuna tonight. And even if I did, there's every chance he wouldn't be able to see or hear me after all. Gokudera was right; it's just him.

So then my only chance is to somehow get Gokudera to believe me. And I have to sigh at that, because I already know he won't make it easy.

I ghost back into his room and just watch him for a little while. Well, haunting him, I guess, technically. But mostly just watching and wondering how I'm going to pull this off.

Okay, it has to have been at least a few hours. I don't know what time it was when he fell asleep, but the sun is starting to poke out from behind the distant high-rises now. And I definitely feel like I've been sitting around waiting for a long time. And normally I'm more patient than this, but given the situation, it's understandable, right?

"Gokudera," I say softly. And then a little louder, "Gokudera?"

Nothing. And he's usually a pretty light sleeper, so that's kind of worrying. "Gokudera? Hey, it's morning now." Maybe I should have put a little more thought into how I was going to do this. It would be so easy if I could just shake him a little, nudge him, even.

I lean in close to his face. It's the best I can do under the circumstances. "Gokudera?" I try one last time.

His eyes snap open.

And a second later he's freaking out and jumping back and his hand's going for a gun under his pillow (I always knew he was paranoid, but wow). I put my hands up quickly, apologizing: "Sorry, it's me, it's just me, sorry."

He blinks, lowering the gun he fortunately hasn't had a chance to aim properly yet. "Yamamoto? What the fuck are you doing in my—"

He stops.

Sometimes, when Gokudera gets really startled, it's like everything he's thinking is openly on display. It's like that now. He's scared for a second, and then he blinks a bit more and his hand moves to pinch himself. And after that he looks even more panicked.

"You're not dreaming," I tell him, as calmly as I can. "I told you I'd still be here."

I can see him alternate a bit more between panicking and trying to think things through. I wait. Finally, he gives me a long, considering look, and then darts off to a hall closet.

I watch, increasingly working to bite back a grin, as he shuffles through boxes, finds the one he's looking for, and then starts pushing aside containers of incense and stacks of ofuda to reveal a cache of weird-looking gadgets underneath.

"…What are those?"

"Shut up. Stand still for a sec." He waves one of the devices in front of me and frowns, then picks up another one. I wait patiently as he repeats the process. When he picks up the third gadget, his face turns stern. "Say something."

"What? Um, okay… hi?" I pause, feeling a bit weird. Gokudera frowns again and waves a hand to usher me on, so I continue. "Haha… um, my name is Yamamoto Takeshi. I like baseball. I hope the Yomiuri Giants win this year. Maa… hey, Gokudera, what is that thing, anyway?"

"A digital voice recorder with an electret microphone for picking up electronic voice phenomena generated by entities attempting to communicate in the Infrasound range."

I stare at him blankly.

He sighs. "It records sounds that normal people can't hear. It's used in ghost investigations to communicate with people on the other side."

"Oh." I consider this, then chuckle. "So wait, you keep ghost hunting equipment in your closet?"

He's glaring at me. Oops. "Do you want me to take this seriously or not? You're the one who keeps yammering on about 'I'm really here and I'll prove it,' so put a fucking lid on it."

"Sorry," I say sincerely. He shoots me one last dirty look, and then hits a couple of buttons on the recorder thing. Rewinding it, I guess. He stops it after a few seconds and then plays it back. We both hear Gokudera's voice—"Say something"—and then…

Silence.

And I have no idea what that means, but I'm guessing, not good.

Gokudera turns it up to max volume and plays it once more just to be certain, then scowls. "Nothing." He sighs, then throws the instruments back into the box. "None of this crap is picking up anything out of the ordinary." He looks at me accusingly.

"Well, why do you need a machine to tell you what you can see and hear with your own eyes and ears?" I reason.

"Yeah, that'd be great, if I could trust them." He gives me another look like this is all my fault somehow, then starts to pace around the hall.

"You're not going crazy, Gokudera," I tell him again. I need him to believe this. Come on…

He exhales, giving me another searching look. Then: "Maybe it's an illusion."

It's all I can do to keep from rolling my eyes in sheer frustration. "I'm not…" I pause. Gotta calm down. I think things over carefully, trying to figure out how to prove this, at least. "…Okay, when Chrome and the others do a really good illusion, even the cameras get fooled by them, right? So if I was an illusion, wouldn't one of your machines have picked up something?"

I can tell I've scored a slight victory here, at last; Gokudera frowns and takes on his thinking look once more. He's quiet for a very long moment.

Finally, he looks up. "Do you have any way of proving that you're not just in my head?"

And I can't think of anything to say.

"…All right." He gives me a look of resignation, then sighs. "Maybe we should go talk to the boss."

He takes a step back toward his room… and damn it, it's no good.

I make a sort of "aahh" noise to grab his attention and he pauses, looking back. "I'm not sure that will work either," I confess, hoping to hell this won't just make him give up altogether.

Already it doesn't look good, but he's listening, so I continue, "I kind of tried to go see him last night. The thing is… I couldn't. Once I got past a certain point, I ended up back here. I think—I think I might be… anchored to you, or something. I think maybe you are the only one who can see and hear me."

…Maa, his face; I can pretty much see every word I say driving the nail deeper into the proverbial coffin.

"…So you're not just a ghost, you're a ghost that's haunting me, specifically," he says, looking incredibly dubious.

"Maybe I've just got unfinished business with you or something," I reply, risking a joke.

To my surprise, Gokudera gives me a sharp, almost nakedly fearful look. "Like what?"

I blink—not the reaction I expected. "Um…" Then it's my turn to frown. "Well… I'm not really sure."

"Do you… remember anything? Anything you might have…" He trails off.

No, I realize. I don't even…

"I don't," I tell him, my eyes widening as the weight of that sets in. "I don't remember anything."

"What do you mean, you don't—" he begins.

"I don't remember dying. The last thing I remember, I was in the conference room with you and Tsuna, talking about the Bartolli family and the deal we were trying to work out. Then nothing, up until last night." I don't even remember going to his apartment. Just being there, all of a sudden, and that's weird, really weird, why didn't I notice that before?

He's still frowning, but oddly enough, Gokudera doesn't seem to be as panicked as before. "That meeting with the boss, that was two days ago," he says almost thoughtfully.

"Why would I be missing two days?" I wonder aloud.

"If you… if you really are a ghost…" He still looks a bit unnerved by the idea, but continues on, "…there's different kinds. Residual hauntings, poltergeists…" He wanders to his bookshelf and starts scanning through a row of magazines. "Some of them don't even realize that they're actually dead. They don't remember dying, don't realize how much time has passed…" He glances back at me briefly, then continues searching through the shelf.

"Like Bruce Willis," I say, absentmindedly checking myself for any sign of blood again.

He gives me another long look, but doesn't say anything. Finally, he finds whichever magazine he was looking for and starts flipping through the pages.

"Special Tenth Anniversary Ghost Edition," he mutters, almost to himself. "There's an index… here it is." He falls silent and starts to read. I follow along over his shoulder for a minute, but quickly give it up. Something about trying to look yourself up in an index of the undead supernatural leaves a bad taste in your mouth.

It sucks. Being a ghost.

It doesn't take long for Gokudera to finish the article, but then he is a genius, after all. Afterward, he sits there for a bit, seemingly lost in thought. Then he finally looks back up at me.

"Find me in there?" I ask, sounding less casual than I was aiming for.

He shifts his gaze away from mine. "Classic post-mortem apparition. Usually recently deceased; can sometimes communicate with the living; a lot of times, don't seem to realize that they've died when they do communicate."

My stomach feels like I've swallowed rocks. After a moment, I manage to nod.

"Only, most of those apparitions can be detected using one or more of the instruments I tried," he goes on. "And you weren't."

I stare back at him uncertainly. Is he trying to say I'm unclassifiable… or that there's a possibility that I might not…?

He's staring back, and for once I can't read him. "…There's one more type that might fit," he says at last. "Out-of-body apparition. There's a story in here about a guy who drowned and was pronounced dead. He was lying there in the morgue for more than a day, not breathing. His ghost appeared to his family to tell them he was still alive. They went down to the morgue, asked them to bring his body out, and he recovered."

For a moment neither of us says anything.

"How long have I been dead?" I ask him.

There's a careful, measured look on his face. "About fourteen hours."

"Did I drown?" I say, trying not to hold out too much hope.

He shakes his head, looking away from me again. "…Bled out."

I can't remember the last time I felt this anxious about something. But then again, I can't remember the last time I had this much to potentially lose.

"…We can check," I say at last.

There's a long pause, and then he looks back at me, and he nods.

"We can check."

There are only a few people inhabiting the base when we get there—or to be exact, when he gets there with me tagging along (at least I managed to make it out of the building this time). And I guess the morgue isn't really the first place people want to go in the morning, because the lab is empty when we arrive down there.

Gokudera waits for the security scanner to clear him, then walks in. He heads straight for the back of the room, where a row of long metal tables is visible through another doorway. He shivers a little as he enters, and I'm guessing the air must still be refrigerated like he said.

Then again, it could just be that one of the tables is very noticeably occupied by a tall, prone form covered in a long white sheet.

Suddenly I feel cold as well.

Gokudera glances back toward me, looking much less certain now that we're actually here. "Ready?" he asks me, and I'm not, but I nod anyway.

He pulls the sheet away from my face.

And I see myself.

And I don't—I try not to recoil, but… but…

I don't know what I was expecting. Sometimes people say that dead people only look like they're sleeping. Like they're at peace.

But I look dead. Stark white (and shit am I naked under the rest of that sheet I think I am), waxen, rigid. And I sure as hell don't look at peace.

I sure as hell don't feel at peace.

He must have known, Gokudera. Must have known that there was no possible way, no way at all, so why did he even bother…?

Because I didn't believe it.

It's true. I didn't. Not fully, not quite.

Not until now.

I duck back out into the main lab, then come to a stop, breathing hard.

So stupid. I've been trying so hard to figure out the wrong thing. 'How do I prove to Gokudera that I'm alive?' When really all along it should have been more like… I don't even know. 'Why am I here?' or 'How do I move on or whatever it is I'm supposed to do?'

Denial really is the first stage.

Gokudera finally steps out into the lab behind me, and I don't look at him, but wipe away quickly at the corners of my eyes.

"Sorry," he says quietly. His eyes are a bit red too, but he doesn't say anything more. I'm glad.

Okay. So I really am dead. That's how it is, and I can't change things. I take a deep breath.

"…So what now?" I say at last.

He just shakes his head. Doesn't know either.

"Do you still think you're crazy?" I ask him, only half-jokingly.

"Don't know." He looks back at me, and I can see he's truly at a loss.

Great.

"…Either way, I guess the next thing is to figure out exactly why you're here," he says hesitantly.

Part of me doesn't even care anymore. But the rest of me… well, the rest of me has never been good at giving up.

"How did I die?" I ask him finally. I figure that's at least a place to start.

Gokudera suddenly seems to find the floor interesting. "You were shot," he says shortly.

Somehow I get the feeling there's something he's not telling me.

But before I can ask, his brow creases. "Maybe it wasn't supposed to happen. Maybe that's why you're still here. Maybe I'm supposed to do something to save you."

"…What?" I say in total confusion. Because I'm only just starting to come to terms with the idea that I really am dead, and now he's talking about it like it's something that can be changed. Even though he was the one who convinced me in the first place.

"Why not?" he says, and even though I have no idea where they're going, I can see the wheels turn as he continues, picking up steam. "Haven't we already changed the timeline once to stop people from dying? Why not again?"

Time travel.

He's right.

But… "That was the future, though. The past… that's different, isn't it? Doesn't that make paradoxes and stuff?"

"Maybe. Maybe not." For the second time that day, he starts to pace; encouraged in spite of myself, I follow him. Then walk right through him as he stops.

He doesn't even seem to notice, lost in thought. "What we really need is an expert on parallel universes and time travel," he ponders aloud.

There's a pause. Then our eyes meet, and I know we're both thinking the exact same thing.

"It might be dangerous," I say, feeling a need to be the voice of caution since he's the only one of us who still has a life to risk, after all.

"Yeah," he replies. He turns to look back at the room where my body is, then seems to make up his mind. "…But fuck it."

To be continued…