A/N: Well, people voted for Death Note and I've been wanting to write something Mello x Matt for a while, although there won't be much romance until later on. The title, Kriminalist, is German for 'detective', so that should give you some indication of what this is about. I thought I'd try my hand at first person narration, so that's the format it will take. I hope you enjoy it, since I've not tried this before - but you've always got to keep stretching your boundaries :) Also, as you've probably come to expect with me, this is a little AU. Imagine that Matt and Mello didn't die, and that Near caught Kira before anyone else got killed. Now that Near is undeniably the new L, how will things change for Matt and Mello? It starts during the investigation, for scene-setting purposes, but later on they will be solving their own cases. M for language, mostly. That Mello does have a bit of a dirty mouth.

Chapter One - A Lesson in Case-Solving

MELLO

I was standing outside the apartment in Japan when it hit me. It was stupid. I was going up against Near, on my own, and he had the whole investigation team to help him. Well, screw that, I thought. Time to even up the odds a bit.

Near's clever, yeah, I'll give him that, but I'm clever too, and when it comes to computers we both know a genius. Matt. Near's never going to ask him for help, because he thinks he's God's gift, he thinks he's the number one L successor. That's his mistake. Going it alone, when he could have someone by his side who is capable of hacking any computer or coming up with a strategy for any battle situation, usually whilst simultaneously catching Mew. Plus he's a friend, I kinda missed him this whole time, but I'll never admit that if you ask me again. Even if it is a little weird that you never see his eyes, you know, because of the goggles. He's like some kind of mystery man. He probably only wears them because of that kid in Digimon, Tai something. Whatever. That's not my area of expertise.

So I flip open my cell and call him, just like that. Why bother finding a secure line or anything private? I don't care if Near knows. In fact, I want Near to know. I want him to hear the first stage of his failure, and then when I become the new L he'll look back and say, shit. I could have had Matt on MY side.

It rings twice before it connects. That's quick, two rings. Something tells me maybe he was expecting a call.

"Hello?"

"Yeah, hi, Matt. It's Mello."

"I know. Caller ID and all that."

"Yeah. Whatever. Get your ass over here."

"… To Japan?"

"Yeah. Problem with that?"

"No, it's just… airline tickets?"

"Booked by the time you get to the airport. You can pick them up at the desk."

"How soon do you want me there?"

"Yesterday. Don't fuss around packing like an old woman, just get the essentials and get over here."

"Alright. But, Mells, what -"

"What nothing. See you when your plane lands."

I put the phone down then, knowing he'll do what I told him to do, because it's Matt. He's younger and he likes me and he's not as cocky as Near. Yeah, he's good, but he knows his limitations. He's third in line, always has been, but me and Near are right up there at the top, battling it out. Could-be-number-one and will-always-be-third is quite a distance, and Matt knows it. He's not one to play games, heh, or should I say he's not one to mess around; playing games is exactly what he does, and he's fucking good at it. That's why I need him. Because with Near, everything is just like a big old life-sized game.

Booking the tickets and everything takes about thirty seconds, and now I have a long wait, so there's only one thing to do. Back to work. Snapping off a chunk of chocolate, I crunch on it in a kind of satisfied way, heading back into the apartment to look at my files. Usual anti-Near routine: check for bugs, check for cameras, check for anything moved or missing. Nothing. Good. Down to business.

I look at the investigation team profiles again. L always suspected Light Yagami and I'm not one to contradict the man when he's at work. The fact he died anyway probably just adds proof, because it must have got irritating after a while, being told you're Kira. Even if you weren't, it might make you want to be him. Might make you want to beat L's head in with a shovel, but that's not what happened, is it? He had a heart attack, which tells me in no unclear terms that Light plus Yagami equals Kira. I still don't have any evidence, though, and Near doesn't either, or he'd have done something by now. This Light guy is a real smooth character, he's got it all figured out. Well, I'll just have to figure it out better.

I've run out of chocolate, not exactly the world's most surprising event. Anyway, so I get up and go over to my stash, and the thing is, right, it's right in front of a mirror. So I can't help but catch sight of my own gorgeous self, only not so gorgeous any more, since I've got this scar now. Damn Kira. Stealing my looks, making me ugly like that (not if I stand sideways, though, that way's still good.). And what I realise right then is that Matt doesn't know I'm all scarred up like this. I mean, he literally has no idea. If I could have trusted a hospital I might have been able to make it a bit smaller, but it would still be there, so what can I do?

Why does it bother me, anyway? I can still get by with my honeyed words, and it's not like Matt really pays attention to how I look. Of course he doesn't. He's just a gamer. If anything he's more likely to compare me to Paine because of all the leather, and he knows it pisses me off to be called a girl, but that's the full extent of it. He doesn't care if I have a scar or not, who am I kidding that it matters at all? Ahh, whatever. I'm done with dwelling on this. When I catch that Kira bastard I'll make him pay, because that explosion fucking hurt.

It takes a while, but about twenty chocolate bars later (that's the only way I can count time these days) I decide it's time to go. I've had no new leads, but then I rarely do. That's why I need Matt. I need the edge. I throw on more leather than usual and a helmet, shove another inside the compartment under the seat on my bike, and take off. If Matt's sensible at all he brought his own leathers, and if not he's an idiot, because I'm not the kind of person to just take a car. I mean, I have a car, but I'm a biker, through and through. Matt knows me well enough by now.

I get to the airport in perfect time; how could it be anything less. Matt steps off the plane just as I make it to the crowd of people waiting around with boards proclaiming the names of the people they're waiting for. I came prepared, myself. I've got my very own paper name board ready to greet him. I tucked it into the helmet I put under the seat. I can't wait til he sees it. Heh. It's going to be great.

MATT

Oh, Jesus, I'm bored. For the last bit of the journey they made me turn my gameboy off. It's not fair. I was just about to finish Wario 3 for about the tenth time. The number's not the point, it's finding every single trick there is, and this time I nearly managed to do it in under three hours. I would have finished it, too. The stewardess came over and tapped me on the shoulder, all 'I'm sorry, sir' and 'can you please turn it off'. They wouldn't let me smoke, either. What's a man supposed to do?

I got off the plane fully ready to give Mello all hell for that, but of course in the back of my mind I knew that wouldn't happen. Mello's not the kind of person you give all hell to, he's the kind of person you get all hell from. He's like the final boss, only you're not the hero, you're just an underling. Makes me wonder why I'm going, actually. He abandoned me in England and scuttled off to Japan to work on this case, didn't email or call, not even so much as an IM, and now he's suddenly decided he wants me there…

Well, I always go where he calls. It's my job or something. I always have, probably always will, that's just the way it goes. So long as I get to play my games, smoke, and mess around with some computers, it's fine. I don't think L ever intended me to be a major player. I'm here as tech support, for whoever needs me, and right now it seems like it's Mells who needs me. I'm glad. I prefer him over Near, that kid's a little freaky, right? Mello is a bit too, but at least he doesn't play with those stupid toys any more. And Near shows off all the time. And Near doesn't know my real name.

Yeah, looking at it that way, I'm definitely in Team Mello.

I was just walking through into the… what would you call it? Lobby? Well, anyway, the bit where everyone meets people. I was hoping Mello would be there, since we didn't actually arrange where he'd be, but no need to worry. There he was, standing proud in full neck-to-toe leather, smirking and holding a card that said "Mr Dumbass".

Yeah. Hilarious, Mells. Absolutely hilarious.

A/N: So, there we have it, part A of A Lesson in Case-Solving. As far as I have planned there will be six lessons. I wanted them all to be a chapter each, but it looks like most will be too long for that - I hate drowning people in massive walls of text, and I don't have the time for 10,000+ words a week anyway, so they will be split down into smaller parts. Hopefully on a weekly update, or quicker.

Anyway, please review and let me know what you think so far!