Belated Happy Birthday, BlueUtopiah! *does a little dance*

SPS-kun: Thank you for your review! I didn't really read the manga so I'm just working off the anime/tv series, so this is pretty much my little own backstory to Kurama and Hiei. It works off my earlier fic, The Art of Losing a Fox.

Disclaimer: I don't own YYH

The Fundamentals of Us Part 2

"Her name is Yukina."

The memory of his voice, when he said her name, inspired chills. Not because of fright, or sadness, or any emotion that lay in between. It was because of the way he whispered 'Yukina', like the name was a porcelain doll, and anything more than a whisper would break the only memory he had of her.

It was hard to imagine a twin for this demon. That something so special, something so precious, would have something exactly like it. Did her eyes promise the same loyalty her brother's did? When she turned around, did she vanish wordlessly into the night, too? Was she broken into a million pieces, stitched together and made to present herself a valiant warrior, as faultless as he was?

It was the silent curiosity he had of her, this 'Yukina', that drove the red-haired teen to innocently swear that he would find her. Not for the demon, although nobody can ever find out, but for himself. After all, how many chances can one get of owning two of the most priceless jewels in the two worlds?

I was late, but I knew he would wait. If we waited for ten years, after all, what was another couple of minutes?

As soon as I arrived, stepping on the puddles on the hard cement floor, he stepped out of the damp shadows and faced me. There was something different in him, something vulnerable in his eyes, something I was wise enough to capture in my memory; there was a big chance that I will never see this side of him again.

It was fear. Simple, undisguised, wide-eyed fear. Of us succeeding, or the plan failing, I didn't know; I took a brave guess and stabbed at the latter. Despite myself, and the knowledge that after today he would hate me for this, I rushed forward and pulled him close.

"This will work," I whispered. "I'm sure of it."

He stood stiff enveloped in my arms, and I felt his heart beating fast, pumping blood and adrenaline to feed the essential need to finally, finally take this step. Ready, finally, and yet… he smelt of trepidation. I buried my face in his hair and absorbed it, inhaling the musk of fear and chestnuts and braveness and insolence, willing it away, as if sucking and consuming it all would make everything suddenly better.

I couldn't blame him. The way I lay it out the plan for him was so simple, so pure it left no room for error. Perhaps this was what inspired this terror: steal the treasures, bargain them with Reikai for information on Yukina, find her. If any of the steps failed, there was no way to move on to the next. But he knew we had a good chance, our partnership to this was key: if there was anyone foolish enough to successfully steal from Reikai it would be me, I knew how to waggle my tongue to get what we wanted from them, he had the drive to find her wherever they pointed us, and he had the speed to evade us capture.

He didn't need to know that in my head, that plan had changed. And there was no turning back.

I've done the first step months ago.

Yusuke Urameshi, passionate high school boy. I had my eye on him for months, stalking him like a lithe deer until I knew him so well, it was frightening. But understanding him gave me confidence. His determination was unflailing, his principles honored, albeit sometimes executed in the most awkward of ways. But his passion with life assured me of my choice; that he would do it when needed, and that he take no offense.

Most of all, one day, take me in, and comfort me when Hiei's inability to absolve me would hurt the most.

And so Yusuke Urameshi was hit by a car trying to save a child's life. As expected, it was never investigated why the child was in the middle of the road, conveniently located on a street where only Yusuke was close enough to save him, or even more importantly, why the driver suddenly found himself losing control of the car. Reikai was just glad enough to swoop down on the chance to form their precious Reikai Tantei, bargaining the lad's life with the Spirit Detective job. And Yusuke would take it; I had no doubt about that.

It wouldn't be far enough after discovering their precious treasures stolen that they would send him after me and Hiei. He would do as I planned, he would lend me his life, and he would take Hiei… it was just one of the unfortunate side effects that Hiei would be unable to do anything about it.

Holding the small demon in my arms right now, I trembled. I was sure it would hurt, the pain already starting now. I tried my best to think of any other way, I was a fox sniffing through all possible roads and alleyways, but it would always lead me to this… the only way he would let me take the chance. It was an insane and elaborately complicated plan anyway, but it had to work. Even if it meant breaking all the promises I made, letting go of the two biggest treasures that were almost in my hands, and living a life serving the spiteful church that was Reikai, for Shiori's love… it just had to.

Slowly, I let him go, knowing that I had just marked the decision to take the final step to this convoluted dance.

"Ready?" I whispered.

One strange afternoon, resting above his tree, the demon had a thought that frightened him to his core.

It started innocently enough; he was prepared for a completely lethargic day, glad the afternoon sun angered everyone in the planet except him. Thank god for his mixed origins; it was the one thing he could gloat over the treacherous ice maidens.

That was what triggered the thought of his sister and how, strangely, this was the first time he thought of her for months.

He adjusted his body as he pondered on this for a while, and to help him, he decided to picture her in his mind; the only place where she ran freely, playing in the wind and the snow in a peaceful storm, laughing like a song. He pictured her like his mother and all the ice maidens in their village, and he wondered if her eyes were red, too. In his mind she was still a child, innocent and crystal-like in her frailness. He didn't know anymore if he'd just made this actual memory up, but nobody can take away this image he had of her. Nobody.

Except that… except that this time, instead of snowflakes raining down at her gentle kimono, it was rose petals.

And this thought, that the owner of the rose petals have managed to enter his mind and invade a sacred memory, rocked the very essence of his being.

Since when had he opened himself so fully? The teen's thoughts had wound innocently around his own through the years, it was hard to determine where his ended and where the demon's started. His awareness was like ivy, slowly creeping through the walls, childlike and playful in the way it wound around all the corners and sides, caressing him and flirting with him like a siren to a sailor.

Whose idea was it to look for Yukina?

The fact that he couldn't determine didn't bother him as much as the thought that with a single breath of energy from the fox, ivy can easy crumble down the biggest of mountains.

I held the hilt of the sword in my arms, holding it in an awkward way; I was no master of the weapon, as any observer would note. But I need not master the art, a sword was simple and its one end had a singular purpose. It wouldn't take an idiot to do what he pleased with it.

I knew I was taking too much time, the precious seconds ticked like a vulture circling overhead. But I had the three treasures in my arms, and all that was left was to escape; I was sure Hiei had done his part, waiting outside this corridor, silencing the whole place with invisible wards. It should be a breeze.

A breeze, of course, in the whole whirlwind of thoughts and emotions rushing through me as I slowly made my way back to him.

Somewhere far away, where everything was well and fine, and the women in our lives did not exist to complicate things for us, I knew that this would be celebrated as the one of the best heists in demon history. Hiei and I would be heroes, unseen lords in our world, cheered for in bars and pubs and passed on as legends to any demon son who would go to sleep. In there, I was youko, needing no love from the sirens, gloatingly happy over the concealed fact that aside from enjoying a venomous reputation, I owned the biggest treasure in the three worlds: the trust, loyalty, perhaps the love, of the forbidden one.

The irony made me laugh out loud: in a way, I had that in this world too.

If it weren't for human weakness, I spat inwardly, I'd have it until it did not want to be owned. Until it broke free. And supposedly, along with its twin.

But it would be a matter of seconds before I'd lose it all.

The darkness surrounding the castle corridor comforted me in two ways: one was that I always worked best in the darkness, the shadows concealing stealth, my power my eyes and ears. Second was unique to this moment: it hid me from my own guilt. I felt like dissolving into it, melting along with the nothingness, because isn't that what I was, at the end of it all? Ashes to ashes, those that owe their life from the earth will eventually give itself back to it, fueling life's cycles. At this point, what was I but a treacherous creature about to strike the only thing that keeps it alive? In reality I could turn my back away to this defection as easy as her breathing life into me, but then, the cycle would not be complete, wouldn't it?

I double checked everything mentally, hurriedly, like a real mastermind should: Yusuke Urameshi is now spirit detective. The mirror of utter dark will heal Shiori. Yusuke would share his life with me in exchange. There was a chance we could both live.

And if we did, I needed a chance to be free from Reikai prison. Thus, the most important aspect of this plot: the decoy. Make them think he was the mastermind.

Ghostslayer's control over the mind of its victims was absolute. As I held the sword, its power assured me that indeed, its curse was strong enough to command even B-class demons. Strong enough to contain the flames. Oh, Hiei would be aware, for sure. But all he'll be able to do is watch, look at the damage his body is making, stare blankly at my treacherous eyes, shake with anger as his body battles Yusuke Urameshi and ultimately be led into his own defeat.

I need not be reminded that when I release it, the trapped flames would have brewed enough energy to consume me, whole.

The light breaching through the door told me that I've reached the end of my hiding. It was time. No turning back. I took a deep breath to steady myself, and turned the knob.

He had a smirk on his face as soon as I emerged with the three treasures, the sword especially held in my hand. As I walked up to him, right before I plunged the sword into his chest, I knew that the only way to pay for my sin was to let him take revenge and one day, plough the sword into my own heart.

Notes

Just to clarify everything, here are the five betrayals of this arc:

1. Kurama showing the ink stains of his palm was a threat to Hiei, knowing the jagan's weakness. This was a clear violation of his earlier promise to protect Hiei.

2. Kurama was the one who planted the idea of finding Yukina in Hiei's head. The sneaky thief wanted to own both treasures.

3. Just as he planted it, the fox also came up with the solution of the heist of the three treasures to bargain with Reikai information. But in the end, he had to change the plan to suit himself and save Shiori. This meant that finding Yukina was deprioritized.

4. The ending to this. Kurama plunging Ghostslayer into Hiei.

5. We all know what will happen next: Kurama takes being a traitor to a whole new level and actually smears his blood on Hiei's jagan in the warehouse fight.

Questions that must be in everyone's minds:

If Kurama had just told Hiei the truth, that his mother was sick and he needed the mirror of utter dark to save her life, wouldn't Hiei have shared his life too? What did he need Yusuke for?

The mirror of utter dark wouldn't accept Hiei as much as it had Yusuke. It was the purity of Yusuke's intentions, and the willingness of Kurama to sacrifice, that would save Shiori and make the mirror grant them both their lives.

Why did Kurama need to Ghostslay Hiei?

Kurama needed Hiei to act like a homicidal freak so when they get captured, Reikai would think Hiei was the mastermind. At this point, remember that Reikai did not know that Kurama was youko. It was a risk they'd discover if they investigated Kurama too closely. Kurama was confident enough in his negotiating abilities; he would save him and Hiei's ass from eternal damnation if they helped Yusuke and served as tantei.

Also, Kurama thought that Hiei would not have agreed to use the mirror to save shiori. Ironically, I think he would have. But Kurama just didn't understand yet how attached Hiei had been to him at this point.

Why was Hiei dumb enough to not know Kurama's plottings

Because he's still a busy demon; he had other things to do other than read Kurama's mind.

Okay that was a lame excuse. But I honestly feel that he was introverted enough to not prod Kurama, even if he felt something was wrong.

Thanks for reading! This is totally new for me, I usually like creating my own worlds instead of logical plausibility, so let me know what you think.