Title: Metronome

Crossover: Sailor Moon/ Yu Yu Hakusho

Universe: I'm taking things from both anime and manga of both series.

Timeline: Post Stars season/ Pre-Dark Tournament

Pairing(s): Hotaru/Hiei (probably won't be anymore)

A room. Walls, cold and white...small, closed space.

She carefully arose from the floor where she had been. How she had gotten here, what had happened beforehand...none of it she remembered, there was only the room.

It was quiet.

Expressionless, she looked around. She felt no fear, no anxiety, at the realization of her sudden surroundings. Directly across from her she spied a doorknob, her exit from this small white prison. It was white like the room, only discernible as a door by the knob that protruded from it. She gently grabbed it and pulled, twisting it every which way but to no available. If someone had put her in here they certainly didn't want her finding her way out.

She backed away slowly, looking around the room again, the white a near blinding light to her purple eyes. She trudged around the room looking it over, mouth pursed into a straight, thin line as she did so. It didn't feel like the safest place to be in, but neither did she feel any danger in this place.

It appeared that the door that was melded into the wall's white hue was her only exit and walked back over to it. She pulled the knob again and twisted it again, this time, it clicked and she was released.

The door creaked open as she pushed, no blinding light meeting her on the other side as she had anticipated. Instead, the world on the other side of the door faded to a light gray and other pastel-hues she couldn't name. The world looked old...was this the past? But where in the past, she questioned looking around her...there were some trees to her right, to her left a cliff that trailed off downwards to a rocky ravine she was sure...she didn't want to hazard a guess by leaning over to look. Turning to look behind her, the door had vanished and the white room along with it. No sense in turning back now, especially not with the door gone.

Walking forward, her bare feet meeting the cold ground of the rocky cliff on which she stood, the sound of rushing water entered her ears. A river nearby most like, she remarked, looking to her left again...someone was there. Quickly did she hide her person behind a nearby tree...it wasn't the best camouflage with its dead and rotting trunk and lack of any noticeable limbs but it would do.

The person who sat by the cliff's edge was a boy with spiky hair, color wasn't an option but she could tell it was darker hued just as her own. It was hard to gauge his height or his age since his back was turned to her, but he appeared not to notice her for the moment.

She stared at his backside, eyes locked on him as her expression finally changed to one of surprise and curiosity. What was this boy doing in this place?...wherever 'this place' was exactly. She had yet to discover that crucial clue.

Suddenly, her body tensed, the hair on her arms jolting up as an electric surge went up and down her spine...someone or something was coming closer...and fast. She ducked again behind the tree trunk, only this time, it was at an angle neither the boy or newcomer should see her...she certainly hoped so.

What appeared next was a monstrosity of a creature...a demon. He howled, possibly a war cry, and with a lumbering sprint charged with weapon held high straight at the boy. She turned her head, things seeming to run in slow motion now, to warn the boy but he was already on his feet; his own weapon drawn.

What happened next was a blur of a battle, her own eyes in this human form too slow to catch on. Had she been transformed and in a celestial body, now that might have been a different story...she might could have at least seen the boy's face. Either way, he was fast...very fast...inhumanly fast. He must be a demon also, she decided, although he was more human-like than his opponent who, despite his giant weapon, was quick enough in his own right.

Suddenly, there was a sparkle...was it a tear? A drop of blood? She moved out from behind the trunk to see better. Something about it...she had to know. The boy stopped his movements, realizing what she must have and locked eyes with her. If everything hadn't already felt like it had slowed down, now would have been the apt time. She quickly tried to register all of his features before she bolted from behind the tree, quickly trying to reach out for his fallen object: a necklace with a single gemstone attached to it. It sparkled despite the new-found gray coloring of her world, and she knew it was special...it had to be protected.

She was a slow runner but she could get there in time if neither combatant halted her, and luckily both seemed too occupied with battle. She watched as the necklace bounced along the ground before finally rolling off the cliff side, just out of her fingers reach, and plummeted to the river below. She panted small breaths, staring wide-eyed down into the canyon...how could she have failed at such a simple task? Would the boy blame her for not catching it now? Would he hate her?

That same surge from earlier traversed her spine and she turned, short black hair forming a halo around her head in mid-air. The demon creature was there, ready to attack her...she couldn't defend herself without her henshin stick and she wasn't going to depend on the boy. She closed her eyes and waited for the weapon to fall on her...but it never did.

The cliff edge, unstable, collapsed beneath her timid weight and she fell just as the necklace had.

When she awoke, she found herself still within that gray-colored, pastel world. If this had been a dream, shouldn't the fall have woken her up? What about the old wives tale about falling in a dream; if you failed to wake up before you reached the ground, you were dead in real life. Taking who she was into consideration, this was not an unlikely ideal.

She lay trapped between rocks in the river bed, her arms having snagged at an angle that supported her tiny weight and held her there. Who could tell how far she floated down stream, if she had at all. And what of the necklace? Had it too become caught? Cautiously unwinding her limbs, she submerged herself into the waters of the rather deep but slow moving river. She looked along the bottom, spying something shiny as she did so. Although she was rather sore, the fall had left her virtually without a scratch.

She swam to the bottom and reached out for the object, drawing back to find only a glinting pebble in her palm. This was not the necklace she had seen. Disposing of the rock, she swam back to the surface, taking a graceful gulp of air as she did so and continued swimming to the riverbank. Perhaps the boy had followed her somehow and retrieved the necklace himself but something told her it was unlikely.

She honestly had no business looking for it...a lost trinket from a stranger was really not a problem she had to deal with, but still, she felt compelled to find it. Something powerful was drawing her to it.

Her purple eyes scanned the slow moving river and its other bank...it had to be here. Surely that gemstone was large enough to keep it from being cleanly swept away, but it was such a tiny thing...there, on the other side of the river, mixed with a cluster of rocks. It had to be there. There would be no mistake of it, no misleading shimmer of a mere pebble.

She stepped gingerly back into the river, perfectly content with walking the length had the river been shallow enough to walk in. She paddled her way over, resting a hand on one of the rocks in the cluster. Of course, it had somehow gotten stuck...the flimsy cord the boy had been using as a makeshift necklace had gotten tangled. The only way to release it would be to cut the gemstone from its binding...but with what? Clad only in a simple shift, she carried no weapons on her person, nor were there any in site. She wasn't strong enough to pull it off, a metal clasp on top of the gemstone made sure of that. The only thing she could think of would be her teeth...the cord was weak with wear, it shouldn't be too much of a problem to break it.

Carefully, she placed her lips around the gemstone, teeth set on either side hitting the rope. Then, she pulled. She could feel part of it giving away but it would take more than a single pull. She paused a minute for breath and rest, readjusted her mouth's grip, and pulled again. She did this a number of times over, convincing herself that the stone was firmly stuck until finally it pulled free with a fierce snap of the cord.

She might have swallowed the stone in surprise had a tiny piece of cord not remained wrapped around the metal clasp. Holding it within her teeth, she swam to the closet bank and rested, dropping the stone into her palm. She breathed heavily, tired from her retrieval, and stared at the tiny stone that lay in her hand. It was very pretty, had an unbelievable shine to it...it felt otherworldly, and yet...it felt very warm. The stone itself was cold like ice, but the aura it gave off was hot like fire. It was so...so beautiful.

Her eyes began to feel heavy then, something was pulling her back...away from this gray world. She didn't fight it, merely clutched the stone within her hand and succumbed, collapsing onto her side into what looked like a deep slumber.

Hotaru awoke with a gasp, sitting upright in bed.

Her alarm clock was ringing, having slept through the appointed time at which she had set it. Her whole body was wracked with sweat and she felt weak. She quickly turned off the clock and flipped the covers back to get some air.

She glanced down at her hand...it felt warm, but there was nothing in it.

As a senshi, she was no stranger to the odd dream every now and then, quite often anticipating them whether they be signs of things to come or memories from a past life. Due to her own special powers as Saturn, she could also tell when calamity was to appear just as she had when Chaos possessed Galaxia. Luckily, her warning had not gone unheeded by the other senshi and with the banishing of Chaos, the world was once again safe; an end to the Sailor Wars had finally come.

Despite all of that, dreams and memories continued to flood in every now and then...perhaps preparing her for the role she would take on in the 31st century as a guardian senshi of the new princess, Chibi-Usa. However, that was still many years from now.

And...why would she be dreaming about a boy and a gemstone? What purpose did the two of them serve?

The stone had nothing to do with her she was certain. The Taioron Crystal given to her by her father while under his own possession had shattered at the defeat of the Mistress 9; the Deathbusters power source being no more. Her own Saturn Crystal, granted to her by the spirit of Saturn, remained strong within her, ready to activate again once her powers were needed. It had only been two years after the defeat of Chaos...would the fourteen year old really be needed again?

Hotaru knew she couldn't think like that and moved to get dressed for school. Today would be a normal day, nothing to worry about at all. If there was something to worry about then Saturn would surely appear and warn her. It was odd to think at first that she wasn't exactly like the other senshi. Saturn existed separately from her it seemed...Hotaru could remember everything that happened while she transformed and whatever happened to be going on while she was transformed as Sailor Saturn and yet...she never truly felt like herself. There seemed to be someone there just below the surface, helping her out. Hotaru was strong in her own right, her healing powers nothing to be overlooked, but with Saturn's help she was unstoppable. Perhaps the relationship could most closely be related to that of Sailor Moon and Neo-Queen Serenity. They were the same...and yet not.

After she'd prepared herself for school, she headed downstairs. The house was empty, dark, and quiet...it would have been unnerving if she hadn't already been used to it. Setsuna would be at the Time Gates, while Haruka and Michiru traveled abroad for concerts and races. Setsuna would most likely be home to check on her later, the girl deciding it best not to tell the older woman that she was late for school this morning.

Walking past a tall grandfather clock, she read the time: 10:15. Not too bad, she had only missed homeroom and 1st period. She headed into the kitchen although she didn't feel like eating, settling with a glass of water as her breakfast. It wasn't too far from lunch but the feeling that rested in her stomach told her she wouldn't be eating any time soon.

Grabbing her things, she headed out the front door, a slow and steady walk towards the Mugen school.

"A little late this morning were we?" Setsuna questioned from behind her book, the older woman nestled comfortable into an armchair in the living room.

"Are you...mad?" Hotaru questioned, no sense in acting surprised...Setsuna always knew everything whether she let on about it or not. The girl was even tempted to ask how she knew but learned rather quickly that that was just silly to ask questions of that nature to Setsuna.

"Mad? I'm more concerned about you," the woman replied, laying her book down into her lap, "Did something happen this morning? It's not like you to be late for school or sleep in. Something on your mind maybe?" Hotaru's eyes wavered as she stared at one of her adoptive parents from across the room. Setsuna knew a lot, but the woman couldn't read dreams...that realm didn't belong to her. If Hotaru chose to lie about it, then Setsuna would have literally no way of finding out. She reached a tiny palm out to grasp the door-frame in which she stood,

"Have you...do you know of a type of stone that feels both hot and cold at the same time?"

"A stone?" Setsuna responded, confused, as Hotaru slightly grimaced and averted her eyes downwards. "That's seems a little random...what brought all this on?"

"I had a dream about that kind of stone...I touched it in my dream and that's how it felt. Do you think it means anything?" Hotaru questioned, melancholy attempting to cloud her face. She didn't tell Setsuna everything...the rest didn't seem too important for now. She barely knew anything about the boy to mention him.

"I can't say I've heard of anything like it...maybe it's something you read in a book?" the woman smiled playfully trying to keep the mood light. Hotaru nodded although she didn't agree...couldn't be that. If only she had seen it in color the stone might have been easier to describe. Then again, maybe it really was nothing...her mind creating random things in her dreams maybe.

Setsuna watched with a motherly look as the younger girl headed upstairs to her bedroom, but squinted her eyes into a glare once the girl was out of sight. Something wasn't right here...why did that sound so familiar? Quietly she arose from her seat and headed towards the downstairs library she had claimed as her own. The Outers mansion had quite a number of rooms, but she only needed a small space to get her work done...her reading material on the other hand needed quite a bigger room.

The stone in question...was it something do with the senshi? All of the senshi possessed their Sailor Crystals, and both generations of Moon Princesses owned a ginzuishou. It didn't add up since the Sailor Wars were over, no more power-ups would be required or even granted by their guardian planets. So what could it be then? Rocks of the Earth normally only felt one way and didn't hold an other-worldly feel about them either...the tone in which Hotaru described it made her sound afraid of it, hinting to Setsuna there must be some power to it.

She quickly browsed volumes that ranged from topics a-z; psychology, philosophy, medicine, history, biology, etc. She only placed the most reliable sources on her shelves for these areas of study. At the back of her collection, tucked into a corner, were books on the supernatural. She was a senshi and had seen plenty of unusual phenomenon, but she was also a scientist in her spare time...not to mention, the authority on the realm of the supernatural simply did not rest in human hands. Very few reliable works by humans sat here...all of the others simply read like comic or joke books to her. The real ones were written by those on a higher plane, some even by demons themselves.

Pulling one out, she skimmed and scanned pages. It was a hand-drawn manual by an explorer who had accidentally stumbled into the Makai world, or Demon World as it was known. Makai was certainly not a place for humans and it was miracle the man had survived as long as he had, but of course, it did help that the man unknowingly had demon blood flowing through his veins. Weak though it may have been, it was still there. He became more and more fascinated by the world and began to record everything he saw including the different types and powers of the demons he saw there. Obviously, the volume was the only one of its kind and it was nowhere near completion...just a few silly scribbles by a nameless explorer who unfortunately met his end in the world he began to fancy so much.

Finally, Setsuna came across what she was looking for. It was a fresh chapter on his encounter with a blue-haired maiden who called herself Yukina. She claimed to be an ice demon, a kōrime, and...of course the man spent another page and a half marveling at how the woman was able to control her pronounced element over ice. Once back on topic, she continued to read closely...the woman mentioned she was searching for her brother, never gave a name, but said that she would know it was him as long as he was wearing a special necklace. In the corner of the cracked parchment paper of the book was a small observation drawing; a small circle attached to a piece of string.

Hotaru hadn't given much description on how the stone looked, but Setsuna was beginning to find the similarities a little strange. A female demon who could control ice who carried a mysterious gemstone with her...

The explorer went on to say that she would not allow him to touch it for it was too precious an object, but said that despite the naturally cold temperature around her, he could feel the slight presence of heat radiating from the necklace.

It was truly strange that Setsuna had thought about this old journal...she picked it up as more of a convenience than anything else. Although it wasn't truly her place to worry about it, she knew well enough that Makai and the human world were not to mix. And throwing the realms of hell and paradise into the mix only made the problem a lot greater. There were reasons the worlds had boundaries and barriers surrounding them...they were simply not meant to mix. Could Hotaru's dream mean that something was to happen to those barriers? Setsuna couldn't stand by and let that happen.

The green-haired woman bit her thumb, focusing the weight of the old journal onto one hand. Perhaps it said more, some kind of clue yet to found and so she read on...

The explorer inquired more about the stone, obviously clear that the stone was rather important. Yukina explained to him that it was called a hiruseki stone. It was a precious stone that a mother kōrime cried (the tear she would shed would then crystallize into stone) for her child after they were born. The woman explained that she had a twin brother who had disappeared from their homeland, thus explaining her journey to find him. All she knew of him was that he too would carry a hiruseki stone just as she did; the other kōrime had never left their homes as she had effectively ostracizing herself as well.

More ramblings after this...Setsuna flipped a few more pages filled with sketches of the stone and its proposed powers. The book ended after this, Setsuna knowing the ending of the explorer was actually the ending of his book. It was his inquiring about hiruseki stones after this that became his undoing. That's right...now it was coming back to her. Hiruseki stones were precious not only to their owners for its sentimental value but to its monetary value by others...asking around about one would only invite trouble in Makai. He'd been ganged up on and was demanded to reveal the location of the kōrime and refused.

Setsuna closed the volume and replaced it on the shelf. A story that would never be told, huh...

She stood motionless in front of the bookcase. Should she tell Hotaru or not? Would this come back to bite her in the end...would it put Hotaru in danger? It was unlikely that the girl could find anything on her own with the small bit of information she had. Humans would most likely laugh it off saying such a stone didn't exist or say that what she had said made no sense. She would be in no danger by asking around in the human world. Still...was there some outside force to deal with here? Saturn would have warned them and she would have seen a disturbance in the Time Gates if so.

Setsuna sighed, she would have to tell Hotaru about this if only to quell the girl's fears and concerns. Setsuna would have to keep an eye on her, regardless.

A/N: And that's where I decided to end the first part of this. It's one of the many Hotaru/Hiei ideas I have and never posted but I really liked this one since I wrote it in a much darker tone than my other stories and it will probably remain pretty dark-toned for awhile. It might be confusing at times too but bear with me, everything will make sense in the end. YYH characters are set to show up next chapter.