When Yukari was sixteen, she lost her heart. It was not an accident, like most cases of lost hearts. It was a deliberate move, one made after years of living in the small village she spent all her life in. At the age of fourteen, Yukari had come to the conclusion that having a heart was pointless and dangerous. After all, it could get broken, and a broken heart took a while to mend. It could get stolen, and that would cause a whole lot of trouble, wouldn't it? The heart was the seat of emotion and each heartbeat caused nasty, complicated feelings that really just got in the way of everything. Yukari got scared. She got nervous. Most of all, she got lonely. Without a heart, all of those pointless emotions would go away.

That was that. Yukari didn't need feelings. At the age of fourteen, Yukari started to make a clockwork heart, and at the age of sixteen, she finished it. It went tick tick tick instead of thump thump thump and overall looked very elegant, silver and chrome, its little gears whirring away, a tiny pendulum oscillating in the center. Once she created it, Yukari went to a surgeon's in the city, her first trip outside the village, and presented him with her clockwork heart. The surgeon had looked at her, aghast.

"Why do you want to lose your heart?" he had asked, weighing the clockwork heart in his hand. "You're so young. You haven't even fallen in love."

"I don't need love," Yukari had replied.

The surgeon made to protest, but Yukari handed him a hundred coins and he agreed.

So now, Yukari had a clockwork heart instead of a real one, and her thoughts became as logical and as clear as a clock itself. She donated her old heart to a university for research purposes. It was possible to get a new heart if you had a star's heart, but stars were rare, and Yukari had no intention of obtaining one. Her clockwork heart filled the space where her old heart lived. As long as something was in its place, there would be no danger of Yukari having a messy human heart again.

And that, Yukari thought, was that.

-xxx-

Tick tick tick went Yukari's heart as she walked down the path, holding up a lantern for illumination as she searched for a moondrop flower. She needed it for one of her experiments, but finding one was proving elusive. Such flowers could only be found at night when the moon was full, on a week with no sunlight, and even then they were rare, only appearing here and there in random places across the world.

Yukari was about to give up when she saw a bright flash of light to her left. If she still had her human heart, it would have skipped a beat in surprise, but her steadfast clockwork heart was never surprised. For such a precise creation to be affected would take something exceptional indeed, and bright flashes of light were hardly exceptional. Still, Yukari decided to investigate it, and she walked over to its source.

There, in a clearing, was a pale girl lying on the ground, dressed in black and pink, her eyes closed and her hair so blonde it seemed white, faintly sparkling in the night. There was a ring of scorched grass around her. Yukari's eyes widened and her fingers loosed, imperceptibly, on the lantern's handle. There was no doubt about it. This girl was a fallen star.

Yukari took a breath. She had come looking for a moondrop flower, but a fallen star was a far more appealing object to research, and she immediately ran towards her. The burned grass smelled like rust and stardust, and Yukari's feet crunched the dead leaves. She knelt down next to the girl.

"Hello?" said Yukari. She put a hand on the star's shoulder, smooth and cold under her palm.

The star groaned. Then, slowly, her eyes fluttered open and she stared at Yukari for a moment, blue eyes uncomprehending, before they widened and the star immediately scrambled backwards, yelping as she lost her balance and fell back down to the ground with an 'oof'.

"Are you alright?" said Yukari. She walked towards the star and crouched down before her.

The star swallowed. "Are you going to...to take my heart?"

Yukari shook her head. "I don't need a star's heart. Hearts just get in the way."

"Oh," the star said, but she did not relax, her eyes still wary. It would seem that stars felt emotion like any other human. However, Yukari mused, given the strength of a star's heart, would a star's sense of emotion be similarly magnified? "What's your name?"

"Yukari. What's yours?"

"Yukari? That's a weird name," the star frowned. "I'm Ia..." she trailed off and glanced at Yukari once more, her eyes slightly narrowed now. "Wait." Ia leaned her head to the side, slightly closer to Yukari.

Tick tock tick, went Yukari's heart, and Ia pulled back as if stung.

"Your heart," she said. "There's no heartbeat. Did you lose it?"

"I got it replaced with a better one. I made it myself."

Ia's brow furrowed. "Oh."

Yukari waited for a few moments longer, but Ia had fallen silent. The ticking of her clockwork heart echoed loud in Yukari's ears, and after some time, she figured that Ia didn't much feel like talking anymore. That was probably the most she would get out of the star at the moment. Being without a human heart, Yukari could think of nothing more to say and nothing else to do, so it was with a cordial nod when Yukari got back up to her feet.

"Well," said Yukari, "it was nice meeting you."

Ia stiffened and stared at Yukari. "Wait! You're leaving?"

"Yes," said Yukari. "There's nothing else for me to do here."

"No," said Ia, her voice tight. "Wait, can you...can you help me?"

"What do you need?"

Ia straightened up. "I want to go back up to the sky," she said.

Yukari frowned. "That has never happened before."

"It's never happened before, but there has to be a way," Ia was talking rapidly now, her words all panicked and flowing together. "All the other times, it's because the stars...the other stars all died here. But if I could find a way to escape, if there was some kind of...of magic, or something, anything, that could get me back up there..." Ia trailed off, and then her shoulders slumped. "But if you can't, then I'll do it myself. I know there's nothing in it for you, but if you could just help, I'd be so grateful..."

Yukari stood still for a while, thinking. Her clockwork heart was untouched by Ia's pleas. If she had her original heart still, if it wasn't already cut up into chunks and being researched at the University, perhaps she would have been touched, touched enough to want to help for nothing more than the gratitude of a fallen star.

However, Yukari's heart was stone-cold. Ia's pleas slid off of it like water.

Fortunately for Ia, Yukari's curious personality remained intact, and a part of her wondered - was it possible to put a star back in the sky? True, it had never been done before, but Ia was right. All the other times, the stars in question had their hearts taken, and a star with a forcibly removed heart was a star that was dead. If they had lived for a few more days, or a few more weeks, a few more months...would they have found a way back? There was so much magic in the world, and there was the legend of the Babylon candle...

And Yukari could be the one to find it. She could potentially discover, potentially create the legendary Babylon candle. Her clockwork heart went tickticktick in excitement, the pendulum swinging faster, the gears speeding up.

"Please help me," said Ia, her voice soft.

"I'll help you," said Yukari.

Ia's eyes widened and she looked up at Yukari. "Really? You...you will?"

Yukari nodded. "Yes."

Ia gasped and clapped her hands together, a wide smile spreading on her face. She bounced up and down on her heels. "Thank you! Thank you so much!" She bound forward and hugged Yukari tightly before pulling back. "Where do we go?"

Yukari waved her lantern in the direction of the path she came from. "For now, we can go back to my home."

-xxx-

"The thing about a star's heart," said Rin, "is that it's most effective when it's glowing."

Len frowned, ducking under a branch. "Glowing?"

Rin nodded, face solemn. "Glowing. When a star is happy, see. A sad star's magic is nowhere near as potent."

Len supposed his sister would know this kind of thing. She was an apprentice witch, whereas Len would be taking over the family business as a butcher. It was far less glamorous than being an apprentice magician, true, but Len was good at cutting things. When they were younger, playing at adventuring in the woods, Len would always be the fearless warrior. Now, he was older and all he wanted was to go home. So a star fell. Big deal. It wouldn't help him with his job. "What do you want a star for?" he asked.

Rin rolled her eyes. "What do I want a star for? It's obvious! I'm a witch-in-training, right?"

"Right..."

"Well, that's magic," said Rin, "and a star's heart is one of the most magical things of all."

"I don't see why you need it though," Len muttered. "You're just an apprentice witch."

"Properly used," said Rin, "a star's heart would give me more magic than my teacher, as much magic as first-rank witch! These things only come around once a century!" Rin's eyes were aglow. "Len, if we get our hands on this star, we'll be set for life!"

"You mean you'll be set for life," Len said. "I don't need a star's heart."

Rin snorted. "You're saying you don't need all the money even a sliver of a star's heart could give you?"

Len hesitated. The Kagamines weren't exactly rolling in coin. "Money?"

"Money," said Rin. "With a star's heart, we'll be made." She rubbed her index and thumb together. "Add on the magic, and the luck, and the youth, and the speed, and the strength...we'll be famous, Len! Legendary! Every single person who obtained a star's heart became great."

Len thought about it. Len, the Legendary Butcher. There was, he had to admit, a certain ring to it. "Yeah..."

"Right?" Rin grinned. "You're with me, right? Let's catch a fallen star!"

-xxx-

Ia wasn't used to the ground. Up in the sky, all she did was shine with her brothers and sisters, and there was no ground in the sky. The twigs and pebbles on the rough road hurt her feet, and as she walked, she winced. Did humans always go around like this? Centuries of looking down at the earth from above had hardly prepared her for actually walking on it.

"Are you alright?" asked Yukari. From this distance, Ia could hear the ticking of her clockwork heart. It was...Ia shuddered, wrong. Humans weren't meant to live with clockwork hearts. There was a remoteness in Yukari that was frightening, a feeling that only half of her was here, the other half lost and gone.

Still, Yukari was helping her, so Ia decided not to complain. It was more than she could have hoped for. Perhaps it was better that she ran into a human with no heart; Ia was old enough to know what happened to stars when they fell. A heartless human, cold as they may be, would certainly have no need for a star's heart.

"I'm okay," said Ia.

Yukari frowned, then her eyes, a cold shade of light purple, dropped down to Ia's feet. "You need shoes."

"Shoes?"

Yukari nodded. "To protect your feet. I can make a pair for you when you get back, but for now, you can use mine." She kicked off her shoes. Ia stared at Yukari's feet, pale and incongruous on the path. If Ia wore Yukari's shoes, wouldn't Yukari's feet get hurt too?

"No...thank you," Ia said. "I don't need to wear your shoes."

"You are unused to walking," Yukari said, "and having your feet hurt would only slow us down."

Ia frowned. "But..."

"Put them on," said Yukari, and it was with a sigh when Ia gave in, slipping the shoes onto her feet. They felt strange, loose, floppy - a bit too large for Ia's feet, but still wearable. Ia wriggled her toes and watched the fabric of the shoe move with them. Yukari looked at it in quiet satisfaction.

"Better," she said with approval, and then, to Ia's surprise, she took her by the hand. As a star, Ia had never touched someone before, and the feel of Yukari's hand, cool and soft, made the back of her eyes prickle. Ia was so far from home, marooned on a hostile world, and her only companion was a strange girl with no heart, simultaneously there and not there. She was scared and lonely, but there was no one else but Yukari. Holding someone's hand was a comforting gesture amongst humans, but Ia got the feeling that Yukari was doing it only to aid Ia in walking, so the comfort was lost.

Ia wiped her eyes with her other hand. "So," she said, "do you have any idea of how to get me back home?"

There was a bit of a pause as Yukari thought. "Years ago," she said, "people said the fastest way to travel was by candlelight."

Ia looked at the lantern Yukari was holding. "Like the thing you're holding?"

Yukari shook her head. "I am holding a lantern," she explained. "What people meant was a Babylon candle. You light it, think of where you want to go, walk, and you'll be there."

Ia wrinkled her nose. "What's the difference between that and this?"

"Well, according to the stories, it only takes you a few steps. You don't travel the true distance of things. It's like..." Yukari paused. "It's like the road bunching itself up under you. But it works for anything, any kind of distance. I bet it'll work for stars too." There was a faint tinge of excitement in Yukari's voice now, whereas before, her voice was flat and unemotional. So she can feel, Ia thought, but Yukari was still talking. "It could just be a legend, of course, but I think it's possible. It's just magic. Just magic and maybe some alchemy."

"Are you good at magic?" asked Ia.

Yukari nodded. "I gave up my heart so that I can learn things better," she explained. "I don't need to waste time with people if I could spend time learning and exploring new things instead. Feelings are inefficient. Back when I had a heart, it went places it wasn't supposed to go. It went in my throat when I was embarrassed, it dropped like a rock to my stomach when I felt sad, it shook when I was scared. A clockwork heart is much better," Yukari put a hand over her own. "It only does what it needs to do, which is keep me running."

Ia frowned. "That doesn't sound right."

"Well," said Yukari, "maybe not if you're a star. I understand from my research on the subject that stars are highly emotional. The reason why there's so much magic in stars is because of all the emotion they have in their hearts."

"Right," said Ia, "so if all you have is a clockwork heart, then how can you do magic?"

"This heart has simulated emotion capacitors for the magic."

"That doesn't sound very powerful."

"I don't need to be a powerful witch," said Yukari. "All I need is to learn and do research. This is enough for my small needs."

"But then how can I get home? If a Babylon candle is legendary, then..."

"Oh," said Yukari, "well, if we can develop a sort of theory or formula for it, then we can bring it to the University and one of their witches or wizards can make it. I gave them my heart after I got my new one, and I'm sure they're finding out all sorts of things."

Ia stopped walking and stared at Yukari, horrified. The mere thought of donating one's heart to a university was one that was completely repellent. A part of Ia couldn't help but to wonder as to what kind of person Yukari was before she lost her heart. Had she always been like this, or at least, aspired to be? Was there a time when she was as free and as emotional as any other human?

Yukari turned to glance back at Ia. "Is there something wrong?"

"You donated your heart?"

"Well, yes," Yukari said. "Most of the time, people are very finicky about their hearts, so there's hardly any research on them. I donated my heart to benefit research and further understanding. It's the logical thing to do."

Logical. Yes. From here Ia could hear the calm, impersonal ticking of Yukari's heart. A part of her was repulsed. A heartless human was hardly a human at all. But at the same time, Yukari had treated her kindly enough so far. Ia had no illusions about how most humans would treat her, after her long years spent observing from above.

"Are you feeling unwell?" Yukari inquired. "Is the atmosphere of the earth distressing to you? You are from the sky, so I'd imagine gravity-"

"No," Ia murmured. "I'm fine."

-xxx-

The star was clearly uncomfortable in Yukari's home, though Yukari could not imagine why. She had done everything she could have done as a human host to make Ia comfortable. She had asked Ia if she ate, and Ia had responded that stars dined on sunlight and moonlight. Such a thing was obviously impossible unless Ia fed on radiation. Although, stars feeding on radiation seemed strangely plausible. Yukari made a note to research this later on. Still, she had served the star tea, and Ia took halting sips of it, wincing at its heat.

As she waited for the star to acclimate to her new surroundings, Yukari shut and barred her windows. Given her strange reputation in the village, the fact that she now had a guest was one that would seem incongruous to the town. Nosy investigation from her neighbors would be an annoyance and, in the worst case, would result in the star's death. And the star, Yukari felt, was Yukari's responsibility.

"Do you live alone?" Ia asked.

Yukari nodded as she sat at the table. "Sort of. My parents were researching trolls. My father was a part-time troll hunter and my mother took some of them apart. They synthesized a potion that they thought would give humans troll-like recovery abilities. However, what happened instead was that they both underwent petrification upon sunlight."

Ia's eyes widened. "That's horrible! I'm sorry."

"That's perfectly all right," said Yukari. "I'm currently looking at the leftover notes from my mother's research to reverse the process. For now, though, my mother serves as the coathanger and my father is rooted outside in the garden."

"Why?"

"Too heavy to move," Yukari explained. "He is a bulky man and now that he's made of rock, he's even heavier. I estimated that it would take two and a half me's in order to move him. The villagers will not help me. To prevent erosion, I put an umbrella over him. I do not want him to be cured without a face."

To Yukari's confusion, Ia laughed. It was an unusual reaction to what Yukari considered a tragic story.

"Is that amusing?" Yukari asked once Ia's laughter died down.

"I'm sorry," said Ia, still smiling. "So you aren't completely heartless."

Yukari frowned. "I told you, I have a clockwork heart. I am not 'heartless'."

"Okay," said Ia. "But why won't the villagers help you?"

"They don't like our family," said Yukari, and then she paused. "Well, they don't like me, to be more exact. They think I'm strange and that the petrification of my parents was my fault."

"But it's not," said Ia.

Yukari shrugged. "That doesn't matter." She had never talked so much with someone before, and her throat was starting to hurt, unused to this much communication. Bad, Yukari thought. She limited her speech to twenty words per minute. "People are irrational. This is why I donated my heart."

"But doesn't it get lonely?" Ia leaned forward. "What were you like before you lost your heart?"

Yukari didn't especially like thinking of the way she was before. She was an easily frightened, shy, and nervous girl who got bullied a lot. It was incredibly pathetic, and also, incredibly lonely. Her father, being a troll hunter, was unsympathetic, and her mother was always in the lab working on some alchemical formula. But ever since Yukari lost her heart, she didn't care about that anymore. Loneliness was no longer an issue. Though she couldn't relate to people anymore, it was a small price to pay to avoid the pain. "Inefficient," said Yukari.

Yukari's tone was curter than she realized, and a brief expression of surprise passed over Ia's face before she sat back. "Oh."

There was a long pause, during which Yukari poured herself a glass of water. Then, Ia spoke again.

"Did you get your heart broken by someone?" she asked.

The mere thought of Yukari falling for any of the idiots who lived in town was one that was so amusing, Yukari would have laughed if she was capable of it. "No," she said, and then added, "Falling in love is pointless anyways."

-xxx-

"Well, that's just great," Rin said as she stood over the smoking ring of scorched grass. She could smell, faint but unmistakably there, the smell of stardust.

"The star's gone," said Len.

"Well, of course it is," Rin snapped, and she turned away. There was a group of people here now, other humans who tracked the centennial fall of a star, all of them looking disappointedly at the scorched ring.

One person, a girl with red hair, sighed as she stared mournfully at the ring. "Now what?"

"Now what? We have to find it, of course," said Rin.

Another person snorted. "Probably dead by now. We got any Trackers in here?"

There was murmuring in the crowd, and then a woman with long pink hair stepped forward. Without any introduction, she knelt down by the grass and ran her fingers along the scorched ring. There was a brief pause.

"She's alive," she said, and pointed west. "There isn't enough dust for me to track where she is, exactly. But she went in that direc-"

Before she could even finish her sentence, people started running down the road she pointed. She snorted and got back up to her feet, wiping off her hands. Everyone had gone. Idiots.

The woman, who will heretofore be referred to as Luka, turned and walked in the other direction. She walked for quite a while before becoming aware that she was being followed. She closed her eyes and then, quickly, spun around and reached out for the essence she sensed behind her.

"Ow!" cried out a voice, and Luka opened her eyes. She was clutching onto the arm of a blonde girl. Luka let go. The blonde girl stumbled back, rubbing her arm, glaring at Luka. "That hurt." She was standing next to a blonde boy now – twins, that was immediately apparent.

"Why are you following me?" Luka asked.

The boy and girl glanced at each other before the girl smiled at Luka. "Well obviously, we want to catch a star."

Luka sighed. "Well, the star is down that way, so-"

"Come on, give us a little credit," said the girl. "We're not stupid. You want the heart to yourself, right? We want the heart too. So how about we split it three ways?"

"No," said Luka, and she started walking again. The girl and boy caught up with her easily.

"Come on," wheedled the girl. "Just a sliver of a heart could give you a fortune. Why do you want the entire heart? I'm fine with sharing it..."

"That's none of your business," said Luka, "and I suggest you turn and walk the other way."

"Oh," said the girl. "Oh. Oh. Wait." She had a smirk on her face for some reason. "I know. I can hear it."

"Hear what?"

"Your heart!" the girl crowed. "It's all strange and it's not beating right – I know what happened. You got it broken, didn't you? But you can fix that with only one-sixteenth of a star's heart, so I don't know why you're so-"

"Shut up," said Luka, her voice going ice cold.

"Ah, I was right!" the girl was striking some kind of ridiculous triumphant pose. "Count on Kagamine Rin to get to the...heart of the matter."

At that pun, the entire forest went dead silent. The boy was cringing, eyes squeezed shut, and Luka could do nothing but stare blankly at Rin.

"Anyways," said Rin, "my name is Kagamine Rin, witch-in-training, and this is my brother Len, butcher-in-training. What's your name, Tracker?"

Luka had absolutely no desire to get to know the two. In lieu of an answer, she decided to walk away as fast as possible. Unfortunately for her, the twins were stubborn. Well, Luka decided, moreso Rin. Len seemed like he was just being dragged along for the ride.

"If I tell you my name," said Luka, "will you go away?"

"Of course not," said Rin, "but we're going to follow you, so."

"Oh my god," Luka muttered, and then she turned around and fixed the twins with a steely glare. "I'm Megurine Luka. Okay?"

"Megurine Luka...never heard of you," said Rin. "Are you a new Tracker?"

Luka sighed and turned around. It was going to be a long night.

Author's Note: A Stardust AU fic. Yes. No knowledge of Stardust necessary, though it is a good book.