Author's Note: Wow, it's been a while. I haven't written a fic in months, and the few I've put out in this past year are mostly one-shots (here be thank yous to those who read and reviewed those). I'm trying to see if I can write another multi-chaptered fic, but at the same time depart slightly from the certain melancholy that marks my work, so I came up with this. I was actually supposed to write this a few days earlier, but the trouble was that I didn't foresee the amount of research that had to be done. In any case, I've taken great pains with this. I hope you enjoy it! :)

Standard disclaimers apply.

Chapter One:
CHAOS THEORY

Imagine a butterfly.

It must fly, of course. So imagine the infinitesimal change in the atmosphere its small, dusty wings will cause. The slightest disturbance; hardly even a whisper of movement. But it will take off.

Now, imagine a hurricane in Minnesota. A typhoon in Guangdong. Drought in the Amazon. All because of a butterfly taking flight. This is what people call the butterfly effect, and it encapsulates what the mathematical theory of chaos proposes: that in some systems, variations that initially seem totally negligible and arbitrary can become magnified to massive and complex degrees. That even the most minute of actions can cause the greatest of commotions. That even the flapping of a tiny butterfly's wings can have profound effects on the weather.

It's hard to imagine what kind of butterfly could have caused the explosion, and when exactly the universe began to take note of its flight. Could it have been mere minutes or hours before? Days? Months?

It could have been years. I wouldn't know. It's been twenty years since I left Nagogiri City. Amidst wishes of good luck from those I'd come to call friends, I boarded a train to Takamatsu Airport for my plane to Tokyo. I majored in Sociology in Tokyo University and breezed through college without much ceremony, except that I graduated summa cum laude.

My good English landed me job at a British insurance company in Shibuya, under their marketing research department. While the pay was more than substantial, the work was a bore. In the beginning I tried to resist the monotony by learning French and German, but as time wore on, even that became a routine. I drank scotch alone in bars, read novels, listened to music. Sometimes, there was mail from Nagogiri: the occasional postcard from Fuuko, asking me how I was. Notes from Yanagi, which I ignored pointedly. An invitation to her wedding to Hanabishi, which I declined politely. Sorry, I'm swamped with work. I wish you two the best.

I lived in this uninvolved, uncomplicated manner, until the head of my department was shot in his office the autumn I turned twenty-three. As his assistant, I had to keep things running while the police did their rounds. After two weeks of investigation, they apprehended the man who'd killed him: his lover, a young Scotsman from advertising. Before they wrapped up, the senior officer, a tired-looking man who reminded me of my grandfather, told me, "You're too talented to be wasting your time in this shithole. We need people like you working with the Keishicho."

The Keishicho – Tokyo's Metropolitan Police. Before that, I'd never even thought of entering the police force. Much as I hated to admit it, I missed fighting for a cause. My degree in Sociology could get me into law school, but working in some snub-nosed private firm didn't appeal to me at all. I saw no harm in it, so I applied for the April examinations of the Keishicho.

It was like crawling towards a sliver of light: my application had given me a new sense of anticipation. I scouted Tokyo for a new apartment. In January, I quit my job and moved out of Shibuya, into a one-bedroom flat near Kasumigaseki in Chiyoda, where the Keishicho held its headquarters. I hesitated for days before sending my new address to Yanagi. In response to the wedding photographs she had sent me months before, I wrote a swift apology for the delay and my congratulations, as well as: if you ever need to find me, I'll be at this address.

I hoped it betrayed none of my desire to see her again.

I answered ads looking for part-time copy editors, so I could have time to review my university notes and work out. In retrospect, I don't know why I prepared so diligently for the examinations, but it paid off: I went into fifteen months of prerequisite police training. I was twenty-four when I became a keisatsu.

Four years after that, the butterfly brought not a tempest, but a wave of good luck. For a year and a half, the Keishicho had been trying to crack down on the Tokyo-based sect of an international drug ring. The situation escalated to a point where the International Police saw it necessary to intervene. My knowledge of French and German became an asset to the force while we worked with Interpol, and within two months, we were able to detain most of the major players in the local drug ring. After that, my superior, Watanabe-sama – the same senior officer who'd told me to join the force – encouraged me to apply for an internship to Interpol. I was accepted, and worked at the headquarters in France for eleven months.

When I returned to the Keishicho, my superior had been promoted to the National Police Agency, the Keisatsucho. I felt a mild loss – Watanabe-sama had never been less than kind to any of us. In contrast, the man who succeeded him was an asshole who liked to yell at the women, particularly at a sad-eyed girl who entered the force a year after I did. For a time I had to man the same police box as her, and she told me about how she used to play the violin. We slept with each other every now and then. She was beautiful in bed.

Two years of uneventful work passed, and mine remained a measured existence. I had a steady income, without any dependents, and I had more than I needed to live comfortably in the one-bedroom I called home. The butterfly seemed at rest, and for a while I was content to let it stay that way.

But that was beyond my control. The ripples of change resumed their course when a postcard found its way into my mailbox. In the last letter Yanagi had written, more than five years ago, she'd enclosed a photograph of their newborn Sakura, along with a lengthy account of her new role as mother. But the note on the new postcard was concise – almost obligatory. I'm so sorry to have not written sooner! I hope you're doing well. We miss you. Visit whenever you can, all scrawled on the back of a picture of the amusement park at night. I hadn't thought of Yanagi in years, and for the first time in so long, a familiar regret gripped my stomach.

The next day, I received more mail at work: in my e-mail was an invitation from Watanabe-sama's office in the Security Bureau of the Keisatsucho, to become part of his advising pool. And just like that, I was packing for the building beside the Keishicho headquarters. I treated the girl who played violin to dinner the night before I left, and she kissed me in the cab when I dropped her off.

It's been six years since. I never saw her again after that. I wonder if she still plays the violin: perhaps not. Too much has changed for everyone; too many butterflies traversing the skies. In time, they will have to land. They too must slow.

Or perhaps it was I whose gait had to be broken. The even pace at which I'd run my life came to a standstill this morning, the moment my assistant knocked on my door.

"Yes, Yoshida-kun, what is it?"

I look up. He is hovering in the doorway, pale and trembling. "Mikagami-sama," he begins weakly, "there's someone on the phone for you. It's from the Shikoku Regional Police."

I raise an eyebrow at him – what is he so distressed about? I speak to them all the time. He braces himself against the doorjamb as I put Shikoku on loudspeaker.

"Hello?" It sounds as if the deluge had come to Shikoku. Yoshida and I listen to the phone being passed from one person to the next. I stare at my assistant. His face is unreadable.

"Mikagami-sama," says a fearful voice, after a minute. "Hello?"

"Finally. What the hell is going on there?" I press firmly.

The young man on the other end swallows audibly. "Sir, we don't know what to do. No one saw it coming. We – my God. It's unbelievable."

I feel an inexplicable surge of panic. "What are you talking about?"

Initially… negligible and arbitrary. Magnified… massive and complex. I can't help thinking this is the most massive and complex a butterfly's flight can become. In five minutes Yoshida will have finished acting upon the first few of my orders: he will have forwarded the news to all the higher-ups. He will have started on the plans for the forces and aid that must be dispatched to the area. In ten minutes, he will have booked the soonest flight to Takamatsu, and arranged for lodgings.

But in these slow moments, as the young man in Shikoku measures his words, there are too many butterflies chasing each other in my head. I am at a loss for what to do.

"Nagogiri, Sir. Half the high school, and even the square beyond it." The young man pauses, as if for emphasis.

"What happened?" In mere seconds, the tragedies will turn.

He clears his throat. "Sir, they've been… Blown to pieces. They're completely destroyed."

Some notes on the research: I had to re-watch the first few episodes of the anime to catch Kurei say "Nagogiri City" - and of course, it does not exist anywhere. So while "Nagogiri City" is legitimately canon, it being in Kagawa, Shikoku is not. ;)

It's a very different style and genre from what I'm used to, and even a different pairing (to be honest, I needed a break from writing ToFuu). And though it's a little daunting (especially in this initial stage) I'm glad to be trying something new. I'd love to know what you think, though.

Thank you for reading, and I hope to see you in the next chapter. :) Till then!