A/N: It's somewhat of a running joke now that you can tell I'm really crazy about a fandom when I start writing in it. It's like the final giant red warning flag. But ha! You've been outsmarted. Way down in my profile you'll find a few other, extremely old, probably poorly-written (omg fangirl Japanese EVERYWHERE! x.x) bits of fiction from my last dip in the Detective Conan pool. Thus, I can pretend that these are just old plotbunnies coming back for a second haunting!

However, things have changed since I last wrote Conan stories, things that incite reviews such as "lol i jus love rachel with jimmy they r soooooooo sweet!1 i cant wait 4 them 2 get 2gether!11eleven". The names alone were enough to keep me as far away from the dub as possible. So, this fic is written using Japanese terms, and I hope NOT to receieve comments this time "correcting" my terminology. Ha ha. (This note was actually merited by a few reviews on my older pieces and a friend's, one of which said 'who's shinichi?' and another of which was something like 'good fic but u got the names wrong its jimmy and rachel') You're talking to someone who bought the Case Closed manga the day it came out, read two pages, and then took a bottle of Wite-Out to the entire book to repair the atrocities. So please don't ask me to change the names, and if you don't know who's who, consult Wikipedia.

With that said, please enjoy the fic!

Only This

by Shimegami-chan

-A/N: Heiji refers to both Ran and Haibara as 'Neechan. Context should tell you which is which.-

The pairing will be Ran x Conan/Shinichi.

It began as any other Sunday; lazy and slow, the members of the household eating a late lunch and enjoying a break as the phone sat quietly on the desk in the Mouri Detective Agency. Lately there had been cases every day, sometimes two a day, faster than they could be fully investigated and filling the answering machine with messages whenever they left the office. It was winter once again and both Mouri Ran and Edogawa Conan were on the last few days of their vacations from school. Even Ran, who was usually such an early riser, had woken up well past eleven on this particular January morning.

Conan was stretched out on the couch before and after a light lunch, pleading dizziness, and Ran was mothering him obediently. It was rare to see the boy so listless, even early in the morning, and she was just a little bit concerned. He'd seemed lethargic lately as well, and wasn't eating as much, symptoms Ran had chaulked up to the winter blues, but they were so out of character for Conan that she couldn't help but worry. He would often stop even while walking short distances and need to catch his breath, and unconsciously leaned against walls and furniture for support around the house. She wondered if it mightn't be something so serious that it was worth calling his parents and asking about medical history. Conan was so secretive sometimes that she knew little about him, especially in this kind of situation, where the most knowledge she could boast was his blood type because he shared the same as her and Shinichi.

He'd been hospitalized a dozen times, of course, because Conan had a habit of getting into trouble and injuring himself. He was rarely sick, though, and as his current condition began to linger, Ran wondered if it mightn't be something serious. Conan waved her off, saying "It's no big deal, I'm just tired, that's all."

So tired that he'd hardly moved from the couch at all on that particular Sunday, even to come to the table for lunch. Kogorou had just left to play Mahjong and Ran was busying herself with the cleaning in the bathroom when she heard his plaintive voice from the office, raspy and a little distressed. "Ran-neechan?"

"Yes?" Ran stood and wiped her hands on a towel, wondering at the strange tone of his voice. "I'm in here."

"I think I need...an ambulance."

She was out of the bathroom and by his side in an instant. "Conan-kun! What's wrong! Are you okay!"

His eyes were squeezed shut and he was breathing in gasps, clutching his chest with one hand and trying to use the other to prop himself up in a sitting position. His white collared shirt was soaked through with cold sweat, and he shivered violently. "My...chest..."

"I'll call!" Ran promised, and threw a blanket around his shoulders before running to the phone and dialing 110. She explained to the operator that she needed an ambulance as quickly as possible and gave them the address, gathering up her purse and coat with her back turned to the small boy, and when she turned around again he was laying utterly still, one arm slack and hanging over the edge of the couch.

She dropped the phone.

Hours that seemed like days had passed for Ran in the hospital waiting room, as she tried to read the magazines scattered about, and found that no matter how many times her eyes scanned each page, she couldn't remember a word of what she'd just read. She wished her father or Sonoko were here to help her, but she couldn't contact either of them. Shinichi wasn't answering her calls or e-mails at all. She'd even e-mailed Kazuha, without reply, before being forced to sit quietly and hope that there'd be news soon.

When she'd seen Conan, lying unconscious like that, she'd been sure he was already dead. At first he hadn't even moved, but sweat still poured off his tiny body and he began to shake uncontrollably, as if he were possessed. It was all she could do to bundle him up tightly and carry him downstairs to wait for the ambulance, barely conscious of her keys in the door, the phone in her pocket.

The ambulance attendants were stumped. He was having some kind of reaction, they thought, but it didn't seem to be allergies, and as far as Ran knew he'd never had heart problems. The symptoms he was displaying were similar, though not quite a perfect match, for a heart attack.

Heart attack? He's only six years old! Ran thought desperately. No, it must be something else, something else...

But what?

Eventually she'd been called in and the situation explained to her in place of the absent Edogawa Fumiyo, Conan's mother. But even after dozens of tests and monitoring, the doctors simply could not find an explanation for the attack. They'd identified a number of abnormalities in his body, most importantly the way his cells seemed to be turning on themselves...but no one had ever heard of such a condition. It was simply destroying his body from the inside out.

"But what does that mean?" Ran had cried desperately. "Can't you stop it? He's going to be all right, isn't he?"

"We're doing our best," the doctor had said gravely.

He was stable, so they let her in to see him, and the sight took her breath away. Conan was hooked up to a dozen machines, from heart monitor to oxygen mask, and he seemed so small and frail among the mess that she was stunned. He looked peaceful underneath all the tubes and wires that were keeping him going, wearing a thin blue nightshirt, his glasses and clothes were folded up neatly and placed on the storage cabinet. He was fast asleep, or drugged, or both.

He was unconscious for more than three days. Ran slept, bathed and ate at the hospital, passing her days reading aloud to him, everything from her favourite romance novels to Holmes, thinking to stir him into consciousness. The Detective Boys appeared intermittently, and Professor Agasa came often with Haibara Ai, coaxing Ran out of the room to get fresh air whenever he could. Haibara sat alone in the room with Conan when Ran was out, intently taking note of the equipment that surrounded him.

On the third day Hattori Heiji arrived from Osaka, carrying a duffel with enough supplies to keep him in Tokyo for a week. Haibara was guarding the patient when the Western detective arrived with a sombre face. "Hey there, 'Neechan."

Haibara regarded him coolly. "I thought you might show up. Kudo-kun isn't looking so great." The young scientist seated herself in the chair beside the hospital bed.

Heiji sat in the other chair and took off his baseball cap, placing it on the bedside table. "Has he woken up at all?"

"Just once." Haibara paused. "Yesterday afternoon, when he asked for you."

"Me? Huh, I guess that explains why 'Neechan e-mailed me." He patted the cell phone in his jacket pocket. "She only said that he was sick at this hospital, though. If I'd known it was bad I would have been on the next train."

Haibara shrugged.

"Well, do they know what it is?"

"'They' don't know," she replied. "All they can do is observe him until they find the problem. Which they won't."

The detective was dumbfounded. "Why? Do you know something they don't?"

She looked at the unconscious boy. "It's the apotoxin."

"What...?" Heiji stared at her incredulously. "That shrinking poison? You mean like a side effect?"

Haibara shrugged again. "I wouldn't call it a 'side effect'. I can't exactly analyze it like this, but Kudo-kun is showing the same syptoms, albeit very slowly, that he would have exhibited had the poison originally done its work. It's multiplying key cells in his body, suffocating him from the inside out."

"But isn't there something you can do?"

"What do you think I've been doing when I'm not here?" she shot back icily. "I'm working on it. If I had a cure I would have given it to him long ago."

Heiji's dark face had turned very pale. "Are you saying that he's going to die of this eventually?"

"Not eventually," Haibara corrected. "Soon, unless something's done. The Professor and I have been awake for three days now, working all night, and the best we've been able to do is alter the temporary antidote, which is still unstable. In his condition, I don't dare even give him that. Plus, we can't test anything, so there's no way to say for sure if anything will even work."

Swallowing hard, the detective turned his face away from the unconscious patient. "Do you know how long he has?"

"No. I can only judge based on the instruments in this room that it's progressing much more slowly that the drug was designed to, but much faster than it was a few days ago. They're only giving limited information on his condition to the Professor, and the Mouris are trying to keep the kids from finding out, myself included."

"And 'Neechan is...?"

"The Professor has been coming in and making sure she's eating while I take notes. In fact..." Haibara inclined her head at the sound of approaching footsteps. "I believe they're back now." She stood, regarding Heiji with a calculated stare, and frowned. "I'll be taking this information to the lab, so I'll leave Kudo-kun to you. Try not to let that girl know how serious this is. Goodbye, Hattori-kun."

Heiji watched Ai leave the room, a little taken aback at her abruptness. A cluster of voices began speaking in the hall, and a moment later Ran entered wearing a worried smile. "Oh, Hattori-kun, you came."

"Of course," Heiji replied, trying to look as confident as possible. A strange feeling had begun to churn in his stomach, making him feel as though he wanted to run right out of the hospital and never come back. Kudo, dying? It can't be. I'm sure there's something that 'Neechan and the Professor can do for him, right?

Ran had been speaking, and Heiji had accidentally tuned her out. "...they say he's stable now, though they still don't know what the problem is! His parents are even thinking about flying back here from America to see him. Poor Conan-kun!"

Hearing that name was like a punch to the gut. Damn, he's going to kick the bucket, and he STILL hasn't told her? Well, I guess he really can't, now, if he's sleeping all the time. I wish I'd asked that girl whether she thought Kudo would wake up again...what if he never does?

"I was really worried," Ran was admitting, "but he seems so much better now. When he woke up yesterday he asked for you, Hattori-kun, so I hope you didn't mind making the trip."

"Oh, of course not," Heiji's mouth said on autopilot. Should I tell her, just in case? Kudo will be mad, but maybe she can help bring him out of it. There's nothing like your lover's voice to keep you going, or something like that. Besides...even if he wakes up he'll probably be so drugged he won't know what to say... Heiji frowned. It doesn't sit right with me, knowing what's gonna happen to him and still keeping her in the dark. "Hey, you know...why don't you sit down? You and me should talk awhile."

"Sure," Ran agreed. "It'll be nice to have some company." She sat in the chair Ai had vacated, and Heiji moved his seat around so he was facing her.

He glanced to his right, where Conan lay sleeping, his small face enveloped by the oxygen mask. "'Neechan...it's not my place to say this...but there's something you need to know about K...Conan. I've been trying to get him to tell you for a long time, because it's really important to him, but it looks like now he might not get the chance."

Ran paled. "Come on now, don't overreact. I already told you he's been getting better! He can tell me when he wakes up...if it's so important that he do it himself.."

"You don't understand," Heiji said with a frown. "Those doctors don't really know what's wrong with him. It could be something...really bad. Something he mightn't wake up from!"

"Don't talk like that!" she snapped, and Heiji was taken aback by her harsh tone. "What's the point in getting depressed about it? They'll find the problem and cure it soon enough! It's not like you to say such things, Hattori-kun. I know you and Conan-kun get along well, so you'd think you might act a little less fatalistic! He's going to be fine!" She leapt to her feet and stalked out of the room, her cheeks already wet with tears.

"Dammit, come back!" Heiji yelled at her retreating back. "I HAVE to tell you, in case he dies! That kid is really...he's really..."

An exasperated sigh. "-Really in a lot of pain right now."

The tone of the voice from behind him was nearly enough to stop Heiji's own breathing. He turned. "Kudo...you're awake! Ah! I'll call her back for you-!"

"Stop, Hattori. That's enough." Conan shook his head slowly, a grim smile on his childish features. One of his eyes was squinted closed and the other struggled to stay focused on the Western detective, who appeared to Conan to be rapidly multiplying.

Heiji grabbed the railing of the bed with his hands. "But if you die..."

"Yeah." Between laboured breaths, Conan forced his vision to clear long enough to lock eyes with his friend. "I'm going to die in this body. No one can find out what happened to Kudo Shinichi, not even Ran. You understand that..."

"No, I don't!" Heiji growled, slamming both hands down on the metal hard enough to rock the bed. "What would it hurt to tell just that girl? You know she'd keep your secret!"

"Idiot..." Conan lay back again, eyes closed. "Don't you think it's worse if she finds out, just before I die, that I was Shinichi all along? That's why I asked you...I wanted you to come here to do me a favour. You have to help me keep my secret."

Heiji inclined his head. "What kind of favour?"

Reaching under his pillow, Conan shuffled around for something and withdrew it, pushing the crumpled red item into Heiji's hand. "Use this...and tell her I've gone somewhere far away, overseas with my parents. I might not come back. I can't risk telling her, not like this...not when there's still a chance..." He paused before quoting something Heiji didn't recognize. "'Men have been as bad as this and yet recovered.' Shoulto; The Sign of the Four. But if I don't make it..." The tiny detective heaved a great sigh. "Your Standard speech is a bit troublesome...but I think you could do it, Hattori. Please."

"Now who's the idiot!" Heiji cried, but his fist closed tightly over the bow tie. "You want me to do that with a straight face, Kudo! You can't be serious!"

The smaller boy's eyes were hidden behind his messy bangs. "After all we've been through, no, maybe not with a straight face. But I'm serious...I'm asking you just this much. Only this. Please?"

Heiji sat absolutely still for a moment with his head lowered. Neither spoke for a long moment, until the Osaka detective opened his hand and looked at the red bow tie. "Fine. I'll do it, but don't think I agree with it!"

Both raised their heads and their eyes met, blue against blue. Conan's mouth opened slightly in surprise at Heiji's crumpled face. "Hey, there's no need to get worked up about it..."

"What's wrong with you!" Heiji exploded, his expression suddenly fierce. "Can't a guy be unhappy once in a while? Doesn't the great detective Kudo ever feel sadness!"

"Well, of course!" Conan put up his hands in a calming gesture. "I just didn't think you'd be so against it."

"Listen to you." His voice had dropped to a whisper. Heiji turned his head to the side and clenched a fist. "You're talking like you're already dead. You're resigned to this! I'm not upset because of what you're asking, I'm upset because I don't want you to die yet! Idiot!"

"Hattori..."

"I'm an idiot too." Heiji let out a strained laugh and drew the sleeve of his jacket across his face as though to wipe off the emotion itself. "I'm a detective...we're detectives. We see this all the time, right? Bodies, and...people we know, sometimes, leaving this world before their time. Someone's always shooting someone. But it's different with you, you know? I..."

Conan frowned deeply as Heiji paused to collect his thoughts. "I'm trying to be rational."

The Osakan boy nodded. "I know, I know. Just hear me out...if this is how it's going to be, then I want to say this while you're still here to listen. I thought I was a pretty hot detective...well...I guess I am. But I was cocky. That first time we met, all I could think about was how you were a rival because people compared us, you know? Even the second time, out at that Holmes convention thing...I went there looking for 'Kudo Shinichi.' I wanted to prove myself to you. And before I even knew you were him, you taught me a bit of humility. Looking back on that and everything that came after it..." He forced a wavery smile. "Yeah, I guess we're still rivals, but things always worked better when we were partners. I never really had a partner before, or even a friend who was into these things...I once thought, 'the more people you get close to, the more people you'll eventually have to deal with losing'."

"Hattori..."

"But it was...really great having a friend on the same level, I thought, after I got to know you." Heiji met Conan's gaze again, this time his expression controlled. "So I wanted to say thanks for calling on me when you needed help, because I know you would have done the same if it were me. Besides Kazuha, of course, you really are the best friend I've got."

At this Conan's own stony expression dissolved and he turned away. "Haha...it's because of that kind of speech that Ran can't know about this. But thanks for saying it, anyway."

-to be continued...

A/N: This was originally a one-shot, but when it topped four thousand words I had to start dividing it into chapters. Expect the next one soon.