Summary: Haibara tests a prototype antidode on Conan and herself. Seemingly...it works...that is until Shinichi wakes up and starts acting strangely...

Note: The pairing is Shinichi x Shiho. This chapter is rated T, but future chapters may be rated M.

"Woah woah woah...what did you just say?" The jaw of a certain shrunken detective fell open at the sudden news the girl in front of him had just unveiled. She rolled her eyes, finding it annoying that she had to repeat herself.

"I said I need to test this prototype antidote on you." The girl repeated with an impatient sigh. Her words instantly caused Conan's eyes to widen in clear bewilderment.

"Is there a chance it will actually work?! Like, permanently?!"

"Who knows?" Ai's vague response only made the detective more eager. An eager grin spread across his face.

"Okay, ready!" The boy quickly responded, staring at her intently. Ai couldn't help but smile a little at how excited he always got in these situations. Shinichi was usually the type who didn't care much about anything, hence his laid-back attitude towards everything. When the topic in question involved the antidote, however, his attitude would take an instant 180 spin. She held out her hand to him, the pill in her palm.

Conan observed the pill with obvious exhilaration. When a sudden realization came to him, however, he glanced at Haibara, eyebrow raised.

"Hey...Why don't you take it, as well?" He suddenly suggested, catching her by surprise.

"Huh?" Now Ai was the one in shock. "What are you saying, Kudo-kun? Why would I need to take it? You taking it will provide sufficient data."

"Come on, you don't mean to tell me that you don't feel any want to return to your original body as well, even if it's just for a short period of time?"

Ai stared at him with uncertainty. "Kudo-kun, I don't know where this is coming from, but I can't. If I took it and it failed, we'd both be in danger. There'd be no one to help us." She reminded the naive boy.

"And if it were to be successful...we could be ourselves again!" Conan chirped, eager to be in his teenage body again. "Besides, you are forgetting that the Professor is here too, in case anything goes wrong. He is a scientist, too, you know."

"That's not the point..." Haibara retorted with a frown. "He doesn't know anything about APTX-4869. Not to mention, imagine the consequences if a member of the organization saw our faces. Kudo Shinichi is supposed to be dead and Shiho Miyano is wanted dead."

After a brief moment of hesitation, the boy responded. "They shouldn't be too close by. After all, we have done a decent job at hiding and trying to lead them astray from our actual location...and it's not like we have to leave this house. You really need to let loose and take a break from all of this worrying, Haibara." Conan persisted in convincing the scientist to take the pill with him.

Of course, there's no way he'd reveal his true intention of why he was so eager. The reason was far too embarrassing.

"No." Ai coldly huffed out. "There are too many risks. I'd much rather be safe than sorry."

"Please!" Conan pleaded. He was really getting on her nerves. Why in the world was he so determined to get her to take the pill with him?

"It doesn't matter how many times you beg me. The answer will always be—"

"It'll be fun!" He assured with a grin. 'And what kind of fun would that be?' The girl thought jokingly, since his words sounded like an innuendo. Though, knowing how dense and "innocent" the guy was, she was sure his intentions weren't perverted.

"Ugh, fine!" Ai snapped. She had enough of his pestering. Though, she couldn't help but wonder what compelled her to even consider it? If only she hadn't given in.

"If anything bad happens, it's your fault." Ai hissed, clearly not wanting to do this. Maybe if they remained inside the house like he suggested, it would be safe.

"Yeah, yeah."

"Don't get your hopes up that it'll actually work." Conan didn't seem to pay much attention to her warning as he scurried to the bathroom downstairs and plopped the prototype pill into his mouth. A few moments passed by without anything special happening. Just when Conan was about to lose all heart, a familiar stinging pain shot through his body. He gripped his chest in pain, a loud scream of pain escaping from his lips.

'Geez...' Ai thought to herself, watching as the seemingly 7 year old child bolted out of the room with her hands placed firmly on her hips. She herself went off to the upstairs bathroom and took the pill. Not too long after this event, the pained screaming of both Conan and Ai reverberated throughout Agasa's house.

When the pain had finally subsided, the now 18 year old woman stood up, observing herself in the mirror. 'Looks like it worked.' The scientist glanced at her watch. 'Now...let's just see how long it will last this time. Hopefully I can gather some useful data from this experiment.'

Shiho threw on a lab coat over her red tank top as she made her way towards the main room, waiting for Shinichi. Nothing but silence was present until the creaking of the bathroom door filled the room. Shiho's eyes trailed towards the source, landing on the now teenage man standing before her.

"Looks like no problems occurred on your end, either." She commented as she started to walk closer him, preparing to observe the detective for any possible side effects. However, after seeing the strange expression on Shinichi's face, she immediately stopped in her tracks. She also noticed that his clothes were poorly put on, as if rushed. His chest was half exposed and his hair was all shaggy, almost as if he had just awoken from a deep slumber. It were as if he was in some sort of daze, glazed eyes scanning her up and down. Had she spoken too soon?

"Er...Kudo-kun? What's wrong?" Shiho asked worriedly, approaching him slowly with caution. Had her antidote failed? Did he somehow lose his memory or something? What went wrong? She knew this was all a bad idea. If only she listened to her instincts.

His blank expression suddenly transfixed into one of yearning as a sinister smirk crawled upon his features, much to the scientist's confusion. He took a few steps towards her, causing her to stagger backwards. This resulted in her stumbling and landing onto the couch behind her. Shinichi intentionally fell with her, now towering over the woman. His slender arms held her down so that her movement was restricted.

Shiho couldn't control the heat that suddenly consumed her cheeks. Their faces were mere inches apart. It certainly didn't help that his toned chest was pressed against hers, making her heart race faster with every second. She could hear his steady breaths as he loomed over her. They had these unintentional interactions before...so why was she feeling so different, now? Why was she so flustered? Maybe it was because he was no longer a child? After all, he was very attractive. Not that she'd ever admit that to him. No way in hell.

Now that she thought about it, this was the first time they were in their original bodies at the same time together. Usually, one of them would have taken the antidote while the other would still be in child form, so it was quite unfamiliar. She was used to being the same height as him as children, so she wasn't accustomed to having to look up to him since he was a few inches taller than her.

Shiho realized she had been holding in her breath for a while. When her senses came back, she gave Shinichi a light push, trying to get the teen off of her. Her attempt was futile, however, as the detective in question had her pinned down with ease. She didn't miss the lustful glint in his eyes as he then proceeded to remove her lab coat. When Shiho realized what he was trying to do, she became increasingly nervous as her hand quickly clenched his arm, ceasing his action.

"K–Kudo-kun, just what are you doing? Get off of me." She had known Shinichi for a nearly a year, now, so she was sure that he was not this much of a pervert. There's no way that he'd would ever so much as attempt something like this. Knowing this, Shiho came to the conclusion that there was something in the prototype causing him to act this way. What she didn't know was what it was and why.

'Besides...he has Ran, not me.' She thought somewhat bitterly as she continued her pointless struggles to free herself from his hold.

"You know...you're very cute, especially when you blush like that." He purred seductively as he moved even closer to her, his hand caressing her face. To say Shiho was in shock would be a severe understatement. Shiho's face turned a deeper shade of red, unable to tear her eyes away from his.

'Okay...Kudo would never say something like that. Especially not to me. What the hell is going on?' Just as her thoughts swarmed her mind, she felt a sudden warmth on her face as Shinichi nearly closed the distance between them, his lips lightly brushing against her cheek. All Shiho could hear was the intense pounding of her heart as he moved towards her mouth, his touch and steady breathes sending shivers throughout the nerves of her entire body. She could only lay still, frozen in time as the world around her no longer mattered.

When he finally presses his lips against her mouth, everything goes oddly quiet. At first, Shiho tried to push him away again..but then she soon found herself giving in, melting into the kiss. It quickly turned into an intensely passionate one as they fiercely battled each other with their tongues. Despite it being her first, kissing him felt completely naturally to her.

'Kudo...and I... we're actually...' Her thoughts were a jumble as she still could barely process what was happening right now. Even if the detective in front of her wasn't exactly himself at the moment, she had to admit she was enjoying this. They were so close that she could practically feel his intense craving for her, as she could feel desires of her own starting to surface. It was nothing like she had ever experienced before.

"Mmmmm...S-Stop..." Shiho breathed out through her small moans. Shinichi showed no signs of stopping, however. In fact, he only pressed up against her, rougher than before, causing her entire body to grow even more warm. He then reached for the brim of her tank top, preparing to remove it. At this point, Shiho lost all of her judgement. All she could focus on was Shinichi. Her hands uncontrollably reached to take off his half-put-on shirt, as well. She had never wanted anyone so badly before.

"OI, CONAN! WE'RE HERE!" Suddenly, the front door slammed open. Three children stood, searching for their friend. Their eyes fall on the two figures making out on the main room's couch.

'What are those kids doing here?' Shiho thought to herself as Shinichi finally broke the long kiss, pausing. They both gasped for air. His eyes then fell on the trio, a clear glint of irritation present in them.

"Oh...uh, sorry...we didn't mean to interrupt..." Mitsuhiko apologized, a blush forming on his face, along with Ayumi and Genta's.

"W-Wait a minute, aren't you Ran-san's boyfriend?" Ayumi realized, recognizing Shinichi's face from before.

"What?! So he's having an affair with another woman?!" Mitsuhiko gasped, astonished.

Shinichi's threatening gaze only intensified, sending shivers down their spines. This action seemed to shut them right up as they slowly took a few steps backwards.

"U-Uh, we won't tell!" Genta squeaked in fear as he bolted out the door, along with Ayumi and Mitsuhiko. Shinichi turned back to the still panting woman beneath him.

"Now, where were we?" His low voice was so...how should Shiho put it...hot...that it made it difficult for her to control herself. Half of her wanted so badly to kick him off and escape...yet the other half wanted for him so badly to continue.

The former shrunken teenager then made his way downwards, leaving trails of small kisses and hickeys along her neck, tickling her. A chain of giggles left her lips at every kiss, feeling pure bliss. His warm tongue on her skin sent shivers of pleasure throughout her core. He continued to move downwards, now nearing her almost exposed chest. With that same intense lust in his eyes, he tore off her shirt, leaving her entire upper half in the nude.

Shiho watched with embarrasment as Shinichi admired her body for a moment.

"Beautiful." He commented as he then made his way for yet another kiss. Shiho's hands wrapped around the back of his neck as she found herself sliding off his shirt as well. Now it was her turn to observe his muscular body.

'Wow, I didn't think he was so well-built.' The scientist couldn't help but think to herself, her eyes scanning his body in both surprise and awe.

Shinichi chuckled at her reaction, causing her to quickly tear her eyes away from his body in embarrassment. "Like what you see?" His seductive voice alone made it extremely difficult to even think. She never thought she'd ever see this side of Shinichi before. Well, she didn't even know he had this side to him.

"All I see is a know-it-all narcissist." She retorted, red-faced. She found herself unable to make eye-contact with him all of a sudden. A small sensation on her chin caused her eyes to widen in surprise. Shinichi's fingers had gripped her chin, forcing her head to turn in his direction. Once again, Shinichi leaned in for yet another kiss, their bare chests both pressed up against each other. Shinichi's hands slowly made it's way to her pants.

It was at this moment that Shiho realized they needed to stop. If she didn't stop this, who knows what what happen? They were already taking it a few steps too far.

Shiho moved away from him, breaking the kiss. "Kudo-kun...please, that's enough." The woman tried once again, to no avail, however, as Shinichi moved in for more. She tried to push him off again, only to be forced back down. 'Damn it...Professor, where are you? If this continues...'

Suddenly, the front door opened once again, much to Shinichi's disappointment. He was even more annoyed now that he was interrupted not once, but twice.

He turned around, ready to scare off whoever it was. Much to his shock, however, it had been an all too familiar figure.

'It's...him!' Shiho recognized the figure to be Subaru Okiya. This was her chance.

The man who had just entered the room was currently holding a pot of food, showing that he was dropping it off. He only stared at the two in clear confusion.

"I apologize for interrupting you and your girlfriend, but do you happen to know where the Professor is?" Subaru queried in a somewhat teasing manner.

"H–Help me! Get Kudo-kun off of me, please!" Shiho ordered Subaru. Without much thought, Subaru was near them in a flash. He pulled Shinichi off with ease, now holding him in a lock. Shinichi struggled, failing miserably. Subaru was much stronger than him. He had years more experience than him, after all. As soon as Shinichi was pulled off of her, she quickly covered her exposed chest with a pillow.

"Let me go." Shinichi demanded, scowling. Subaru ignored his request and glanced at the relieved Shiho, raising an eyebrow.

"Care to explain what's going on?" Subaru, or Akai, asked, his single green eye opening. Shiho sighed.

"I tested a prototype antidote on ourselves...and this happened." She gestured towards the struggling teenager before her. Of course, Akai had already known who the two were, for a while now. He just found amusement in messing with the two children. Now, he had to be serious, however.

"I see...perhaps there was something in the prototype that boosted hormonal activity...In other words, he must be–"

"Please, don't finish that sentence. I get it." Shiho quickly barked back, annoyed at this whole situation. "I just don't understand why it didn't affect me, either."

Akai shrugged in response. "Perhaps it only affects males?" The Professor chose this moment to just wake up. His thunderous footsteps filled the room as he came down the stairs. The elder's eyes first fell on the amused Akai, then drifted towards the pissed off detective, and finally to the exhausted and half-naked scientist.

"Huh, what's going on?" Shiho was about to explain to the Professor when both she and Shinichi felt the familiar pain strike their bodies. Subaru let go of the boy, letting him run off to the bathroom. Shiho hurriedly left, as well, not wanting to change back in front of them.

Not too long after, the two walked back into the room, now in their bodies and fully clothed.

"Huh...did the antidote work? What happened?" The re-shrunken boy appeared completely oblivious.

'Great...' Shiho thought. 'He doesn't even remember what happened.'

"It's best if you don't know..."