A/N Apologies if this is so OOC! I wrote this in a rush because I got so excited: CoAi Week will be held soon! Go to this blog for more details coai-week . tumblr . com. Fanfics, fanart, edits, mad, mood boards, fave (coai) manga chapter, fave (coai) episode, fave (coai) moment, fave (coai) song, fave (coai) headcanon, an AU you'd love to see, or even just a retelling of how you got into coai—I hope I get to read these from everyone who still ships (submarines? XD) coai!

Edogawa Conan—that is, Kudo Shinichi—enters the professor's house, cautiously, quietly. He looks around. Nothing out of order.

"Shinichi!"

He nearly jumps out of his skin. He thinks in retrospect that he shouldn't feel like a burglar caught in the act, but he's far too relieved that the professor is here and alive and he's the person that greeted him to dwell.

"What a surprise! What brings you here so suddenly? A case?"

He rushes past and checks the rooms, one-by-one. Nothing out of order. He supposes he should trust the agents watching the house, but...

"Shinichi-kun, is it them?"

The detective turns around and finally looks at the professor. He's worried, deep crease lines on his forehead even more apparent now than when he had welcomed him, but Shinichi feels too unsettled to feel bad about the tension.

"Has anything happened? No one went in here?" the detective asks.

"Here? Nothing out of the ordinary."

"Has... Haibara told you anything?"

The professor's eyes bug, and his voice gets a little more frantic, asking, "Is this about Ai-kun? What is it?"

"No, nothing..."

"Shinichi, if it's them, I—"

"No, professor, I might have just caught that woman's paranoia... ugh."

"...If you say it's nothing, Shinichi-kun..."

"I'll go talk to her. Thanks, professor!"

"Shinichi-kun, she's at the lab. Ask her if she needs anything for breakfast would you?"

"I know, and sure thing!"

—

Shinichi mulls over the details of this... case... as he makes his way to the lab.

Point one: two days ago, Haibara sent him a message, "Come visit the professor once in a while without a case in tow lol he misses you Ci"

A cut-off message. Haibara's a stickler for grammar and typos, but maybe the late nights probably caught up to her, is what he thought. After a few hours, that same day, he receives a message from her again, this time, "I'll tell the kids you're sick Ci"

He told himself then that it's probably a stupid trend she'd picked up from Higo, like Yoko's song.

Point two: yesterday, he overhears the kids talking about Haibara being on her phone more than usual. He asks them if she sent them a message yesterday that's different than usual, and their blank faces told him all he needed to know. He didn't appreciate being bugged about what Haibara sent him though, but he did tell them the truth—it was harmless enough, the professor missing him.

It was probably nothing, since none of the agents around were reporting anything out of the norm, he thought.

Point three: last night, when he asked her to cover for him for the coming kids' trip, she replied, "Lol no. But I was just checking Prada overcoats... Ci"

He asked her point-blank, "I'll get you the cheapest one, woman. What's that 'Ci' anyway?"

His eyebrow might have shot through the roof then, since he can just imagine her face with her reply, "And you call yourself a detective? Lmao Ci"

Of course, he firmly believes that her last reply is not the main reason he's itching to break her code. Just thinking about it put a scowl on his face though.

Now, onto the possibilities. It is highly likely that "Ci" is a shortened form of something.

Possibility one: Ciao. She does use them at the end of her messages, so it may be the trend right now. But the kids didn't see anything weird with her messages to them, so she might not have been sending it to them—and the kids would have been excited to tell him about something new they learned—nor does he receive anything like it from Ran. Besides, with her jab at being a detective... she might be saying goodbye to him, but there isn't anything to suggest she'd leave...

Possibility two: C.I. Counterintelligence—a spy? Confidential informant—a double agent? Certificate of identity—someone else knows about us? Or has she figured out... No. Surely Akai-san would have noticed and would have said tipped me off.

Possibility three: C... I...

He chases possibility three away. It's impossible. Just impossible.

Small steps slowly lead him to the lab. He turns the knob, opens the door and steps inside.

—

He enters the lab, and sees the scientist, Haibara Ai, on her computer. Eyes scrunched up, left hand on her head, right hand balled into a fist. The screen shows her wallpaper, a picture of the kids and the professor.

Suddenly, possibility four strikes him—is she sick?

"Oi," he starts.

She opens her eyes, bright against the bags under them. She's pale, and her glassy gaze adds to his worries.

"Are you okay?"

"No."

"You're sick?"

"Of dead ends, yes. I'm just... tired, nothing to worry about. But you better not have something for me to check because I will not do it."

If she isn't sick, then... "Ah, no, nothing of the sort. Just, has anything happened..?"

"Excuse me?"

"Any new information you'd like to share..?"

"Excuse me?!"

Judging by her reaction, the detective crosses out possibility two.

Still, the scientist, peeved, continues, "This is about the antidote isn't it?" She straightens her posture and flatly recites, "I am trying my best, as I have from the start. I deeply apologize for my incompetence and would like to wish for more time, since time is our ally in producing results."

Narrowing her eyes dangerously at the boy in front of her, she continues, "What's next now, detective, want to act as my supervisor and ask me for daily reports? Guilt-tripping me this way, at this time, is very unbecoming, Kudo Shinichi-kun."

If her eyes were blades, he would have been pinned to his seat. She further explains, tone raising, "You know I'm not giving you the temporary antidote for our safety, but it's for your safety mostly! It's a prototype, and you could die. Your genius mind can't seem to handle that simple fact even after a litany—"

It would have been the lecture she thought he needed to hear again, but unfortunately, he wasn't listening.

"Haibara," he interrupts.

"No, Edogawa-kun, you listen—"

"Wait, no, stop, it's not about the antidote, it's just... I broke your code."

"My code?" she's still irritated, but the all-nighter takes its toll on her, and the tension in her small body gradually dissipates. It leaves her with confusion and exasperation.

"Well, no, uhh..." he's rarely hesitant and they both know it. She's intrigued now. But still irritated.

He clears his throat, "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."

He continues, "See, I thought that 'Ci' was a typo at first, then I thought it stood for something, perhaps about an informant or new information?"

"Quite embarrassing but I even thought you were about to leave but, I just checked the rooms, and your things are still there," he says.

"And, so, the only possibility remaining is, 'Ci' is a signature. To be exact, it's your signature. C-I. Miyano Shiho, Haibara Ai. Shi-Ai," he concludes.

He notes, "And since the kids and the professor don't seem to notice, looks like you've been sending your signature only to me..."

"So, uhh," and he mentally beats himself up because he knows she'll tease him—he can feel his face burn!—but he can't help it. He clears his throat again, "Shih— Ai. Ai, I cracked your code."

He tries to give a smug smile, but it comes out twisted and awkward. She would have laughed at how red his face was had she not been frozen—in embarrassment for him, she'd think later, but right now she can't really think either.

She's confused—is this the effect of a sleep deprivation? She doesn't really know whether she likes this or not.

"S-so, yeah," he forces a laugh, "you didn't have to be so weird and create a code! Just, you know, ask me to call you by name. We are partners, you know... A-Ai." Another awkward laugh.

His awkward laugh, his cheeks that are reddening even more, the absurdity of it all, snaps her back into reality and she's painfully aware that this is all too real. She's too shocked to laugh. She probably doesn't feel her face turning the same color as his.

It takes her a few more seconds to get over it. Pretty—and funny, in retrospect—as it is, it's time to pop the bubble. She tells him, "Kudo-kun, 'Ci' is a wink smiley."

His awkward smile looked even more comical with his eyes wide open. He looked like he could combust any moment—to be fair, both of them looked like they could spontaneously combust.

She breaks the silence, "But, well, uhh, maybe, as long as you get me coffee, I... don't really mind..?"

"S-sorry!?" His eyes turn into saucers.

She turns away, too quickly, "J-just kidding. Nevermind. It's... fatigue talking."

"..."

"..."

"Uhh... okay, I'll go get you coffee then, uhh, Ai."

"..."

"..."

A/N Hugs and kudos (and pancakes!) to whoever knew what Ci is from the start! XD