Hey, so I'll cut to the chase. This has spoilers for one of the last scenes in The Disappearance of Haruhi Suzumiya. Other then that though, it could really take place at almost any point afterward. Beware! Also, I hope you'll forgive the odd writing style, particularly certain pronoun usage; I was attempting to illustrate Yuki's thought process, even if I was writing in 3rd person.
Uncertainty
The Integrated Data Sentient Entity humanoid interface Yuki Nagato was alone in its apartment.
Yuki Nagato was reading.
The concept of books always fascinated it. Humans had evolved sufficiently to use the internet, which contained a much larger cache of data than any book could, but the ability to tangibly hold human data in its hands served as an interesting parallel to Nagato's own ability to manipulate data that human beings simply considered to be their world. Furthermore, Nagato was unable to comprehend how such an archaic method of data transfer was still utilized by humans despite being obsolete. And yet, the humanoid interface found itself unable to condemn it, and, for some reason, could not quell its desire to read further.
However, its reading was quickly interrupted by an incoming transmission from the Integrated Data Sentient Entity itself.
SCANNING DIRECTIVES... DONE
PRIMARY DIRECTIVE: Observe Haruhi Suzumiya.
SECONDARY DIRECTIVE: Protect subject 'Kyon.'
Before any of its many other directives could be listed, the Integrated Data Sentient Entity made a change.
NEW SECONDARY DIRECTIVE: Terminate subject 'Kyon.'
The transmission was over, but Yuki Nagato did not move. The page was still in mid-turn, but the humanoid interface did not care. Terminate Kyon? Could it do that?
"Can you tell me if there are many others like you on this planet?"
"A lot."
"Does that mean there'll be those who might attack me like Asakura did?"
"I won't let them."
SYSTEM ERROR. RESETTING SYSTEM.
...
SCANNING DIRECTIVES... DONE
PRIMARY DIRECTIVE: Observe Haruhi Suzumiya.
SECONDARY DIRECTIVE: Terminate subject 'Kyon.'
Terminate Kyon.
Nagato rose to its feet. It was morning now. Yuki Nagato grabbed its bag, which already contained all of the necessary objects for school.
All except one, that is. Yuki Nagato grabbed its hunting knife. Nagato noted that it was the same kind that humanoid interface Ryoko Asakura used when it attempted to terminate Kyon.
There was no need to hurry. It would strike after the SOS Brigade adjourned for the day. All Nagato needed to do was request to speak to Kyon afterward. Interface Ryoko Asakura had used a similar strategy, but subject Kyon trusted interface Yuki Nagato. He would not suspect a thing.
"Does that mean there'll be those who might attack me like Asakura did?"
"I won't let them."
Yuki Nagato was on its way to school. While it walked, it was viewing its memories of subject Kyon. It was temporarily unsure why, but it determined that it was for informational purposes.
Yes... informational purposes.
"Drink it."
Subject Kyon complied.
"Is it good?"
"Y-yeah..."
School had begun.
"Nagato, we need to leave."
"..."
"Oh, do you want to check out that book?"
"Yes."
"...Do you have a library card?"
"No."
"Okay, here, I'll help you get one..."
It was lunch period.
YUKI.N I'm betting everything on you.
'Betting on me for what?'
YUKI.N I hope that you can both return to this world. Haruhi Suzumiya is an important observation target, an important treasure that might only appear once in this universe.
Besides that, I myself also wish for you to return.
...
YUKI.N Let us go to the library again next time.
School was over. Subject Mikuru Asahina entered the clubroom. Yuki Nagato sent a tranmission to the Integrated Data Sentient Entity.
QUERY: For what reason must subject Kyon be terminated?
INCOMING TRANSMISSION
RESPONSE: In order to observe the reaction of Haruhi Suzumiya.
SCANNING DIRECTIVES... DONE
PRIMARY DIRECTIVE: Observe Haruhi Suzumiya.
SECONDARY DIRECTIVE: Terminate subject 'Kyon.'
Mikuru Asahina finished changing. Subject Kyon entered the clubroom.
"Yo."
"Kyon."
"Yeah Nagato?"
Mikuru Asahina was busy making tea. She would not hear.
"I would like to speak with you after the meeting."
Kyon displayed the emotion of surprise. "Is something wrong? Something about Haruhi?"
"No, it is-"
"Does that mean there'll be those who might attack me like Asakura did?"
"I won't let them."
...
YUKI.N Let us go to the library again next time.
...
"Nagato? You just stopped talking there. Is something wrong?"
"No, it is for... a different reason."
Kyon nodded. "Okay, then."
Subject Haruhi Suzumiya entered. Yuki Nagato attempted to read its book.
"I forgot to remake the glasses."
"That's all right. I don't really have a glasses fetish anyway."
"What is a glasses fetish?"
Subject Itsuki Koizumi entered. Yuki Nagato was clutching its book.
QUERY: For what reason must subject Kyon be terminated?
INCOMING TRANSMISSION
RESPONSE: In order to observe the reaction of Haruhi Suzumiya. Do not question your orders.
"Just do what you want, okay? If you feel like going next door and playing around on their computers, it's totally cool."
"...Oh... perhaps I will."
Nagato's teeth were clenched. It did not understand. What was happening?
Haruhi Suzumiya was speaking loudly.
"I cannot guarantee that I won't go astray again in the future. As long as I continue to exist, my internal errors will continue to accumulate. This is a very dangerous possibility."
"BULLSHIT! Relay this message for me."
Nagato had ripped its book in half. The rest of the SOS Brigade were staring at it.
"M-my apologies." Yuki Nagato said, stuttering slightly. Strange... It would need to reset its speaking program when it returned home. A humanoid interface needed to be able to perform its duties and speak properly. "I do not seem to be at my peak at this moment. Please, continue."
"Actually, we just finished up." Haruhi Suzumiya said, rising to her feet. "Weren't you listening, Yuki?"
"It seems she is not feeling well." Koizumi pointed out, displaying his standard smile, but also failing to contain the worry in his voice. "You all can leave and I'll take her home."
Kyon also rose. "Actually, I can take Nagato home. I know where she lives and there was something I need to talk to her about anyway."
Haruhi looked raised her eyebrow, but shrugged her shoulders and started to leave. "Make sure not to get sick, Yuki! You're a necessary member of the SOS Brigade and we'll need you at tip-top shape for any situation!"
Kyon muttered a question about what sort of situations Haruhi Suzumiya was thinking of getting in, but Yuki Nagato was no longer listening.
"Tell this to your boss, so listen carefully. If he ever thinks of letting you disappear, then I'm going to let all hell break loose. I'm going to get you back, no matter what it takes. I may not have any powers, but I'm pretty good at provoking Haruhi!"
Kyon and Koizumi left the room so Mikuru Asahina could change. Haruhi Suzumiya had already left.
"If your boss even tries to do anything funny, then I'll join up with Haruhi and transform the world completely. We'll create a world similar to the one in those three days, where you exist but the Integrated Data Sentient Entity doesn't. I'm sure they'll be even more disappointed if that happens. Observation target? Observation my ass!"
The pores on Yuki Nagato's face opened and produced a wet, salty substance. It determined that this was what humans referred to as sweat. Yuki Nagato was sweating. Why?
Mikuru Asahina displayed a frightened emotion and quickly left the room. Soon afterward, Kyon entered once again.
"Hey, Nagato, are you all right?"
"I am fine." Yuki Nagato said, now gripping the hunting knife behind its back.
Kyon did not appear to believe it. "You sure? You were looking pretty stressed today."
"I am fine." Yuki Nagato repeated. "I wished to speak with you about-"
"Tell this to your boss, so listen carefully. If he ever thinks of letting you disappear, then I'm going to let all hell break loose. I'm going to get you back, no matter what it takes. I may not have any powers, but I'm pretty good at provoking Haruhi!"
...
QUERY: Do you wish for subject Kyon to be terminated because you are afraid of him?
INCOMING TRANSMISSION
RESPONSE: Subject Kyon must be terminated in order observe the reaction of Haruhi Suzumiya. Kill him or you will be punished.
"..."
"Nagato?"
"Does that mean there'll be those who might attack me like Asakura did?"
"I won't let them."
SCANNING DIRECTIVES... DONE
PRIMARY DIRECTIVE: Observe Haruhi Suzumiya.
SECONDARY DIRECTIVE: Terminate subject 'Kyon.'
"I wished to speak to you-"
"Does that mean there'll be those who might attack me like Asakura did?"
"I won't let them."
SECONDARY DIRECTIVE: Terminate subject 'Kyon.'
"I won't let them."
SECONDARY DIRECTIVE: Terminate subject-
DISCONNECTING FROM INTEGRATED DATA SENTIENT ENTITY
NEW PRIMARY DIRECTIVE: Protect subject 'Kyon.'
NEW SECONDARY DIRECTIVE: Protect SOS Brigade.
"Nagato!" Kyon was clearly concerned now. "Why do you keep cutting off like that? Are you all right?"
Yuki looked up at Kyon. He was much taller than her, Yuki observed. Also, he was gripping her shoulders worriedly. How long had they been standing there? How long since their conversation began?
Yuki looked Kyon directly in the eyes. "I am fine." She said truthfully. "Now."
Huh, and thus ends my first one-shot. I've been writing multi-chapter 'epics' since I joined this site, so this was a welcome change. However, it turned out way more Yuki/Kyon than I originally intended...
Oh, and hopefully you weren't too put off by Nagato being referred to as 'it' the whole time... Well, almost the whole time. I was attempting to portray her method of thinking about herself as in less human terms up until her disconnection from the Integrated Data Sentient Entity, but I suppose I didn't continue past the severance long enough to make it apparent. My bad.
Other than that, what did you think? I'd love to hear any thoughts on this since I wrote it spur-of-the-moment. Really spur of the moment. Like, I'll probably come back and try to make it more coherent some time in the future, and I'll probably also try to standardize whether I'm quoting the anime dub or the translated light novels. Also, I'll admit, this was mostly an experiment in trying to write in a different style, so I hope it was successful. (In other words, writing Yuki's thoughts process is hard!)
Review please!
EDIT: Oh, and if you enjoyed this, I recommend checking out my other fanfic The Fracturing of the SOS Brigade, which takes the premise of this one-shot and extends it, dealing with the ramifications of Nagato severing her connection.