A/N: Well, it's certainly been a few months for this fandom! How's everybody doing? I hope y'all are well.

This story picks up where Spock's Brain left off, and before anyone rolls their eyes over the episode I do want to point out that it left some juicy cans of worms open, one of which I will speculate on here. Namely, c'mon there've got to be aftereffects to using the Teacher. While this story was planned to go in just one direction, as I've been writing I've realized that the door I've opened can lead to much bigger issues, and so this tale may evolve into a much bigger net of plot points and twists. You'll see what I mean later.

I, once again, do not own Star Trek. This goes for the whole story. Enjoy!

I am a neuron.

I exist clustered in with my brothers and sisters. I never sleep. At times I am dormant, but most often I am excited. I feel electrical signals zipping through me, up the dendrite, down the axon, crossing the synaptic space as neurotransmitters to spread the word on to my kin. I am alive. I am one of many. I am critical.

I send my response back the way it came. Down the vagus nerve, it goes, got to reach the source.

Shin bone connected to the… knee bone.

My brothers and I are all excited. Lots is happening! We know inherently what is going on, yet our conscious association areas have yet to be informed. Somebody needs to go wake them up.

Knee bone connected to the… thigh bone.

Reds, yellows, greens, blues, how whimsical, since color is just an optical illusion. And besides, the actual brain all looks the same sickly green-grey, anyway. No scan can ever amount to this reality.

So much green blood.

We are delicate. We are special. We are, together, the most important unit. I see your hypothalamus and raise you one medulla. Oh, it's a lot more than mere surgery in the skull, you see. My brain stem travels down further, back, spine.

Thigh bone connected to the… hip bone.

And my nerves! A complete other system! So many connections, oh please get us right, I am excited to feel the signals zipping through me again, oh please, oh please, oh please.

Child's play. A child could do it.

We encode your answer. These signals and bits of 'information' you call, we pass them back and forth like napkins at a dinner party. It's all locked in storage. But your conscious mind doesn't have the clearance.

Now, if you don't think about it, let go,. sleep…

Hip bone connected to the… bone…

Bone.

Bones.

Bones!

McCoy gasped awake, flailing instinctively. His arms collided with something, but it didn't budge. There were voices overhead, but he couldn't make out what they were saying, nor he could he pinpoint where they were coming from. The world was lost in motion-blur, and it took several long seconds for his confusion and rush to calm down, and the fuzzy blob overhead to solidify into the face of his friend, Jim Kirk.

"-ot you, okay? You with us, Bones?"

He gulped and nodded, still breathing hard, but relaxed back onto his bed. A moment later of blinking and frowning and he realized that he was in his quarters. What was Jim doing in here? And, Spock too, for that matter, there he was over by the door. The Vulcan was talking to someone, some people- there was Nurse Radner and a security man by the door. They seemed to be concerned, and anxiously peeked his way.

McCoy turned his head back to Jim. He sluggishly ground his jaw to work. "Wh't's goin' on?"

Jim relaxed some, and finally released his hold on McCoy's shoulders- which McCoy was only noticing now. "Chapel called the bridge when you didn't show up for shift. We called down here and when we didn't get an answer we rushed over expecting an emergency."

"Didn't… up for shift- Jesus, Jim, what time is it?"

"1000, Doctor."

McCoy flailed again and surged out of bed. "Ten hundred?! Holy cow- why didn't anyone wake me?" Did I forget to set my alarm or something?

"That, Doctor, is what we have done just now," Spock pointed out from his position by the door.

McCoy frantically went about the room gathering his uniform. He caught the small crowd still lingering by the entrance. "What are you all lookin' at? You've got somewhere to be, so be there!" he snapped.

With a jump everyone scurried off. Spock dismissed the remaining security guard. He stepped back from the door and it shut automatically.

Cursing in the sudden dim light, McCoy ordered them to be raised 50% and continued trying to gather up his things. "Blasted alarms- didn't mean to oversleep, Jim; sorry for the disturbance."

"It's fine, Bones," Kirk waved off. His brow knitted together. "We had trouble waking you up anyway- nightmare?"

"Hm?" McCoy dragged his medical tunic on over his head. "Oh, no, not a nightmare just…" What the heck was it anyhow? "Just a really trippy dream," he finished.

"Dreams are rarely so vivid that they prevent one from waking two hours past their normal time," Spock mentioned.

McCoy shrugged. "Rarely doesn't mean never." He darted into the bathroom and quickly splashed water on his face. When he came out he looked clinically at Spock. "How are you holding up today? Memory alright? Fine motor skills okay?"

"I am in as perfect a condition as I was before the…" Spock paused. "Incident."

McCoy snorted at the term's shortcoming. "Well, I still want to see you in Sickbay at noon for that neuroscan. You can never be too careful with something like this. We don't want to find out that something's still off at the wrong time, wouldn't we?"

Spock seemed to suppress a sigh. "Doctor, I maintain that further tests are unnecessary. My memories are all intact. My thinking processes are unaffected. My mobility, balance, and physiological responses are all normal. Your tests are beginning to reach redundancy."

"Spock, your brain was removed and then replaced. Excuse me for wanting to make sure that absolutely everything is still hooked up right."

Spock opened his mouth, ready to argue otherwise, until Kirk stepped in smoothly. "Just humor him, Spock. He's right; we can't be too careful."

"Thank you. Noon, Mr. Spock," McCoy wagged a finger at him. "I've got to get to Sickbay."

Kirk pushed off the bed and caught his arm by the door. "And… Bones, today…?"

McCoy looked at him and held out his hands, palms up. "Total fluke. I don't know why I slept in that late. But I can promise it won't happen again, Captain."

Kirk nodded and released him. "Very well."

McCoy grinned. "Catch you later, Jim." He turned and then all but sprinted to Sickbay.

Kirk and Spock were left staring at each other in his vacated quarters. "Well, it's certainly unusual," Kirk said at last.

"Indeed," Spock looked contemplative. "The doctor has never done this before when he is not sick or recovering."

Kirk rubbed his jaw uneasily. "I agree." Yet with no other information at their disposal, what could they do? At last he shrugged. "Maybe McCoy's right, maybe it was just a fluke."

"Possibly," Spock echoed.

"Well, Mr. Spock," Kirk said. "We had better get back to the bridge ourselves."

Spock straightened, agreed, followed him out, and the matter was dismissed for another day.

The routine in Sickbay was a complex, precise machine of order and efficiency. It was by no means boring, but one could normally figure out where a staff member was and what they were doing based on the time of day. This was mildly disrupted in case of emergency, but that system merely collapsed and coalesced into a different one. The same was true with red alerts and performance while in battle.

Sometimes McCoy would exit his office and pause, just standing there in the doorway, watching his staff move about their jobs. He found a peace in that- knowing they were there, knowing he could count on them. It reassured him countless times and calmed his stressed nerves.

Not that anything had been too stressful, lately. Nurse Radner carried a tray of test tubes over there. Orderlies Carter and Hendricks were moving in the replacement lab equipment for cellular screening. It could see right down to the organelles without destroying the cell. Amazing. It would be much appreciated, too, as they would be able to get a quicker look at microbes running rife through someone's immune system. Radner's immune system was behaving well, despite that cold last month. Her nerves were sparking and electricity was traveling all down her system.

McCoy blinked, not fully aware yet. He looked around Sickbay again, but didn't recognize anybody. Large bundles of cells moved about. How complex- he watched the brain and nerves pass the signal of muscular threshold up and down the arm. The muscles responded to lift the equipment. The multicellular meat objects also opened their mouths and emitted noises by manipulating their larynxes. The air was then channeled and changed by their tongue and teeth. Nerves signaled the muscle of the tongue to move, and the mouth to clack up and down.

One meat object walked up to him and made more noises. What a fascinating process. It was amazing how it all came together. The squawking meat in front of him made more sounds, louder and closer together. Nerves sparked and an appendage rose up and gripped his shoulder.

Awareness slammed back into McCoy.

"Doctor? Are you okay? Did you hear a word I just said?"

He looked at Christine Chapel, blinking, and noting her creased brow. "Yes, Nurse. I'm sorry… I was apparently really zoned out."

She nodded uneasily. "I'll say."

"What were you saying?" he asked, much more professionally.

"I was asking if you wanted to test the implementation of the new cellular scanner…" they trailed off, back to business.

While standard equipment performance reports had a tedious reputation, surely they couldn't be this boring.

McCoy leaned back in his office chair, tapping the stylus against his PADD. Granted, he could dictate the report, but until he could think of what to say he preferred to brainstorm with pencil and paper.

Well. Digital template and stylus, at least. One could be forgiven of quaint old sayings when one was born outside of the correct technological time period.

Now, he wasn't some kind of Amish purist, McCoy mused, his mind wandering. The new cellular scanner, for which the blasted report needed to be on, was a world of wonders that would make doctors of past's mouths water. They tested it on various petri colonies of infections, viruses, and other foreign microbes attacking healthy tissue. The information and visualization responded beautifully. Of course, reports had to be much more thorough than that. When McCoy reported in-person to Jim he could be as brief as he wanted, but on paper (again, back to archaic recording materials) the relay had to be much more detailed.

Well, no since putting the darn thing off any longer. Maybe if he just started writing sentences inspiration would strike.

He looked down at the PADD, and nearly jumped out of his skin.

The previously blank page was now covered in some kind of foreign script.

McCoy kept his face perfectly schooled as he made his way onto the bridge. The familiar beeps and voices calmed him somewhat, but for this trip were just convenient background noises.

He walked over to Uhura's station and smiled. "Lieutenant."

"Dr. McCoy!" she greeted, swiveling to face him. Her wide smile showed off her pristine, white teeth. "How are things in Sickbay?"

"Oh, fine, they're just fine. That new scanner's going to be wonders of use, I can already tell."

"That's great."

"And how are you?"

"I'm fine as ever. Did Spock's star analysis bring you by the bridge?"

He hadn't heard anything about that. "Ah, no, actually I came to see you."

"Me?" Uhura seemed both surprised and pleased. "Well what can I do for you?"

Flicking one glance over towards Spock and the captain, McCoy drew out his PADD. "I was sifting through old medical articles in the computer Library when I stumbled across this- it seemed interesting enough, but I can't make out what it says. The translator was no help, either. If you have nothing else in your spare hours I wonder if you wouldn't mind taking a crack at deciphering this?"

Uhura took the PADD and peered at the page of scribbles. "That is interesting," she mulled, chewing her lip. "I'll be happy to look at it for you, Doctor. Could you send it to my PADD?"

McCoy relaxed and grinned. "Of course. Thank you for doing this, Lieutenant."

She waved him off. "No need. I'm already excited to start breaking down this new language."

They chuckled and McCoy sent her the new document. "Well, I'm eager as well to know what it says, and why the computer couldn't decipher it."

"Well, my computer is a bit more flexible in figuring things out," Uhura tapped her head. "Thank you, Doctor."

"No, Lieutenant, thank you," he replied earnestly.

McCoy turned to head off the bridge when Kirk turned around and called him over. Uhura watched him change course and head for his regular spot beside the big chair as the two started talking quietly. She smiled to herself, and swiveled back to her station.

Though, that script was odd and especially unusual that the computer couldn't read it- despite it being in its Library. Deep down, she had a nagging feeling that the doctor was being less than truthful about its origin- but she was too excited about cracking it to pay that thought much mind, for now.

I have been activated.

No time to lose! I begin my journey at the source of stimulus- my receptor on the skin. Now it's a fun race to the top! I weave out of my bundle and rocket up nerve.

Excitedly, I navigate the incredible length. I follow the path throughout the body- I know exactly where I'm going. Do I need to stop at the spinal cord? Nope! It's straight to the top for me!

I twist and turn, navigating my way around the delicate vertebrae. Ah, yes, and this stretch would be the brainstem. No need to stop here, either- I'm going straight to central command.

I weave and wander up to the source. Yippee! Confirmation! And now to respond to the stimulus, so I have to start back down the road I came from. Okey-dokey, then, so I turn around and head back-

-except, ow, there's a big grey wall in the way.

"What in blue blazes?"

...

Scotty was working the night shift again. No, technically he wasn't supposed to, but his lads were loyal and wouldn't tell Captain Kirk.

He worked the nightshift whenever he needed something relaxing to keep him occupied, as rarely anything unusual happened. He enjoyed being at peace with the engines and a few of his good lads. To Scotty, that was the epitome of contentment.

So naturally, it was a bit odd when the doctor visited.

Scotty heard the doors opened and turned to greet whoever was entering, and was surprised to see Dr. McCoy walk in.

"Well! What brings ye by here so late at night, Doctair?" he spoke cordially.

McCoy did not seem to hear him, and instead moved right past him. Scotty frowned when he noticed that he wasn't even in uniform- just the black undershirt and sleeping trousers.

"Doctair?"

McCoy wove an odd path through engineering, and abruptly disappeared into Auxiliary. Confused, a little worried, and motioning some curious engineers over, Scotty approached the little room.

Just in time to see McCoy walk straight into a wall.

The doctor abruptly jerked and spluttered. "What in blue blazes?" he groused, rubbing his eyes.

Scotty stepped forward. "Dr. McCoy?" he called.

His head twisted towards him. "Scotty? Where am I? What am I doing here?" His breathing was elevated due to his disorientation.

"Ye're in Auxiliary Engineering, Doctair," Scotty informed, walking forward. "I think ye were sleepwalking."

McCoy blinked and looked around, calming down. "Sleepwalking?"

Scotty nodded. "Aye."

McCoy dragged a hand across his face. "Well, that would explain it," he mumbled tiredly.

"Are ye alright now? Ye took a hit into th'bulkhead."

"Yeah, Scotty, I'm fine. Sorry for disturbing you. I'll head back to my quarters- and this time lock myself inside." He ambled past, stifling a yawn and glaring at the small crowd of engineers.

"Y'all are on duty- so get back to work!"

They jumped and scurried back to their posts. Scotty watched McCoy leave, still uneasy over the doctor's sudden bout of somnambulism. He seemed alright when he left…

Ach. He'll still let the captain know in the morning.

The bridge was quiet. Spock held the conn as Kirk opted to visit Sickbay for a moment. Used to the routine, the Vulcan silently observed the screen and filled out reports from the chair.

On the hour, Spock rose and slowly worked his way around the circumference of the work stations, observing everyone's duties. He was always unobtrusive in this; he would make sure everyone was working and then move on.

When he came to Lt. Uhura's station she was bent over a PADD chewing a stylus while algorithmic ciphers scrolled across a readout on her station.

"Ship's business?" Spock questioned.

Startled, she looked up at him and smiled. "Just a little project for the down time."

"Learning yet another language," Spock commented serenely.

Uhura tilted her head. "Kind of. It's more of deciphering one. Someone asked if I could crack this script for them."

Spock nodded. "May I see the writing?"

Grinning, as she was quite familiar with his insatiable curiosity, she pulled up the original page and handed the PADD to Spock. She leaned back in her chair, expecting to see that eyebrow rise and a "Fascinating" to escape.

She did not expect Spock to grip the PADD and freeze.

"Where did you get this, Lieutenant?" he asked curtly.

She frowned. "From Dr. McCoy. I have a few words figured out- it seems to be a medically based text, at least, though there are a few ambiguities-"

"Thank you, Lieutenant," Spock interrupted. He handed back the PADD after keying in some directions.

"Mr. Sulu, you have the conn," he ordered briskly. Without looking back, he swept off into the turbolift, headed for Sickbay.

"I don't know, Jim, maybe it's a magic spell."

Despite his intention to be serious, Kirk chuckled. Somehow McCoy's dry, colorful comments always put the other at ease.

He'd come to Sickbay a couple hours after Scotty informed him of the incident the night before. Kirk didn't like the growing oddities in McCoy's behavior. Over the past several weeks there were strange little incidents like that, and the doctor often seemed lost in thought, to the point of vacant mutterings. None if happened often, but the fact that it was happening at all was cause for concern. It was like the doctor wasn't quite himself.

Kirk didn't want to lose him.

"Really, though," Kirk continued after his chuckles subsided. "Are you doing alright? Everything okay?"

McCoy shrugged. "Seems to be from this end. Ship's fine. We're all alive. We're all sane so far as I can tell, minus the fact that we've voluntarily chosen to live in a tiny piece of tin hurtling through space. I don't see any cause for concern."

"I get the context," Kirk said. "But I'm concerned about you."

McCoy sighed. "Jim, other than a few sleeping oddities, I'm fine. My mind tends to wander a lot, but we haven't been very busy since that last mission, so I don't worry about it. Everything's okay, really."

Kirk narrowed his eyes. McCoy was an expert in subversion, but he'd known him for a long time. "You're hiding something else."

"Jim, I've already told you-"

"Told me nothing, really. Just that there's no cause. That doesn't explain why there are symptoms."

McCoy threw up his hands. "If you're going to play doctor now, then I'm going to head to the bridge." He started walking to his office.

Kirk followed him. "It's just unusual for you. I want to make sure it won't get worse."

McCoy grunted and crossed to his desk. "Well, if we don't know what's causing it, it's hard to tell if it'll get worse, huh?"

"So you admit that something's wrong," Kirk pointed out.

"I'm saying-" McCoy broke off with an exasperated sigh. He looked around the office, then looked back at Kirk.

"Okay, Jim. Maybe there are a few slips. But I'm not old enough to be going senile yet. If this is just a phase where I'm off my game for a little bit, then I'm going to let it run its course."

"And if it's not just a phase?" Kirk pushed.

McCoy shrugged. "Then we'll cross that bridge when we get there."

Kirk rocked back slowly on his heels, nodding. "Well… alright."

McCoy quirked a grin. "Now get outta here, Jim, I got the work to do! And so do you, up in the big chair."

Kirk grinned. "Alright. Later, Bones."

He started to exit the office, but caught McCoy's slightly confused look overcoming his fading smile.

"Who's Bones?"

Well? What do y'all think so far? Have I caught your interest?