A/N: This is a fic I started writing a while back, based on a prompt Naru934chan PM'd me. Close to a year ago. Ohhh boy I fail. This first chapter was published on my Tumblr at the end of December, but I never posted it here because this fic really, really needed to be a multichapter. It didn't feel fair to post the first part and then immediately drop it, y'know? I didn't know if I would ever write more.

So, why am I posting it now? Because apparently I am writing more. I started working on it and suddenly have a massive chunk of chapter two done, so this is now a thing that will happen. Well. Chapter two will happen, at least.

There is planned to be eventual Sefikura, and eventual glorious mind-linked smut, but that won't be for a very long while yet. If I get that far. This is actually - dare I say it - a vastly more plot-centred fic than anything I've ever written before. Not that it takes much to achieve that. Ahem.

Warnings: Medical trauma, human experimentation. Just Hojo doing his usual thing, basically.

Sephiroth watched the clock impassively as it blinked past 2100 hours. That made it six hours and forty two minutes that he had been stuck in the Science Department.

Hardly a record; after all, he'd spent most of his childhood in the labs. Even when not required for testing or enhancement, he simply had nowhere else to go. It was more unusual now that he was an adult and the highest ranking member of SOLDIER, since Sephiroth had far better things to be doing with his time. But Hojo would still call him in for further assessments as whim took him.

The majority of the department had long since gone home. Only a handful of technicians remained, most of them attending to various machines that were analysing the samples of blood Sephiroth had recently given. It was terribly dull.

He was required to wait until all the results had come through – more tests or samples could be required, depending on the results – but he was becoming bored with the whole process.

"I'm going to stretch my legs," Sephiroth announced. There were a couple of glances in his direction, but he was largely ignored, and nobody tried to stop him.

He knew these corridors like the back of his hand. He had not always been allowed in all of the rooms, but he knew what was there. Rooms full of computers and analysis equipment, like the one he had been left to linger in previously. The rooms – close to the lab entrance, to present a falsely reassuring appearance – that were no different to a standard doctor's office, where check-ups and testing for SOLDIER candidates took place.

It was only if they were granted the honour of joining SOLDIER that they would be taken further into the labs, to the mako rooms. There was a room specifically for storage and handling, and then rooms with mako tanks and rooms with restraining tables, depending on which method the SOLDIER was going to be subject to. There were several methods of dosing a SOLDIER candidate, but mako showers and mako injections were the most common. The former had been the original way, which Sephiroth had gone through most. The injections came later – more efficient, they said, less expensive than mako tanks. Sephiroth had had plenty of those, too. He had been the test subject for their development, after all.

Sephiroth walked on without stopping to look into those rooms.

Furthest away were the rooms known as 'storage'. It was where the Science Department held their miscellany of monsters and experiments.

Sephiroth typed in the access code without even looking at the keypad.

He was not meant to know the access code, of course. But he had discovered it at eight years old, and it had been a matter of pride to his younger self to always know what it was, even when the scientists constantly changed it on him. He reasoned that continuing to know it now was simply a force of habit.

He certainly didn't visit the area as much as he used to. To a child, with nothing better to do than either undergo testing or train in the VR simulator, the cacophony of wildlife in the storage rooms was a gift. It was the only thing of any interest in the entire Science Department. Sephiroth had spent fascinated hours watching the monsters there; Kalm Fangs, who eyes glowed brighter with mako the longer they stayed in captivity, cockatrices, behemoth calves (the adults were too big to fit indoors, for most of the part). There was a malboro that had been there as long as Sephiroth had; he had watched it throw a scientist across the room once, and adored it ever since. He was very pleased to see the creature still there.

Further down the corridor, a faint green light informed Sephiroth there was a mako tank in use. He hesitated; the contents of a mako tank, particularly one found this deep in the labs, was not always pleasant. But there was no harm in simply looking.

The tank was in storage area 3, a separate room that was generally used to house any overflow of mako-related equipment. Old tanks, a myriad of tubes and wiring, needles, surgical equipment. One of the tanks had been hooked up again, and there was something inside. A person.

That got Sephiroth's attention. There was a sick lurch in his stomach.

It was possible – unlikely, and of course Sephiroth was only trying to rationalise when his instincts already understood fully – that the young man could be a SOLDIER, injured to a degree that required a period of rehabilitation aided by the accelerated healing rate mako provided.

Sephiroth did not recognise him. The young man was shirtless and barefoot, but wore trousers identical to the infantry uniform. He was relatively small in stature, but lean and with enough muscle definition to be in line with the suggestion of a military lifestyle. Blond hair drifted almost upright in the subtle currents of swirling mako. There were needles embedded in the crook of both elbows, though what the IV lines were feeding him Sephiroth could only guess. He didn't wear his dog-tags, but there was a hospital wristband on his left arm.

Sephiroth had hoped for a name, an identifying rank or unit, perhaps. He leaned in to get a better look, but the only thing the tag read was 'Specimen C'.

Sephiroth stared up at the dull grey plaster, ignoring the technicians that bustled around him. There was a needle in his arm, followed by a second, but Sephiroth hadn't felt them as more than a passing annoyance for a long time.

"Who is the man in storage area three?" Sephiroth asked, schooling his voice to sound about as interested as he was in analysing the cracks in the ceiling.

Hojo took a vial of blood from one of the technicians, scribbling a note on his clipboard and frowning. He was usually frowning. "Who?"

"In the mako tank."

Hojo made a noise of exasperation. Sephiroth had been reprimanded often as a child; no questions. A dismissive hand was waved. "Nobody."

"Is he a SOLDIER?" Sephiroth already knew the answer to that one.

"What does it matter to you?" Hojo's tone was clipped. Sephiroth was in dangerous territory.

The next needle in his arm stabbed a little harder, enough to make him wince.

"I was not informed of his absence. If he is a SOLDIER, this oversight can only be the result of a breakdown in communication from my subordinates, and must be addressed."

Hojo's eyes lingered in suspicion. Eventually satisfied with Sephiroth's impassiveness, he turned away. "The boy is no SOLDIER, and no concern of yours. There was an accident in a reactor. He suffered severe mako poisoning. The infirmary could do nothing for him, so he was sent here."

"Does it not seem counter-intuitive to expose him to even more mako if there is any hope for him to recover?"

"Don't be smart with me, boy," Hojo snapped. "His body is dependant on it; a form of mako addiction. Sudden withdrawal would kill him as surely as too high a dose." The clipboard was placed carefully to one side. "If you have time for such tiresome questions, I assume you have time for further testing. We will begin with a sample of cerebral spinal fluid…"

Sephiroth hadn't meant to return to storage area 3, especially not so soon after alerting Hojo to his interest. Yet he found his feet taking him in that direction without conscious decision.

He stood in front of the mako tank, the sickly green glow the only illumination in the room.

"Who are you?" Sephiroth asked.

He did not expect an answer, and the young man – Specimen C – did not give one. He did not appear to have moved in the slightest in the time between Sephiroth's lab visits.

A short moment of hesitation, then Sephiroth made his decision. He turned from the tank and began examining the rest of the room. Hojo was meticulous with his notes; Specimen C would have a file somewhere. Perhaps it was too much to hope for it to be in the immediate vicinity, but there was no harm in looking.

"Was there really an accident?" Sephiroth mused aloud. All he had found so far were dusty old reams of paper for printing read-outs of various machines, most out-dated now. A few piles of basic forms for SOLDIER candidates, all unused. A biro with a chewed end, loose in the back of a drawer.

He returned to stand in front of the mako tank; he would have no luck here. But he would take all the clues he could get. Namely, Specimen C appeared to be wearing infantry blues. It wouldn't be hard to verify. He could get access to the infantry reports – accidents involving a mako reactor were few and far between, it should be easy enough to isolate the relevant incident. All he needed to look for was an infantryman suffering mako poisoning as a result, with a name beginning with the letter C.

(Hojo's naming process was entirely uninventive, Sephiroth knew. He himself had been known as Specimen S for a large portion of his life, until he proved himself worthy of his actual name.)

Sephiroth's eyes lingered on the young man's face; high cheekbones, full lips. Pretty, for a man. He memorised the features, in case they were required to pick out his identity from any photographic material in the infantry records.

"How long have you been here?"

Specimen C did not respond.

"I shall start with the archives for the last month," Sephiroth decided.

"Hojo is lying, isn't he?" Sephiroth asked the unresponsive Specimen C. "There are no records of mako poisoning within the last year that fit your details."

Specimen C no longer had the IV attached to him. It was a cold comfort. They had not just left him here to rot entirely… but being subject to the Science Department's attention was not necessarily the better option of the two.

"But I cannot guarantee the infantry records are correct. They may hide such accidents to avoid staining their reputation." Sephiroth snorted. "As if they had any to protect in the first place."

Sephiroth took up pacing. The small space in front of the mako tank was woefully inadequate for the length of his strides.

"But if Hojo is correct in your requirement for mako – that a sudden withdrawal would damage your health – then I cannot simply take you from here."

That was one reason, in any case. The other was that the recuperations could be severe, for both of them. Sephiroth understood that, the knowledge like ice in his stomach.

He had attempted a foolish, futile rescue once, in his youth. He had grown too attached to a guard hound pup. He had got it out of the labs, and Sephiroth had been so proud of himself. But there had been nowhere for the two of them to go; Sephiroth was only a child, after all, and still lived in the labs himself.

(He had his own room, they said, but it was only a refurbished cell.)

Hojo dissected the pup while Sephiroth was forced to watch. He liked to imagine it died quickly.

Sephiroth's own testing schedule became severe for a long while after that, and needlessly painful. He did not often cry, even as a child, but several nights were enough to bring him to tears once out of Hojo's sight.

He did not think Hojo would have any qualms in doing the same to a human rescued from the labs. Sephiroth was too valuable for them to damage permanently; Specimen C was disposable. Doubly so, as he seemed to have no name and no existence that Sephiroth could discover. No one had reported him missing or noticed his absence.

Sephiroth gingerly brushed his fingertips against the glass of the mako tank. "I understand, what it is like to be alone. It is… unpleasant. I will do what I can for you, but I can promise nothing more than to return."

Sephiroth hesitated, nodded, then turned to leave.

He did not see Specimen C's head tilt just slightly, almost as if attempting to nod an acknowledgement.

Sephiroth was playing a dangerous game, visiting Specimen C so often. He didn't even have any appointments of his own. He could fool the technicians – he was there for testing so often that they were entirely used to his presence and thought nothing of him roaming the corridors at any time of day.

Hojo was a different matter; he personally oversaw all the the testing and enhancements Sephiroth underwent. If Hojo caught sight of him, or even just heard about his presence from the other lab assistants, he would know immediately that Sephiroth was there for purposes of his own.

So he was careful with his timing, avoiding as many people as he could.

Safe in the confines of storage area 3, he would sit on the floor and proceed to update Specimen C on his progress. This part of the conversation was particularly short-lived. But he had started to talk about other things as well. Sephiroth was not the greatest conversationalist, and he knew it. Specimen C, however, did not mind when Sephiroth paused for long periods of time, nothing more to say on a particular subject. He did not care if Sephiroth was unable to correctly read social cues, or used colloquial phrases in the wrong places.

Specimen C had even begun to respond, in kind. Perhaps Sephiroth was just imagining it. But he thought Specimen C straightened up when Sephiroth began to speak. His head tilted forward, like he was trying to listen. His fingers twitched.

Sephiroth pressed his hand to the glass in a farewell gesture. Specimen C's arm began to raise; not far, but it almost looked like an attempt to reciprocate.

"You're still in there somewhere, aren't you?" Sephiroth said.

Sephiroth could read the mood of the lab very well. It had been a skill essential to survival for as long as he could remember. Strange, how he could evaluate the atmosphere of the entire Science Department with uncanny accuracy, yet could completely fail to put a similar skill into practice with friends and colleagues.

There was a buzz of excitement. It was tinged with satisfaction; an experiment completed successfully, then. If it had been something important planned for Sephiroth, there would be nervousness alongside the excitement.

Something had already happened, something a little more important than the everyday monsters and projects they worked on.

Sephiroth slid into a doorway, melting into the shadows as two technicians walked past. He didn't want to be noticed today, not if his suspicions were correct. He hurried to storage area 3 with more haste than he could wave away if he was seen.

The mako tank was still active, and Specimen C inside. The relief was short-lived.

The young man had scars; wounds, really. A great jagged thing down the centre of his chest and stomach. There were deep red pin-pricks that indicated where needles – large ones – had been inserted. The fact that none of these had healed yet suggested they were very, very recent.

"I'm sorry," Sephiroth murmured. He had suspected – known, really, in the back of his mind – that Specimen C was not simply there to heal or be rehabilitated from mako poisoning.

He was weak, floating limply in the tank, exhausted and probably still in pain. His body didn't twitch in response to Sephiroth's presence, as it had so often started to.

Instead, Sephiroth felt it.

There was the burn of the mako. Skin and muscle splitting apart so easily beneath a surgical blade; agony, for a moment, but there was so much of it that blurred into one senseless, crushing pain. Suffocating and trapped, in a body that was nothing more than a dead weight.

And the Lifestream in his head, worst of all. A glimpse of the full scope of life on the Planet; a billion humans, plants, animals, everything; the depths of their dreams and thoughts and suffering, an utter maelstrom of existence. What was one human when faced with the scale of that? A drop in the ocean. Worthless.

Specimen C had lost himself beneath the weight of the world. Was he still there at all?

Sephiroth could not stay to find out. He had felt the same pain as Specimen C before; the physical pain, at any rate. But experiencing it as another…

Sephiroth lurched from the room, pale and with hands trembling. He made it all the way back to his apartment before throwing up.

He did not visit Specimen C again for several weeks.

The guilt gnawed at him. Specimen C was no guard hound pup to be rescued on a whim. He was a human being. Did he have a family, somewhere? Friends? Hopes and dreams? He had been part of the infantry, once.

It was possible he had simply been dressed in the infantry uniform by staff in the Science Department if that was what they had available at the time, but Sephiroth held firm to the idea of Specimen C having been an infantryman originally. It was the only real clue he had for his identity.

And Sephiroth was the only one who knew he was there. Specimen C was his responsibility, and he could not let a human suffer in that gods-forsaken hellhole any longer.

Yet that was exactly what he was allowing to happen.

(There was a bitter voice in the back Sephiroth's mind. 'No one ever cared enough to get you out,' it said.)

He was quiet the next time he visited the labs for his regularly scheduled mako dosing.

"You seem subdued today," Hojo commented, with something that may have been a snort of derision. Sephiroth was not supposed to experience emotions; to do so was weakness. To allow Hojo to notice was utter foolishness. "Are you coming down with something?"

"I doubt it, Professor. I am immune to all known infectious diseases."

Hojo regarded Sephiroth with a cold smile. "But you are not immune to clouded judgement. I would be careful if I were you, boy. The lives of ordinary humans are so fleeting; it would be inadvisable to get attached. Especially to anyone you may meet here."

"…I understand."

Yes, Sephiroth understood, a chill running down his spine.

There was no doubt in his mind; Hojo knew that Sephiroth was aware of Specimen C, and had visited often enough to become distracted by thoughts of his wellbeing. He could not determine if the 'advice' was a reprimand or a threat.

Sephiroth left the labs after his visit, then circled round and re-entered through a less used route. It was vital this time he was not seen at all. They were running out of time, or so it felt.

Sephiroth could sense Cloud's presence, even before he entered the room. He breathed in deep and stepped inside, keeping his defences up.

"What did they do?" Sephiroth asked softly, gaze falling on the comatose young blond.

Specimen C had healed entirely; only the faintest trace of a pink line remained down the centre of his chest. That was no surprise. Mako's healing ability, when applied correctly, was well-documented. (In actuality, mako only accelerated growth. That could be growth of new muscle and skin to knit a wound together… or the growth of mutations, if uncontrolled.)

But Sephiroth could feel him. He didn't understand how; it was like a secondary awareness infringing at the edges of his own. It made the hairs on the back of his neck rise. He didn't like it, but Specimen C was not the one to blame for whatever had caused the change.

What had Hojo done to him?

Specimen C's awareness shifted, ever so slightly, like rolling over in a deep sleep. He was far away, but the sensation was similar to the eyes that stared at Sephiroth's back, only to skitter away when he turned to look at them.

"I'm here," Sephiroth said.

Specimen C knew. Not consciously, but some of the darkness abated. It had been so dark. Dark and lonely, so lonely, abandoned and left to rot.

Sephiroth pushed the sensation away. "If you are anywhere in there, listen. I want to get you out of here." Feeling foolish, he attempted to reach out to Specimen C the same way he could sense the young man's own mind. He tried to let him feel the sensation of freedom, of peace.

Ironic, since Sephiroth was not particularly familiar with either himself.

But Specimen C responded. The tumult in his mind stilled, and all of his awareness turned to Sephiroth.

You came back.

The rush of emotion was dizzying. Relief, desperation, but anger too. He'd been so alone, so hurt, the ache running so deep that he could barely breathe–

"Stop!" Sephiroth hissed. "Whatever you are doing, stop. It is… difficult to concentrate."

Specimen C's presence pulled away, wary of Sephiroth's sharp tone.

"Can you wake up, if I get you out of the tank?"

There was no real response to that. The only sensation Sephiroth could read in Specimen C was vague and confused, like he no longer understood the concept of waking up. He had lost all awareness of anything outside his own mind.

Was it even worth making a rescue attempt? It seemed unlikely the young man would ever recover. But he was clearly aware of what was happening, on some level; it would be cruel to leave him. There had been enough suffering in this place already.

"Very well," Sephiroth said. He was talking to himself more than Specimen C. "I will have to carry you to safety myself. There is a specimen transport elevator we can take to the next floor."

While he spoke, Sephiroth methodically began the shut-down protocol for the tank. He had witnessed the scientists doing so enough times to be familiar with the process.

"Hojo will inevitably come looking for you; it is not safe for you to remain here. It would be best to transfer you to an independent hospital for further care, as far away from Midgar as can be managed. We will stop only long enough for a short rest and to gather supplies. I will also need to investigate transport options, as ShinRa run transport will not be a viable option unless we wish to alert the Science Department of both our location and destination."

There was a low hiss as the pressure released. The glass screen of the tank slid back, and Specimen C slumped forward, utterly limp and unresponsive.

The presence in the back of Sephiroth's mind shuddered. It appeared to sigh, then melted away.

For a moment Sephiroth cursed himself, thinking Specimen C was gone entirely. Hojo had said an abrupt withdrawal from mako could be disastrous–

But, no. It was much fainter now, but Sephiroth could still sense Specimen C. He was simply unconscious, if an awareness could also be considered unconscious in addition to the physical form.

If Specimen C did die, Sephiroth thought darkly, at least he would be free from the torturous half-life Hojo had left him to rot in.

He gathered the comatose blond into his arms. Back straight and head held high, he walked purposefully down the corridor to the transport lift and out of the labs.