Disclaimer: Don't own KH of FFXV

Chapter 1

Eraqus moved swiftly through the corridors of the building he had found himself within. It made his skin crawl, there was Darkness saturating the halls and yet…it was unlike anything he had felt before, almost….sentient? That could not be good. His goal was to leave the building and the feeling of Darkness behind, summon his Glider and return home. Whatever had knocked him off course and onto this strange World he didn't know, he had not seen or sensed it until he was tumbling through the Lanes Between, landing in this World.

There did not seem to be any magic in the place, which was good, it was all that was allowing him to go unseen, but he did not believe it would last, another reason to hurry. He had glanced armed humans throughout the building and he did not wish to break the World Order in order to defend himself. He hesitated when the sound of battle reached him, it was nothing he was able to interfere in…and then he felt a blast of magic.

He moved even quicker, it was definitely magic but unfamiliar; cold but not Dark. He moved around a corner and saw a man, younger than himself, with short hair, wearing black and wielding a long sword. He was defending two others who were working on something he could not see.

"Marshal we have to retreat!" one yelled, and the man looked back.

"Have you got it?" the man called back, voice utterly calm.

"No sir!"

"It's the Immortal!" one of the local soldiers called out in fear.

An interesting if concerning title, true immortality was not possible, was it? He was torn over whether or not to interfere. That was not Keyblade magic, which made it an internal issue, unless this Immortal was a World traveller?

"Marshal!" the second, a woman, called, one arm hanging limp even as she crushed something in her hand…ah the local variant of a potion it seemed as she regained partial use of the limb. They were sorely outnumbered….

"GO!" the Marshal yelled, glancing at the room they'd been trying to gain entry to, the three in black retreating from those in white.

Eraqus found himself curious as to what they had been so determined to reach so once the fighting had moved on, he summoned his Keyblade and unlocked the door, entering silently. He found a room of strange metal pods…the lights on low…no coming from cylinders on the other side of the room. All were empty, except one, and now he knew why they had fought so hard to enter.

In that moment, he cared nothing for World Order and only for the small form floating limp within. Younger than the children who already resided with him for learning and that made what he was seeing even worse. The boy could not be more than four or five years old, his head shorn, leads and tubes going into his body, far too skinny… he aimed his Keyblade again, opening the tube, the liquid within rushing out even as he moved forward to catch the child, removing everything from his as quickly and painlessly as possible. He dug out his spare coat from his magical pocket and wrapped the unconscious form within it, the child far too light to be healthy. He would need a lot of care to recover from whatever had been done to him and Eraqus knew he didn't have that time to spare, not really, but how could he leave him there? As alarms began to blare anew he took off, he would make an exit if he must. Taking the child into the Lanes was dangerous but no more so than leaving him there would be.

Finally, he emerged into a frozen landscape and opened the gate, calling his armour even as his Keyblade transformed. He cradled the limp body close, keeping him tucked up tight to protect him as best he could for the journey home.

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Aqua hurried down the hall, the tray held very carefully. She was worried, Master Eraqus had returned late and immediately sent her and Terra to fetch medical supplies. Was he hurt? She almost ran into Terra as he appeared with more equipment and they went to the normally empty guestroom their Master had told them too, only to find him standing over a very occupied bed. There was a boy lying on it and he really didn't look healthy.

"Master?" she called.

He glanced at them. "Good, come, I shall need your help."

Soon, the three of them were working hard on the too small body, Aqua biting back tears as she took in the evils that had been done to him.

"Who could do this to a child?" Terra demanded once they had done all they could.

"Some form of military based on where I found him," their Master answered. "There was a small group attempting to gain entrance to the room he was held in, whether they were his kin or not, I do not know. He cannot be returned there, should he survive he will remain here until healed and then we shall see."

"I will watch over him tonight Master."

"Very well Aqua, summon me should his condition change." He nodded to her and left.

Terra reached out and squeezed her shoulder. "I'll bring you some tea and a book and take over in the morning."

"Thank you."

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Terra looked up at the soft sound, hoping it meant the kid was waking up finally, it'd been three days since Master Eraqus had brought him to the Land of Departure and he hadn't stirred yet. He was shifting weakly, restless, face flushed, and Terra frowned in concern. He reached out to touch his skin and recoiled in horror.

He got up and ran for the door. "Master! Aqua!" he yelled before returning to the bedside. He grabbed the pitcher of water and poured some onto a cloth to bath the pale face.

Aqua burst into the room and immediately moved to the bed, green healing magic leaping to the child.

"He has a fever," Terra told her.

He was soon standing back as they worked on the boy, until he heard Aqua gasp in horror.

"What is this?" she asked, and Terra moved to see her holding the boys arm up to reveal blackness on his skin.

"I don't know," their Master admitted. "Keep his fever down and ensure he drinks to remain hydrated, I will send for further aid."

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Yen Sid was surprised when Eraqus contacted him for medical assistance but he stood from his desk and gathered what he may need, including his own apprentice. It would do him good to learn more of the healing arts. He had never met either of Eraqus' apprentices and wondered which had fallen so ill that he could not deal with it.

He transported them to the Land of Departure and led the young King into the castle where they found a tall young man waiting. He bowed and then motioned for them to follow. "Thank you for coming so swiftly Master Yen Sid, please come this way."

"Can you tell me anything more of her condition, Terra?" he asked as they walked, Mickey silent at his side.

"Her?" Terra looked at him before his eyes widened. "Oh, no, it isn't Aqua who needs help. Master Eraqus returned with a young boy. He…well you'll see. But he has developed some sort of illness as well that Master cannot identify or cure."

"I see, then we should hurry." That did not sound like his old friend at all. How had he come to have the child? It did not sound planned at all.

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Mickey followed his Master into a good sized room, seeing a man and girl, a teenager, leaning over a bed. Yen Sid quickly joined them and Mickey edged closer to watch, he could manage the standard healing spells but what they were doing was beyond him. He got a look at the child and felt sick. Who could do that to someone? He was so pale, as if he'd never seen the sun, his hair shorn to his skull, limbs little more than bone covered skin and in that skin…there was metal in places. The skin was thin and…what was that?! He'd never seen anything like it and it felt…wrong. Very wrong, Dark. There were streaks of something black on his skin, almost like bruising or some kind of rash or something. Whatever it was, it felt unnatural to him.

"Who is he?" he whispered.

"We don't know," the young man answered just as softly so as not to disturb the others. What had Master Yen Sid called him…Terra? "Master Eraqus found him in a tank, hooked up to machines, inside some kind of military base. A small team had tried to reach him but had to retreat. He hasn't woken since being brought here."

"I admit, I haven't been around a lot of humans so I have trouble judging ages," Mickey told him.

"Master Eraqus and Aqua think he has never left the tank he was found in due to the tone of his skin and lack of muscle, that makes judging his age harder, but they don't think he'd be older than four.

Terra moved then, catching Aqua as she stumbled, obviously exhausted, helping her to a chair. Finally, the two Masters stepped back as well, even as the child whimpered in distress. Mickey wanted to comfort him but did not know how, he and Minnie had no children of their own, not yet anyway. He had never really been around any.

"Master?" Terra asked.

"We have not been able to remove the infection, it is insidious," Master Eraqus admitted.

"If we cannot stop it, the boy will die," Yen Sid told them, and Aqua bit back a sob, not that Mickey blamed her, he was so little…

"Is there nothing else we can do?" he asked.

"Perhaps," his Master admitted. "I shall return."

"Terra, show King Mickey to a guestroom please."

Mickey saw the young mans' eyes widen at his title, but he nodded and led Mickey to a nearby room.

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Merlin made his way to the small home on the outskirts of Radiant Garden. He had listened to Yen Sid's explanation of the child's ailment and he knew that the woman dwelling within may be his only hope. He knocked and a young woman with long brown hair and green eyes opened it, a young child clinging to her skirt. "Lady Ifalna, a dying child needs your aid."

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Aqua watched the other woman as she worked on the boy, relieved that whatever she was doing seemed to be working, the blackness receding slowly but steadily, the fever going down. It was a relief, he was so young…what had they been doing to him and why? How could anyone hurt a child like that? She absently listened as her Master and Master Yen Sid spoke together.

"All that can be done has been," the woman finally said, standing up tiredly. "The disease is gone but it has left a mark on him and I can do nothing about the technology within his body."

"Thank you," Aqua told her, and Ifalna smiled gently at her.

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Eraqus watched as the small boy began to stir, it had been a week since he had rescued him and if he had not woken soon then more intervention would have been needed to ensure his body could not deteriorate further. The child whimpered in distress and he placed his hand on his forehead. "Easy little one, you are safe now," he soothed.

Ever so slowly, blue-violet eyes fluttered open, unfocused. The boy tried to move, to sit up, but was too weak, breathing speeding up.

"Shh, you're alright," he murmured, and those incredible eyes slowly focused on him, the boy seeming confused. "Can you understand me?"

That got a weak nod which was good. If he had been raised in that tube there was no reason to believe he would be able to understand speech or even speak himself. The boy licked his lips, "Unit 05953234….functional. Awaiting orders," he voice was barely audible, but Eraqus felt sick at his words.

"There are no orders here little one, you are here to rest and heal." His worlds obviously confused the boy, he began struggling to rise, seeming puzzled as to why he couldn't. "Sleep now," a little magic had the boy going limp, eyes slipping shut. It appeared there would be more to his healing then just his body.

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Terra slowly lifted the small body, practically able to feel the fear radiating from him. "It's alright, you're safe," he murmured, cradling him to his chest before walking out of the bedroom.

Aqua was digging through the storage areas for things to furnish the room with, toys and the like. Whatever had been done to him before, they were going to teach him how to be a kid. Master Eraqus had admitted to seeing only one person use magic back in the boy's world, so they didn't know if he'd be able to learn magic or perhaps summon a Keyblade one day. Would they send him away to another world once he had recovered if he couldn't, somewhere he'd fit in and be with other children?

He walked slowly through their home, acting like he didn't notice the kid cautiously looking around, curiosity growing, that was a good sign, right? Finding out he had a number and not a name…he'd had to spend a lot of extra time on meditation since then. They'd have to come up with something soon, they couldn't keep calling him kid.

He walked out the front doors and the kid whimpered in the sunlight, pressing closer to him, shaking. "It's okay, I won't let anything bad happen to you," he promised. Had he really never been outside before?

"Forbidden," the boy whispered, one hand weakly clutching at the strap over Terra's chest.

"Not here, kids need lots of sunlight and fresh air to grow up big and strong," he told him, and for the first time the kid looked him in the eyes. He really did have a striking eye colour, Lady Ifalna believed it left over from the disease he had carried as his eyes had been turning red, they may remain their current colour or become more blue as he grew.

Terra sat down on a bench, keeping the boy in his lap for comfort and warmth, he was so skinny that he was having trouble regulating his body temperature and had no, well, padding, for sitting on something so hard. He was dressed in some of Aqua's oldest clothing and was swimming in the shirt that was a dress on him, terra's things would have been even more ridiculously oversized, partially because they'd both been older when they had been taken in by their Master.

Did the average four year old use big words like forbidden? He didn't think so, which meant he was one very smart kid. Gradually, the kid uncurled a bit, blinking in the sunlight, and Terra shifted slightly to help shade his eyes a little.

"See? Nothing bad will happen." He ran his hand over the shorn hair, wondering what colour it would be when it grew. They were working to get him used to painless contact and it was always good when he didn't flinch. "We need to find you a name," he told him and the kid glanced at him.

"Humans have names. MT's have numbers," he stated. They'd been carefully coaxing information out of him since he'd woken. Master Eraqus wasn't entirely sure what an MT was but the boy had obviously been told he wasn't human, which was ridiculous.

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Eraqus watched as Aqua sat with the boy in the library, working on a child's book with him. He already knew the basics of reading and it was something that could be done without stressing his body. A month of good food, sun, and careful exercises had made a vast improvement in his appearance. Fine, bright, blond hair was growing in and his skin had gained a much healthier colour. He couldn't walk yet, could barely feed himself and was still on very bland food, but at least he was on solids and gaining muscle tone.

He had contacted Yen Sid again, this time for help working out the boys' identity. Using magic to determine it had not been easy but it was done and now they could finally have a name to call him.

Eraqus stepped into the room and the child immediately focused on him. He was trying to teach the child to not see him as his superior as he would someone in an army, but as a teacher and guardian. "Good afternoon Aqua, Prompto," he greeted them, hiding a smile as Aqua froze and then her eyes went wide.

"Master?"

He walked over and knelt done to take a small hand in his. "Your name is Prompto Argentum, child."

"Prompto Argentum," he parroted, head tilted to the side. "But…" he looked between them with wide eyes, and Aqua ruffled the very short hair.

"It is a very nice name, much better than a number. Does the name have any meaning?"

"Indeed. When put together, they mean Quicksilver."

"Argentum is silver, Prompto is quick or ready," Prompto told them, nose scrunched up. "They are Lucian, this unit is from Niflheim, not Lucis."

"When I found you, there was a group trying to reach you, they were dressed all in black and they called one Marshal and Immortal," Eraqus told him, wondering if Prompto…the boy paled, eyes wide.

"The Immortal?" he whispered in awe and…fear. "Marshal of the Crownsguard, loyal soldier of Lucis."

"How do you know so much when you're so little?" Aqua tickled his side, and he giggled before freezing hunching in as if expecting to be hit.

"MT's are genetitically altered for peak performance in all areas."

That was a very complex sentence for someone so young, other than one slightly incorrect word. His vocabulary was large but also limited as well. He knew a lot of words to do with the military, training, weapons…but he hadn't known what a bed was. He was learning very quickly though.

If Eraqus ever found Prompto's home World again, he was unsure that he would be able to keep himself from confronting the Emperor that had commanded Prompto and who knew how many other children be created to fight his war. He was definitely better off with them and having him there to teach was actually helping his students. Terra was becoming better at patience even as he helped very carefully teach Prompto to walk. That had been confusing, what was the point to a soldier who couldn't walk? Prompto had told them of what that disease he had been infected with did, that it would convert their bodies to 'miasma' to power metallic armour. Thankfully, it was obvious some of it was pure recitation, he didn't understand the horrors fully.

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Terra knelt on the grass, hands held out towards Prompto who was frowning adorably in concentration. Shakily, he took a step and then another until he tumbled into Terra's arms. He picked the boy up, spinning him around carefully. "You did it!" he praised, and Prompto smiled shyly, clinging trustingly to him.

He'd come so far in a year with them and he wouldn't trade their little brother for anything. He still had days where he found it hard to do anything but follow orders, but most days he was just a very smart, bright, little boy. Master Eraqus had warned that once he had walking down, it was likely he would pick up running very quickly and that would make things interesting, but Terra was looking forward to it. He was really hoping that Prompto could truly join them, that one day he could wield a Keyblade at their side.

TBC…

So I'm putting Aqua at fourteen and Prompto at four at the beginning of this, so Terra's fifteen. I was trying to find out when Ventus joined them, cause none of them seem to age between then and the events of BBS, despite the fact that surely it would have taken a while for them to become so close.

Pairing suggestions for later?