I really need to just tone this down and do one story at a time, but, I am still working on my other stories, it's just, when an idea pops into my head, I need to write it down, and I'm already half-way through another chapter for this story.

It's mostly that I wanted to try my own idea for a de-ageing story.

I managed to get the name, "Merlin Sickness," by researching a few websites and finding that it is often used for the meaning: aging backwards. I adapted it slightly, since Harry isn't aging like Benjamin Button, but for all intents and purposes, he did jump from 13 to 5 in one night.

Disclaimer: as much as I wish I did, I don't own Harry Potter

Sirius stared down at the child in horror.

He was pretty sure that this wasn't supposed to happen…

The child blinked up at him with bright green eyes. "Hi."

Sirius blinked once again, kneeling on the ground before the five year old… or what looked like a five year old. "Hi." He replied softly, watching the boy draw a stick figure in the sand. Sirius cleared his throat.

Harry glanced up at him. "Didn't your Aunt and Uncle teach you not to talk to strangers?" He asked softly. That was essential. If he had just up and left with some random person… they could've been a death eater.

But Harry shook his head before turning back to his drawing.

"I thought you would be…" he paused, as if wondering how to word it, "older…?"

"I'm five," he told him softly, peering at him from under his fringe. "I left though, b'for Uncle Vernon could get angry – he was really mad this morning when he saw me."

"What happened?"

Harry shrugged as the man scooted closer to him. "I don' know, but I was in Dudley's toy room – and I'm no' 'llowed in there… and there were strange things in there!" His voice rose, eyes bright, and he leaned forward as if sharing a conspiracy, "A picture was moving!"

Well… at least it was normal strange… not wizard strange… nothing too bad.

"And there was a- a- a cauldron!" Harry looked back at him, emerald green eyes staring in Sirius' own grey, "But it was bubbling and weird!"

Damn it Merlin! Sirius could tell what probably happened…. Harry didn't live with proper wizards, and he couldn't use magic during the holidays… but there was nothing about brewing potions.

But he lived with muggles who couldn't deal with the side effects.

Damn it.

"Anything else?" Sirius asked him before he could retreat back into his shy shell.

But Harry nodded, smiling softly as he glanced down. "There was a stick, and a blankie – it looked like a curtain." That didn't explain much but…

"Do you want to show me?" Sirius asked, he had to get the boy out of here… he was just a kid… he was – he should just admit it. Harry was an adorable five year old and Sirius just wanted to kidnap him and have his chance to raise him up right. Better than Vernon and Petunia could ever hope to achieve at least. "I could show you a secret, but you can't tell anyone."

"Really?"

"Really, really."

Harry looked up at him with curious eyes, as if silently demanding that he show this big 'secret' of his.

"But you can't tell anyone," Sirius told him, raking his eyes across the abandoned old park in search of any eavesdroppers. He settled his eyes onto his godson. "It'll be our little secret."

The child puffed himself up slightly, "I can keep a secret," he told the man excitedly. "I'm good at keeping secr'ts."

He sent the boy a warm smile before, without warning, allowing himself to transform. His face lengthened, his body curved, ears grew – and a large, shaggy, emancipated dog sat in front of a five-year-old Harry Potter.

The boy, for his part, was taking the change quite well.

Well… if well was the fact that his face may never be the same quite again….

Which could, in fact, possibly be true, seeing as Harry was staring at him with wide, shocked eyes on his slack-jawed expression.

Sirius padded up toward the boy, his wet snout pushing the boys mouth closed as if to tell him that if he stayed like that then he would catch fly's in his mouth… although the boy could do with some food…

"Wicked…" Green eyes stared at him from behind overly large glasses, "can you do that again?"

He made a small huffing noise that could've been a snort, before butting his head against the boy's ribcage.

Harry frowned, attempting to balance his glasses on his nose, as he glanced down at the man-who-turned-into-a-dog. The man-who-turned-into-a-dog who was currently tugging at the strange robe-like clothes that the boy had found himself in.

The clothes were much too large for him.

"I'm not 'llowed to bring dogs in the house…" Harry muttered, but obeyingly trudged his way back to Number 4, ignoring the stares of the neighbors with practiced ease. "A'nt Petunia doesn't like dogs…"

Sirius whined.

"I like dogs," the boy amended quickly, not wanting to make the man-dog angry, "well," he added after a pause, "not A'nt Marge's dogs, but those dogs are icky."

He plodded past Number 6, unintentionally jumping over the line in the sidewalk as he turned toward Number 4's front door.

"Uncle Vernon's not home," he commented, staring at the empty driveway in confusion… he hadn't thought that Uncle Vernon had anywhere he had to go…

He walked to the door cautiously, the dog padded silently behind him as he attempted to turn the knob.

Attempted being the key word.

" 's locked…"

After a moments silence, the dog-man whined again, pulling the boy by the oversized robe once again as he made his way around the house.

Harry followed dutifully and a bit confusedly.

Once Sirius had successfully found the back door, he transformed back into his normal self, his dark, gaunt, matted appearance would have given several people an awful fright had they seen him. He tested out the door to be sure it was locked before waving a hand over it, muttering darkly under his breath the entire time.

The door creaked open.

The boy stared in wide-eyed wonder as the man crossed the threshold.

"Come on then," Sirius said, beckoning the boy to him, and Harry scrambled inside, closing and locking the door on his way, "you look half starved."

He lifted the child up easily as the boy finally reached him, and placed him onto the tabletop as he turned toward the fridge. "Anything in particular you're in the mood for?"

"I'm not 'llowed to eat 'less it's a meal time."

Sirius bit down his surge of anger as he rooted through the Dursley's fridge. "You're allowed to eat if I say you're allowed to eat," he finally settled on saying as he took a jar of jam off the top shelf. "And I say you're allowed to eat.

"Err… actually, where's the bread and peanut butter?"

Harry silently pointed to the cupboard above the fridge. Sirius opened the small wooden doors, thought for a moment, then took both loafs of bread, and a couple of jars of peanut butter, plus several other snacks (chips, pop tarts, cookies, etc). He placed the food onto the kitchen table beside the jam.

"Why don't you show me the… weird stuff, Harry?" Sirius grabbed a cookie, ushering his godson up the stairs despite his protests, "It can't be too bad," he told him, shoving the cookie into his mouth.

It tasted heavenly.

"I'm not 'llowed in Dudley's toy room." The boy said finally stopping in front of a white painted door with several heavy locks. On the outside.

Sirius didn't like the implications of those locks.

"It'll be fine," he told the boy, kneeling beside him, "they don't even have to know that we went in there."

"Pinky promise?"

Sirius blinked in silent confusion as the boy held out his right pinky solemnly. "Err…" Might as well just go along with it…? "Pinky promise," he acquitted with a nod.

Harry waved his hand around, pinky still raised, "you haven't pinky promised yet!" He locked his jaw as he looked up at the man with a critical eye, "and we've gotta lock it."

"Err…" What…?

Harry frowned awfully at him.

"… I don't exactly know what a pinky promise is…"

Harry gaped at him. "You don' know…" Straightening his posture, he grabbed the mans hand, ignoring the dirt and grime, and wrapped his pinky around the strangers pinky. "You gotta' lock pinkies," he said as Sirius allowed his pinky to wrap around the smaller one, "an' put the thumbs toge'er." He attempted to reach the man's thumb, succeeding only when Sirius pressed his thumb against the boys in amusement.

"So that's a pinky promise?" Sirius asked once he'd been allowed to take his hand back.

Harry nodded, "and if you break the promise, I get ta' break your pinky."

Sirius, not liking the sound of that, nodded anyway, wondering what the hell those muggles had been teaching his poor baby godson…

But he kneeled down, smiling at the boy, and nudged him toward the door, "How 'bout we go in then, as I'd rather not break my pinky, we'll be sure that your relatives don't find us in here then." He smiled affectionately, which felt rather odd on his face after so long in Azkaban, and stood, Harry giggling at his expression.

He grasped the knob tightly in his hand, eyeing the locks rather wearily, before pushing the offensive door open.

The room didn't really look like a teenagers room all that much. Shelves lined the walls, broken toys and electronics sitting upon then, and the untouched books seemingly gathering dust from the lack of use. An old digital ("That is the word, right?" Sirius thought idly) clock had bright red numbers practically screaming the time from behind the broken glass. A bed was shoved up in the corner as if were only an afterthought.

The only things in the rather cramped room that looked as though it may belong to Harry (unless his godson had some major anger issues) was the Hogwarts trunk, still half packed, at the edge of the bed, a picture of James and Lily that Sirius had taken only months after they'd married, dancing, dancing through the autumn leafs without a care in the world…

But shoving the robes hanging out of the open trunk out of his mind, the picture that caused a painful lump to form in his throat out of his mind… he focused on the cauldron in the middle of the room. It was, indeed, bubbling. And blue. A bright blue… still smelled like gym socks though.

Harry scrunched up his small nose as he went to poke the cauldron.

Sirius grabbed the child's hand before he could, "No touch," he told the surprised child rather firmly, hand clutched tightly in his own as he pulled the child to the 'blankie that looked like a curtain'… James' old invisibility cloak….

Still holding Harry's hand, he slowly ran a hand over the silk-like fabric… "You've got quite a collection here…" He told him, setting him onto the bed before picking a broom up off the floor.

"Dunno whys that there…" Harry muttered peckishly, obviously not over the 'no touch' policy. " 's no good fer cleanin'…"

"Remind me to have a good, long conversation with you about how wrong that sentence was," Sirius told him, tracing the words Nimbus 2000 with wide eyes, "this piece of art is beautiful…" Not even twelve years in Azkaban could dent a Quidditch fanatic's obsession. If anything, it probably just got worse.

Harry, taking the man's silence at face value, jumped down onto the floor, moving to peer into the cauldron….

Before Sirius grabbed his hand once again, "No touch."

Harry pouted.

Sirius bit his lip, pulling the child back to his bed, and thought back to the food sitting innocently on the counter downstairs. He could take Harry and run, but he had no potions expertise – at all. He could leave Harry here, but what would await him…? The locks on the door (a bedroom door) held no promises.

"Hare?" The man kneeled down before the boy, his grey eyes catching familiar emeralds, "how would you like to come with me?" No backing down now… although… damn – it was no use, he'd have to – "my mother had a house, she left it to me when she died."

It was more likely that no one wanted the house when she died.

"I–" the boy cut himself off, biting his own lip in a reminiscent way to the man in front of him. "I don't even– I don't–"

"I can show you why all these… objects," he said after a pause, "are in your – your cousin's toy room. And you can decide," Sirius swallowed, his mouth suddenly dry, "you can decide whatever you want to do."

He stared up at him cautiously, much more cautiously than any 5 year old had a right to be, Sirius hoped it was just a side effect from the potion. "What if I want to go hand gliding…?"

Sirius laughed in, what was it? Relief? Paranoia? Horror? Happiness? He didn't know. And he didn't exactly care. "We'll have to see," he said softly, "we'll figure it out."

"Okay," he said, rather simply, in that simple way that five-year-olds will accept nearly anything. A shy expression suddenly creeped across his face as the child ducked his head, peaking up at the man through his bangs. "But I don't… I don't know your name…"

Sirius blinked in surprise, a small pang of regret washing over his face before a soft smile was directed at the boy. "Sirius," he told him, "Sirius Black, your godfather."

He didn't think that the boy's eyes could get any wider.