Disclaimer: I don't own it, nobody said I own it, you can't prove I own it!

Author's Note: This idea had been pottering around (pun intended) inside my head for a while, and when I finally saw Half-Blood Prince when it came out on DVD, I just couldn't get the idea to stop bugging me... so here we are.

x x x

Chapter 1: When I Said 'Everything Changes'... I Didn't Expect This!

x x x

Jack woke up to the sound of Gwen Cooper yelling in horror, "JACK FUCKING HARKNESS, GET OUT HERE RIGHT NOW!"

He stretched, and wondered just how the sound of Gwen's voice managed to carry down to his room when even the rift alarm would have failed to wake him if he hadn't installed an extension for it down here. Either way, he could tell this was going to be a long day before he even opened his eyes.

Perhaps opening his eyes was the mistake. Or maybe it was waking up in the first place. He wasn't quite sure.

He had known something felt wrong from the moment he had been so rudely awakened, but actually looking around him had proved it beyond a shadow of a doubt. It had been one of those really tiring Weevil-hunting days, yesterday... he very clearly remembered bringing Ianto to bed with him last night, although nothing more than both of them falling asleep from exhaustion had actually happened.

Now, however, he found himself being determinedly hugged by a young boy, who was clearly equally determined to try to ignore Gwen by burying his face in Jack's chest. "Does she ever sleep? She's more of a morning person than you!" the boy grumbled, and the familiar Welsh accent was all Jack needed to realise that, in spite of appearances, this was still Ianto.

It took him a few moments to realise what else was wrong, here... that someone so young shouldn't still be in the same relative proportions to Jack himself, unless they had both been de-aged.

He nudged Ianto, who swatted at his hand and mumbled, "Sleep, Jack."

"I think Gwen was swearing loudly for a reason." Jack pointed out, almost amused, if he weren't suddenly so annoyed at the higher pitch of his own voice.

This did draw Ianto's attention to the fact that something was wrong, though... and he looked up at Jack now. "Oh shit." he muttered, eyes wide with surprise and confusion.

"JACK, IANTO, GET THE HELL UP HERE, NOW!" another voice yelled down from the Hub. This one sounded more like a boy's voice, as well... and Jack had the unsettling feeling that it was probably Owen.

"I think we'd better do as they say..." Jack suggested, sitting up and deciding it best not to say 'this could have been worse', lest he think of exactly how.

"Y-yeah." Ianto said, quite clearly thinking the same thing, as he quickly scrambled out of bed and tried to find his clothes.

Jack looked around, idly considering just how ridiculous The Coat would look on him, now... and deciding not to wear it, until this strange event was resolved. He too began to try to get dressed in clothes that were far too big for him.

x x x

Up in the main room of the Hub, a twelve-year-old Gwen Cooper sat at her desk, feet up on her chair and arms wrapped around her knees. Her top managed to actually fit, which must say something about how incredibly tight it had been normally, and her jeans were rolled up past where the knees would usually have been.

A very pissed off looking Rhys hovered nearby, glaring around at the rest of the room's inhabitants. He, apparently, had not been affected by whatever this was.

Tosh, who looked no older than ten, was typing furiously at her keyboard, kneeling on her chair because it was easier than trying to adjust its height to fit her younger appearance. An eleven-year-old Owen was inhaling takeout coffee, and pacing like a maniac. Both were wearing their usual work-clothes, shirts too big for them, Owen's pants rolled up like Gwen's, and Tosh's normally short skirt falling past her knees.

It was to this scene that Jack finally emerged from his office, closely followed by Ianto.

"WHAT THE FUCK IS GOING ON, JACK!" Owen yelled, as soon as they appeared.

Jack might have laughed at Owen's voice, if his own hadn't been similarly affected. Instead, he ignored that and answered the question with an excessively ironic tone. "Well..." Jack said, looking around the room, "It looks like we've all somehow been de-aged. I'm guessing eleven, twelve?"

"Sounds about right." Ianto said, nodding, "And since Rhys- what's he doing here, by the way?- obviously didn't get affected, maybe it was caused by something on last night's mission?"

"He's here because he wants to know why his fiancee suddenly started glowing at midnight, and turned into a kid right before his eyes!" Rhys snapped.

"Glowing? Midnight?" Ianto asked sceptically, glancing at Jack.

"Would explain why we didn't notice anything until we woke up." Jack observed. They had gotten to sleep at around eleven.

"Midnight sounds very specific, though..." Ianto muttered.

"Yeah, well I was at home, drinking." Owen snarked, "Apparently suddenly transforming into a kid, and already having a large amount of alcohol in my system, not a good combination... so I passed out." and the overly cheerful way he said that was practically dripping with sarcasm.

"Be thankful drinking's all you were doing, Owen." Ianto said bluntly, causing Owen to stare at him with blatant shock at that suggestion.

"I just woke up like this, too." Tosh admitted, barely glancing up from her computer, "And I can't find anything in the database that could cause this sort of thing."

"So what, we're stuck like this until we grow up again?" Owen demanded, horrified at the very idea of possibly having to go through puberty again.

"It could have been worse." Jack observed, grinning, "We could have been completely regressed to childhood, rather than just physically."

Gwen's eyes went even wider, "What, you mean thinking and acting like children?"

"And memory loss, too, I'd imagine." Jack added.

Ianto shuddered, "Thank god that didn't happen."

"Yet." Tosh said ominously, continuing to search the computer for a reference to this sort of thing. "Oh! I've got something." everyone crowded around the computer, as it beeped loudly, "It's... it's a video message... from Jack?"

"Time paradoxes are fun, aren't they?" Jack's voice- his adult voice- came from the computer, as he appeared in the video image, grinning with a sort of bemusement, "Hello Ianto, Tosh, Gwen, Owen, and... um, me. I'm not going to remember this, once it's over... but after everything that's happened, I don't see the big deal in breaking the first law of time to let you guys know what's happened to you, and what you need to do next."

"Law of time?" Gwen asked, looking at Jack curiously.

"Never tell anyone their future. Especially yourself." he answered, shrugging as the recording continued.

"Last night you found an artifact, looked like a piece of rock-crystal about the size of my fist. All five of you handled it, and then this happened. What you need to do next is all five of you touch it, at the same time. No, that won't reverse it, but what happens next will be a good thing... eventually."

"Eventually?" Owen asked sceptically.

But the recording had only one more thing to say, "Ianto. When you touch the crystal, you'll understand. You'll need to explain everything to the others. And me. You'll see me soon."

x x x

Jack Harkness was none too fond of his job, so when he got the opportunity to take the weekend off he was more than eager to avoid Torchwood. Today, this managed to mean sitting at home reading a book. It was quiet, but it was better than sitting in the Hub listening to his boss pretend he wasn't capable of understanding her underhanded insults.

Very suddenly he heard a loud noise like a whip cracking, and he jumped up, going for his gun. He hesitated when he saw five children sprawling on the floor, as if they'd landed from a few feet in the air.

"Oh god, that was unpleasant." one boy said, looking around very sulkily, before freezing when he saw Jack... or more specifically, when he saw the gun in Jack's hand.

Jack stared at them all in shock, unsure how to react to their sudden appearance. He didn't put the gun down yet, though. He had no way of knowing whether they were some strange alien threat in disguise, or just a bunch of kids who got swept up in a riftstorm.

"I've had worse." another boy muttered, looking far more comfortable with the landing than the others, in spite of the fact that he had ended up on his back with the third boy on top of him. Something about this second boy seemed familiar to Jack, in a skin-crawlingly bad way, and that made him all the more determined to keep his gun on them.

The two girls picked themselves up quickly, to stand next to the first boy. "Where are we?" the slightly older-looking one asked, before her gaze fell on Jack and she fell silent. It didn't take long for all five of them to stand up, and all eyes were now on Jack.

"Anyone care to explain this?" Jack asked sceptically.

The second boy glanced at the others, then stepped forward, taking the lead, "I'm, well... I'm you." he said.

"I think I'd remember something like this..." Jack muttered.

"What year is it?" the boy asked, his gaze travelling around the room.

"Nineteen ninety-three." Jack answered with a frown.

"Yeah, thought this looked like the nineties..." the boy muttered, before announcing, "I'm from your future. Don't ask me why I look younger, because I don't know either, but none of us are really children."

"I'm twenty-six." the third boy muttered distractedly, eyeing an odd-looking bit of crystal in his hands warily.

Jack snorted, "This is ridiculous!" but then a solution occurred, "Prove it." he said, waving the gun at the boy who claimed to be himself. There was a resemblance, now that he thought about it, and if it was true then that could be the reason he felt uneasy about the boy... but there was no conclusive proof.

The boy hesitated, glancing at his four companions, but then he seemed to decide on an answer, "The first time I died was in the year two-hundred one-hundred, on the Gamestation orbiting Earth... I was shot by a Dalek." his voice wavered slightly at the mention of the Daleks, and Jack noticed the third boy tense at the word, too. "And I'd rather you not test whether I'm still immortal right now, since we both know that I wasn't, the last time I looked like this." he added, eyeing the gun nervously.

Jack took a step back, dropping the gun down onto the nearest table and falling back into the armchair next to it, "Wow..." he said, staring at the boy... at himself, "How is this possible?"

"Magic." the third boy said bluntly, and everyone turned to stare at him.

"What?" the first boy asked, "Did you hit your head on the way to the floor, or something? Magic? Are you serious?"

"Well. I have tried researching the phenomenon, it's why I joined Torchwood in the first place. I think it's caused by a genetic affinity to psyonic energy fields, interacting with latent telepathic and telekinetic potential. It can be enhanced using psyonic focus, but I've never actually had the chance to study it first-hand, because I haven't seen real magic since I was eight."

The silence that followed this was almost tangible.

Finally, the first boy broke it, though, "What a load of bollocks!"

"Watch your language, kid." Jack said almost automatically.

"Hey!" he snapped indignantly, pulling a face, "I'm twenty-nine... and I've got a name, y'know."

Jack rolled his eyes, but then his other self- from the future, looks younger, boy this could get confusing fast- said, "That's right, you don't know them yet. This is Owen Harper, Ianto Jones, Toshiko Sato, and Gwen Cooper." he indicated each of them in turn as he said this... then turned to face Ianto, "Magic...?"

The other boy- Ianto- nodded, "Yeah. Okay, basically there's an entire community hidden from the rest of the world. It's easy enough to use these magical abilities in the place of science, and magic was here first, so they tend to ignore most modern innovations. Who needs airplanes when you can teleport across the planet at the speed of light?"

"I can see the logic there." Jack's other self said with a bemused smile and a nod.

"They sort of cling on to older traditions, wearing robes and pointy hats... literally waving wands and making potions." Ianto continued, "My grandfather was a wizard, from a very old family... but my father didn't have the gift, so he severed contact with the magical world when it was proved that I couldn't learn it either." he smiled faintly, "I remember going to Diagon Alley with my grandfather, and getting magical candy. Things like white chocolate mice that literally chased their tails and squeaked... and jelly-beans in the most ridiculous flavours, like chicken curry, tea, or banana and crisps."

"Do they have jelly-babies that scream when you bite off their heads?" Jack's other-self asked very suddenly.

"Um... possibly." Ianto said, giving him an odd look... but no explanation was given for this bizarre question.

"So what makes you believe this is magic?" Toshiko asked, tilting her head slightly in her curiosity, "Or psyonic energy fields and telekinesis? Why not alien?"

Ianto held up the crystal, "This brought us here... and when it did, it felt exactly like a Portkey."

"What's a Portkey?" Owen asked.

"Magical form of transportation." Ianto said bluntly, "Pre-programmed to take a group of people anywhere in the world, travels at the speed of light. In theory you could go to the moon with a Portkey... as long as you had the space-suits, and programmed it in advance for the return journey. No one's ever bothered to try it, though. From what I've heard, most wizards still don't know about the moon-landings."

"This is the biggest load of bull I've ever heard." Owen muttered, turning and wandering off across the room, "Who doesn't know about the moon landings?"

Gwen stepped closer to Ianto, "It all seems a bit far-fetched, that's all, Ianto."

Ianto looked at her, "You work for Torchwood. How is this far-fetched?"

x x x

"You used to live here?" Ianto asked, scanning the room with unnerving interest. The entire living space was summed up in three rooms. The main kitchen/living/dining area, complete with only one chair and a very ratty couch- upon which he and Jack were currently sitting- a bathroom, and a closed door Ianto had not seen the other side of, but he felt that he could safely assume it was the bedroom.

Jack nodded, a bit defensively. He wasn't proud of his time at Torchwood before the twenty-first century, and he hadn't taken any joy in life during this time. It had felt meaningless, and his small apartment had reflected that quite clearly.

"It's... cosy." Ianto muttered.

"Nice word for small." Jack grumbled.

Ianto looked at Jack blankly for a moment, then said, "I was trying to be positive... I can tell you'd prefer it if I don't."

"Please." Jack agreed.

"So have you figured this out yet?" Jack's past-self asked, returning to the apartment with a bag of actual food, instead of the cold remains of whatever takeaway he'd eaten the previous night, "Because I know my boss will kill me if I she finds out this happened. More to the point, she'll maim me first."

"I don't think Carol ever really liked me that much." Jack stage-whispered to Ianto.

"I'm still not sure how this thing even works." Tosh said, peering up from the crystal she had been examining in the middle of the living room floor.

Jack's past-self shrugged, "I've got everything you asked for, clothes that should fit, food, tech- Toshiko, would you care to tell me how a CD player is supposed to help?- and to quote you precisely, Owen, 'enough alcohol to sedate a horse and enough coffee to keep it awake anyway'." he said, staring right at Owen as he spoke. Silence reigned for several seconds, during which Tosh and Gwen were giving Jack's past-self equal stares of incredulous amazement... but finally he couldn't help it and started laughing, "You guys have got to be kidding me, if you think I'd actually do that."

The way Owen's face fell at this was utterly hilarious, but Tosh smiled and Gwen took on something of a morally victorious expression. "But I need coffee!" Owen whined, "I suppose I can live without the alcohol, sure, but... coffee!"

Jack and Ianto both rolled their eyes at this, but then Jack heard something behind him and looked up to see his past self shaking up a can of coca cola and then throwing it at Owen. Owen caught it, but stared in confusion. "If you can drink that without it exploding, good luck. It's all the caffeine you're getting. Kid." Owen glared daggers, while everyone else started laughing.

The good humour was interrupted by a tapping sound on the window.

Everyone turned to stare. Five tawny owls were perched on the windowsill outside, in a neat little row. "It's The Birds!" Owen yelped, scrambling away from the window.

Ianto laughed, and stood up from the couch, quickly approaching the window, "How do you open this thing?"

Jack's past-self walked over to join him, and asked, "You sure it's safe? Your friend seems convinced we're suddenly in the middle of a Hitchcock film."

"Owls are like a wizard's substitute for the mailman." Ianto answered, "And these all have letters, look."

Jack warily approached them both, now... careful to keep far enough away that his past-self wouldn't accidentally touch him, because that could murder the timelines. He could see the neat envelopes attached to each owl by a string around one leg. He watched as his past-self opened the window, and all five owls immediately flew inside.

Tosh shrieked as one flew over and tried to land on her shoulder, it ended up on the floor in front of her instead as she scrambled away from it. Gwen stared, wide-eyed, as one landed on a table right next to her. Owen watched the one that fluttered up onto the kitchen counter next to him, like he thought it was going to turn into a Weevil and maul him.

Ianto was completely unfazed as he held out an arm, and one of the owls landed neatly there. Jack did his best to take a lead from that, pretending not to be bothered as the last owl alighted on his own shoulder.

Tosh backed away from her owl, which seemed to sense her trepidation, and didn't follow her. Instead it held out the leg that had the letter attached to it, effectively asking her to take it. After pecking at a few crumbs on the kitchen table, Owen's owl did the same.

"This is so weird." Gwen said, engaging her owl in a staring-match.

Jack turned to see Ianto had already taken the letter from his owl, and was now petting its feathery head affectionately. He glanced up at his own owl, perched on his shoulder, talons gripping only loosely into his shirt rather than digging into his flesh as one might have expected. It offered him the letter. Cautiously, he took it, muttering, "You said it, Gwen."

Jack's owl lightly pecked his ear, then took off out the window. Ianto's owl followed it.

Still eyeing his own owl like it was evil incarnate, Owen warily took the offered letter, "What if it's gonna explode, or something?" he asked.

"Those are usually red... I think." Ianto said dismissively. Everyone turned to stare at him, but he completely ignored them, too busy opening his letter instead.

Jack ran his fingers over the thick parchment of his own letter, "It's probably safe, guys..." he said, before having to suddenly lean back to avoid a collision with Owen's owl as it soared out the window.

Gwen was still staring at her owl, while Tosh tentatively reached out and snatched the letter away from her own owl. She immediately darted back away from the bird with obvious fear. The owl hooted, causing her to flinch, but then it simply turned and flew back out the window.

Finally, Gwen accepted the offered letter from her owl, still staring at it with eyes so wide Jack wondered if she was trying to compete with the bird. Its work here done, Gwen's owl ruffled its feathers and followed the other four, leaving only the odd parchment letters as evidence that that had just really happened.

"I don't believe this..." Ianto gasped, sounding totally shocked and awed, then he all-but shouted, "Guys, open your letters!"

Jack looked down at the parchment that his hands had already idly removed from its envelope and unfolded. The header in green ink read,

'HOGWARTS SCHOOL of WITCHCRAFT and WIZARDRY Headmaster: ALBUS DUMBLEDORE (Order of Merlin, First Class, Grand Sorc., Chf. Warlock, Supreme Mugwump, International Confed. of Wizards)'

"What's a Mugwump?" Jack asked, and Ianto shrugged vaguely to express his lack of knowledge on this point, his attention still firmly held by his own letter.

"Dear Miss Cooper." Gwen read aloud, as Jack read his own name on his letter, "We are pleased to inform you that you have been accepted at Hogwarts School of Witchcraft and Wizardry. Please find enclosed a list of all necessary books and equipment. Term begins on September first. Yours sincerely, Minerva McGonagall, Deputy Headmistress."

"Hogwarts?" Owen asked, "What sort of name is that for a school?"

Ianto bristled at this, "It's supposed to be the best school of magic in the world, actually." he snapped, before continuing in a stunned whisper, "I was told I'd never be able to go there..."

"I don't understand." Tosh said, frowning as she scanned a second piece of parchment, "You said it was a genetic affinity, so how are any of us qualified for it?"

"This has got to be some sort of joke." Gwen protested weakly, also reading over the letter.

"I'm thinking the same thing, but for different reasons." Ianto told Gwen bluntly, before looking to Tosh, "I've no idea how we're 'qualified' to go to Hogwarts, Tosh... but they wouldn't have sent us the letters if we weren't. They don't make mistakes, I mean look at the address."

"How did they know where we were?" Owen demanded, mildly horrified as he stared at the ripped envelope of his own letter.

Ianto smiled, bemused, as he answered simply, "Magic."

x x x