Contrary to popular belief, the workers at the Department of Mysteries were not true Unspeakables, they were more like middlemen between the Unspeakables and the rest of the Wizarding World, even if they themselves did not know it.

Anyone who worked for the Department of Mysteries would believe that they were Unspeakables, having passed multiple tests to ensure that they were able to complete the work laid out for them by the true Unspeakables.

In truth, it was a quirk of a person's DNA that made them eligible to become an Unspeakable, as the Wizards and Witches of the modern age were the descendants of a group of people who had fled from their Universe, taking refuge in this one, bringing their abilities with them.

Over the course of many centuries, their DNA began to become diluted, almost non-existent in some areas, leading to the birth of squibs, it was later discovered that a long enough chain of squibs having children together may result in just enough DNA being passed on to their children to reignite the Magic, which resulted in what the majority of the Magical World knew as Muggleborns.

People born with a high enough percentage of non-human DNA were able to access higher gifts from their ancestors, each child with the higher gifts was given the choice to become an Unspeakable once they reached a certain age.

Lily Evans, fresh out of Hogwarts, worked in the Department of Mysteries, testing out different forms of possible Universal Transportation Devices.
It was an interesting job, one which was occasionally dangerous, as some of the projects given to her department would blow up in their faces.
However, this one was different.

The history behind it would lead one to think that it led only to death, and yet the research recently done on it said otherwise.
The Veil of Death, or as her papers informed her, was actually called 'the Gateway', which supposedly lead to the Universe that Magic originated from.
Lily, along with her teammate were to go through and investigate, prior tests having shown that it didn't kill those who went through it.
With a deep breath, she and the other lady with her, stepped through.

Harry Potter wasn't normal by any stretch of the Norm, something which he knew. At the age of eleven when he was offered his place at Hogwarts he looked more like a seven year old, he was that short and skinny. He put weight on over the school year but no height.

At the age of thirteen when the Unspeakables had contacted him, he learned just how different he was.
The Unspeakables would often stare at him in wonder, and he understood why, it wasn't because he'd survived the Killing Curse, nor was it because of the things they'd heard from the Hogwarts gossip mill.

No, they looked at him in wonder because he was only slightly human, especially when he took into account the only small portion of human DNA in his mother that he had inherited along with the genetics of his biological father.

He wasn't too surprised to find out that James Potter wasn't his father, as he'd been conceived in a different Universe altogether, he wasn't upset or angry, deep down he'd known that he wasn't related to him, but he knew he would never forget the man's sacrifice to save his life.

Harry was the closest that the Unspeakables had to one of their ancestors in a very long time, and he certainly had the abilities to back it up. All except one, one that he would love to have been gifted with, being able to see Time itself.

Within a short amount of time, he'd not only learnt the Mind Arts from one of the Unspeakables who'd been there for a few centuries at that point, but had quickly surpassed her, easily blocking them from entering his mind, even able to redirect them to another person's mind, or misleading them entirely.

His abilities in the Mind Arts didn't stop there, however, as he was able to invade their minds surprisingly quickly, implant suggestions or ideas, or even warp their view of reality to a terrifying degree.

However just because he was a natural to one of the many things, they were supposed to be good at, didn't mean he was able to pick up others just as easily, Harry struggled with almost every other ability, from mind healing to basic telepathy, Harry struggled to get a clear message across without it coming over as some kind of order or suggestion, taking far longer to get the hang of.

But he kept practising, and when he went back to Hogwarts, glamour charms covering him from head to toe to keep his growth patterns looking human-ish [and as he was thirteen they could even glamour him to look taller and older] he'd do his best to keep up with the exercises the others had given him.

He wanted to do his best, after all. And be the best he could be.

After he'd defeated Voldemort and talked to DEATH in the inbetween he returned scared and afraid. He finished his education at Hogwarts, then went to the Unspeakables full time, almost completely disappearing from the public eye, as most of them, including himself, remained on their many floors in the Department of Mysteries.

While wandering about in one of the many rooms filled with dormant technology, he discovered an item, which worked very similarly to the Timeships their ancestors had once used, with the ability to travel through Time, Space, and even Universes, it had remained dormant until Harry touched it.
His eyes widened as it swiftly changed form and attached itself to his arm, looking like a metallic bracer.

After a brief moment of panic, he reached out and touched the panel he could see, watching it flip open to reveal many small buttons and switches, with a purple holographic screen floating above, which he could interact with by touch.

The object slowly grew more aware and quickly latched onto his mind, and Harry, who'd been taught about the technologies once available to them, allowed her in.

"Small and accessible Timeship," he muttered down at her as he scrolled through the integrated computer to see what he could find, it was set up in one of the languages of their ancestors, created after their own banishment so if the others came they wouldn't be able to understand it, it was a language Harry had learnt, and was comprised of many different shapes and runes, mostly square in origin, "unbreakable?" he hummed as he read the notes left by her creator, "and relatively natural, too.

She chirped at him, and he grinned.

"Small, accessible Timeship, unbreakable, and relatively natural, condense that down and you get S.A.T.U.A.R.N, although with these things you can remove the 'and' it turned it into a perfect name more like S.A.T.U.R.N," he hummed and looked down at her, "would you like to be called 'SATURN'?"
She chirped in agreement and his grin widened.

"Great!"

The other Unspeakables had only rolled their eyes when Harry walked in with SATURN but had quickly realised that they could send him off to check out other Universes, something which he did with a bright grin on his face.

Looking at all of the different possibilities that the world could have taken was fascinating, there were ones where humans had never evolved, ones where they'd evolved faster and were already amongst the stars, there was a terrifying one that was taken over by hostile aliens, and even ones where the apocalypse was happening, both zombie and religious, occasionally both at the same time.

During their trips together, Harry grew closer to SATURN, who seemed to grow a personality of her own, often giving him the occasional sassy comment, while also fussing over him because.

"You are a child, why are they making you do this, Null?"

She had decided to give him a 'better' name a more private uspeakaables name, mere days after she'd woken up, and Harry didn't want to argue, if they were going to be together for a long time, which he thought was definitely going to be the case, then she could give him a name that she had chosen for all she wanted, he kind of liked it too.

Everything was going well for Harry, SATURN, the Unspeakables, and even the rest of the Magical World.

And then the Muggles decided to go to war.

Harry marched through the Veil of Death, an expression of determination on his face.

With how the Muggle war was going, the Unspeakables had sent him to the Universe their ancestors had originated from, to see if they'd be willing to take as many people in as they could, as they tried to run from the war.

Harry knew he was running on limited time, after all, with the constantly open Gateway to this Universe, Harry's constant Universe hopping, and the Unspeakables experiments in Universal travel, the wall between the worlds around theirs was extremely thin, and should the war grow any worse, the Unspeakables would be required to seal it off for good.

They were already preparing for it, it had taken them years to notice the cracks and then even more to come up with a way to close them off. As the
threat of Nuclear Bombs being released grew the idea that their war wouldn't cause problems in other Universes became non-existent. Harry had to try and do all he could to get them sanctuary if they would allow it.

Luckily, Harry seemed to walk out of the Gateway directly into a group of possible Government officials, or something similar.

Holding his hands in the air as guns were pointed at him, he spoke, "I ah, come in peace?

There was a snort before one of the men spoke, "Pup?"

Harry looked at him in shock, before a grin broke out on his face, "Sirius!"

The guns were lowered as the man ran over to him and grabbed him up in a hug, something which Harry allowed himself a moment to enjoy, luckily he had gone through the vail in his natural form so he looked young but his eyes didn't, the hug lasted a few minutes before carefully pushing him away.

"Not that I'm not happy to see you, because I definitely am," he started, "but I'm here for business, I need to speak to whoever's highest up."

At his words, a man walked over, "that'd be me," he informed him, holding out his hand, "Captain Jack Harkness."

"Harry Potter," he spoke while grabbing his hand and shaking it.

After letting go of his hand, the man looked down at him, "what did you need to speak to me about?" Harry looked at the other people gathered, and Jack chuckled.

"Don't worry, anything you can say to me you can say to them."

Nodding, he took a deep breath and began to talk, informing the man of the current predicament of their Universe, giving Sirius the information, he'd been wanting at the same time.

As he was beginning to come to the end of his explanation and get an agreement worked out to take them all in, until they could re-locate to their old planet, Harry was back on his way from London after getting confirmation that the others could come through until they could re-locate, just as he was arriving home, SATURN called out to him, alerting him of a problem, and opening up the screen to the relevant information so he wouldn't have to go digging.

Eyes wide, Harry held his arm up and began tapping at the screen, flicking through the words at an astonishing rate as he tried to enter commands into SATURN

"No, no, no, no, no, no, no," he gasped out, quickly pressing a few buttons and turning a switch, instead of fading out to their Universe, he dropped back onto the floor with a pained gasp.

"Pup?" Sirius called, helping him back up.

"NO!" Harry cried out, tears welling up in his eyes.

"Harry, speak to me, what's wrong?"

"It's gone!"

"Pup?"

He'd taken too long and the Unspeakables had to seal it up, now they were stuck there in the middle of a war with no escape, and it was his fault!

"Our Universe is gone."

Harry frowned at the mobile phone as it rang, Sirius had been sent off with the rest of his team at Torchwood.

He'd been feeling down again, what with it being the Fifth Anniversary of their Universe being sealed away, something which he still faulted himself over.

Still, not many people called his mobile phone, seeing as they could call him through SATURN when he programmed her into their phones.
He didn't recognise the number, but he grabbed it and flicked it open anyway, seeing how only people he trusted even had it.

"Hello?"

"Oh Harry, thank god."

Harry blinked as he recognised the voice, "Jack?"

"Harry, do you know where Sirius and the rest of the team are?"

He blinked, "They were sent off on some special mission, I didn't hear most of it because I was too busy removing a virus from SATURN."

There was silence for a moment, "SATURN can get viruses?" he asked in confusion.

Harry rolled his eyes, "any piece of technology can get a virus, Jack, you just need to make sure you remove them before it gets worse."

There was some muttering on the other end of the line before Jack spoke again, "look, do you mind if we crash at yours for a bit?"

Harry shrugged, then realised that the man couldn't see him not contacting him through SATURN but through his phone, "nah I don't mind, just leave my biscuits alone."

"Alright, we'll see you in a bit, Harry."

Harry rolled his eyes as the line went dead and dropped the phone on the coffee table.

Somehow, he knew this was going to be a long day or two.

Harry lounged on the sofa as he watched Jack, Martha, and the Doctor stress over some guy called the Master.

He could admit that he wasn't very interested in the conversation, although he was definitely picking parts of it up, and whatever was happening didn't sound too good, but honestly, Harry was far more interested in watching the Doctor.

It was painfully obvious just what the man was, and to Harry, it was fascinating, after all, he'd only met those who were so close to being only half or their original DNA before now.

The man before him, however, had not a speck of human DNA in him, he was, as the Unspeakables would have said an ancestor or cousin to the Witches and Wizards.

Suddenly the man turned to him, and Harry quickly looked away.

"You said that this 'Sirius' you live with went away on a mission, who's been looking after you?" he questioned.

Harry frowned, "I don't need looking after," he said, carefully ignoring SATURN's mental protests.

Jack chuckled, "he's right, Doc, Harry's more than capable of looking after himself."

The man dropped it, but from what Harry could see, it was definitely not the end of the conversation, and he had no doubt that he would be tearing into Sirius the first chance he got.

Snorting, Harry rolled his eyes.

It was stupidly easy to follow the three as they attempted to confront the Master, SATURN's built-in cloaking mechanism, combined with his invisibility cloak meant there was no chance of detection.

He'd grabbed onto Jack's Vortex Manipulator as it swept them away to the Valliant, quickly letting go once they were there and following them as they discovered the Doctor's Timeship, or as he called it, the TARDIS.

Harry frowned at the state she was in, and once the other three of them had left, he quickly put a stop to the quickly activating Paradox Machine with a few spells, breaking a few pieces of the needed technology.

He muttered a quick apology as he rushed out of her and followed the scent of the person he knew the most, Jack.

Once he'd reached them, he watched as the Doctor attempted to place something around the Master's neck and failing.

When the metallic orb appeared, he sent a strong blast of magic at it, following its path of origin and patching up the small gap, which would have become a much bigger one had the Paradox Machine been left to activate, rendering whatever the Master's plan had been useless.

The Doctor, Jack, and Martha watched in confusion as this all happened, and once the Master had been restrained, Harry turned off SATURN's cloaking and pulled his invisibility cloak off, grinning and waving at Jack who sighed.

"Harry, kid, you realise Sirius is going to kill me, right?"

"That sounds like a you problem, Jack."

Jack was, obviously, correct.

When Sirius had learnt exactly what had gone on while he'd been away, he'd been pissed.

It was lucky that Jack was immortal.

He'd also turned around to have a go at the Doctor, who often took on companions for his journeys, and should know better than to expect a child to stay put.

To Sirius' surprise, he'd turned around and had a go at him for leaving Harry home alone without anyone to care for him since he was a child.
Sirius had left Martha alone, since she'd not known, nor had the experience, so the only person left for him to tear into was the Master, who'd been stripped of any possible weapons, then had a bracelet that kept him within a certain distance of the Doctor at all times slapped on him.
Once he'd done tearing into the man, Harry snorted, which had him turning to face him.

"And don't think I haven't forgotten about you!"

Harry blinked at him in confusion.

"You are grounded!"

"But I'm already on the ground," He snarked, tapping his foot on the floor for emphasis.

The Master snorted at this, which caused Sirius to glare at him, before looking at Harry again.

"Don't make it two months."

Harry blinked, before shrugging and walking to the door.

"Where do you think you're going?"

"Out."

"I said you're grounded."

Harry stared blankly at him, "Sirius, I'm an adult, I have a job, I pay rent, I haven't been 'ground-able' in about nine years. I'm off to Disney for a break I'll be back later"

"Hey, what do you mean adult?" he heard Martha call out in confusion before he walked out of the door.

Sirius sighed, and Jack, who'd revived by that point patted him on the back.

"You know he's right, Sirius, you can't keep treating him like he's ten or something."
The Doctor stared at Sirius in shock, "what do you all mean he's an adult?"

Sirius looked at him and shrugged, "he's twenty-seven-ish."

The Doctor and the Master both stared at the door, before glancing at each other.

"He couldn't be?" the Doctor questioned.

"No," the Master agreed, "definitely not."

There was silence for a moment.

"But what if he is?"

"Oh, let's be honest, with your luck? He definitely is."

The Doctor paused and then began snickering.

"What?" the Master snapped.

"You got defeated by a twenty-seven-year-old tot!"

"I did not!"

"You did too!"

Sirius looked at the two bickering Time Lords, and then at Martha and Jack.
"Cuppa?"

"Yes please," Martha accepted.

"Coffee, if you will."

With that, the three of them walked into his kitchen.

"The Master got outsmarted by a twenty-seven-year-old tot!"

"Lies!"

"Come on we'll wait inside until he returns then we can talk to him!"

"He is not a tot; I did not get beat by a bloody tot"

"Oh yes you did! Come on we might as well get comfortable!"