A/N: I do not own Doctor Who, Torchwood or Harry Potter. I am merely borrowing the characters briefly. Follows the HP timeline, meaning Amy and Rory get taken back to 1981.

On October 31st, 1981, the Potter House in Godric's Hollow exploded. The official explanation was a gas explosion. Even UNIT had trouble getting to the bottom of it. Torchwood London fared little better, though a certain member of Torchwood 3 might have had better luck if he had been called in. But he wasn't.

What caused it was the (temporary) demise of a very dark wizard via the protection of a dying mothers love for her child. And it attracted the attention of many powerful beings across the Universe. When Voldemort acknowledged that Love was an ancient magic, he wasn't wrong, and the creation of a Love protection of this power was something that even otherwise apathetic beings were bound to notice.

But the one who got there first was a very empathetic and energetic being, who had just said goodbye to his grieving companions who had lost their child. And he could not bear to hear a child cry. Around five minutes after Voldemort was defeated, the TARDIS landed outside Godric's Hollow, taking her wonderful Thief right where he was needed. The Doctor stepped out of the doors, a little puzzled as to why the TARDIS had taken him here. Then he saw the smoking ruins of Godric's Hollow and sighed.

"Always another disaster, eh?" he said to himself, a touch of sadness in his tone, and made his way inside through the destroyed door.

The first body he came across was of James Potter, who to the Doctor's eyes had tried to prevent whatever had entered from getting at his family. The Doctor kneeled down to examine him.

"Not long dead," he said to himself, closing the corpse's eyes. "I'm sorry."

Then he heard a baby crying. He whipped his head towards the sound and made his way up the creaking stairs two at a time, mindless of his own safety. As he entered the room where the child was crying, he saw another corpse. A red headed woman, Lily Potter. It was clear that she too had sacrificed herself to protect her child. He sighed, and closed her eyes.

"Why am I always too late?" he asked, standing up and looking at the baby. The baby boy had black hair, like the man downstairs, and green eyes, like the woman in here. Plainly the couple's child. He lifted the baby out of his cradle and cradled him, quieting the baby that was giving him an intense stare.

"What did this?" he wondered, extending all of his senses to get a psychic imprint of recent events. He winced as he heard the last exchange of the woman and the being that murdered her and husband, and judging by the jagged scar on the baby's forehead, had tried to kill the baby. And he recognised the spell used. "Them again," he muttered darkly.

"Now, who are you then?" he asked. The baby cooed back at him.

"Harry James Potter? That's a nice name. And your parents? I mean, what do other people call them?"

"Lily and James? Well Harry, I'm the Doctor," he said. The baby cooed again, and the Doctor looked sorrowfully down at the woman.

"No, they're… gone. Sorry. Is there anyone who might come for you?"

Another cooing noise.

"You don't know? Well, I'd better leave a message then," The Doctor said, shifting the baby onto one hip and pulling out white pen. He wrote in neat letters on the wall: 'Harry James Potter is now a ward of Merlin and is in the care of a good family. Don't bother looking for him. He'll attend Hogwarts in time'. Then he put the pen away and reached deep into his bigger-on-the-inside pocket to produce a seal that would confirm this, and branded the mark on the wall below the writing. He pocketed the seal, bent down and picked up Lily's wand, and with a word summoned James', pocketing them. He took the baby in both hands again.

"Come on Harry. I have just the right parents for you. Your new mum will even have red hair!" he said with a grin. Harry cooed his approval, then went to sleep. The Doctor smiled tenderly, and made his way downstairs.

Meanwhile, on Demon's Run, River turned to her parents, having dropped off Jenny and Madame Vastra in the 19th century with thanks.

"Are you going to take us back?" Amy asked, still trying to get over the fact that the Doctor's wife was her daughter.

River smiled. "Not yet."

"Why?"

"Because the Doctor's bringing my big brother. Or is he my little brother? It's so hard to tell with Time Travel," River said.

"What is he doing?" Rory asked, puzzled.

"The TARDIS, that wonderful old machine, took him to a baby who had just lost his parents, and needed some love just like I did, and wouldn't have got it otherwise," River said, as the TARDIS landed exactly where it had left from. The Doctor exited the TARDIS, carrying a sleeping baby.

"I hate flying with a baby, I always have to put on the Blue Boringers," he muttered.

"Doctor, who is that? Have you just kidnapped someone's baby?" Amy said, voice heavy with suspicion.

"His name is Harry James Potter. And he has no one. I found him in the burnt out ruin of his house in 1981. His parents were murdered by magic when they tried to protect him, and judging by the cut on his forehead, tried to do the same to him. An ancient protection kicked in, the TARDIS followed it and I decided he needed a home, and who better than you two?" The Doctor said.

Rory looked at River, who nodded. This was her brother.

"We'll take him," he said, and when Amy looked at him, he added, "if Melody, well, River, is found, then she'll have a brother to grow up with."

Amy looked thoughtful, then reached out and took Harry. He snuggled against her, and made a little noise of contentment, and Amy found herself smiling genuinely.

"He's a right little charmer isn't he, that brother of mine? All sorts of people love him on sight," River said fondly, stroking gently at Harry's hair as he slept. "Of course, he learnt from the best, and had a fair amount of natural talent. I'm not sure if Jack's a good or a bad influence."

"How old is he?" Amy asked, absorbed in Harry. "And did you say magic?"

"About a year old. I've got his birth certificate in the TARDIS, along with a few things to remember his real parents by when the time comes," the Doctor said. "And technically it's not magic, it's just really advanced science. Basically, a certain amount of humans have a mutation in their DNA that gives them latent psionic powers, which also occasionally crops up randomly in the rest of the population, creating Witches and Wizards. Long term time travellers tend to develop it over time but rarely does it manifest, so you should develop some latent ability, particularly around him. His parents were a witch and a wizard."

"When the time comes?" Amy queried, passing Harry to Rory.

"When his abilities manifest, as they almost certainly will, and he'll go to a school to get them trained. I'll get you a whole bunch of books on the subject, so you can read up on it," the Doctor said, making a mental note to only get one's written before 1980. "Come along Ponds, Potter. River, until next time."

"I look forward to it sweetie," she said with a grin. "Look after my brother for me."

Meanwhile, Sirius Black dashed into the House. He panicked on seeing the dead body of James, then sprinted up the stairs, being confronted with the sight of a dead Lily Potter and an empty cradle. He fell to his knees and wept.

"I failed them," he sobbed, then the words in white caught his eye. He read down and swore in shock. The seal of Merlin had been used for the first time in 900 years. He scrambled to his feet and apparated to Hogsmeade. Dumbledore had to hear this.

When he got to the gates of Hogwarts, Dumbledore was already there and he looked furious. There were many reasons why Dumbledore was one of the most feared men on the world. One of them was his incredible intellect. Another, Sirius reflected as he was lifted into the air violently with all his limbs out like a starfish, was that he could make your insides become your outsides very quickly.

"Why did you betray Lily and James, Sirius?"

"It wasn't me! Peter was their secret keeper!"

Dumbledore's eyes narrowed. He motioned Sirius to go on.

"We figured that if Voldemort figured out they were using the Fidelius, everyone would immediately think it was me, and no one would ever suspect Wormtail, so if I broke under torture I couldn't give away their location," Sirius explained, tears running down his face. "Now Harry's gone and my friends are dead. Wormtail betrayed us. Use Veritaserum if you want."

Dumbledore looked at him, then Sirius winced as the other man's legilimency sifted through his thoughts. Then he dropped Sirius and summoned his wand, pocketing it.

"You have earned my trust before now. Don't betray it. Now, tell me as we walk, what did you find at Godric's Hollow?"

Sirius poured out the whole thing, the ruins of the house, the disappearance of Harry and the writing on the wall and symbol.

"It was Merlin's insignia Dumbledore, I'm certain of it. No one in history has ever dared use it, and you know as well as I that Merlin was a time traveller of some form," Sirius said.

Dumbledore nodded. "I don't doubt you. And I would advise that you don't bother looking for Harry. I know Merlin and I can tell you that Harry will attend Hogwarts in time. If my guess is correct, he will be raised by one of Merlin's travelling companions, and Merlin always had excellent taste in friends, and will be as safe as can be. There is one person who knows Merlin better than I, if you want to find out more."

"Who?" Sirius asked, trying to get his head round Dumbledore's calm acceptance and claim that he knew Merlin.

"Jack Harkness. He travelled with Merlin, and tells me that he calls himself the Doctor and isn't even human," Dumbledore replied.

Sirius scoffed.

"I wouldn't mock Sirius. You know as well as I that Captain Harkness is rarely wrong about things of an extraterrestrial nature, and if Merlin is indeed not human, as has been suggested by accounts of his face changing at intervals, then it would explain much," Dumbledore.

"Albus, much as Jack is a great friend and a valuable ally, you know that he can talk your leg off and has to be making up at least half the stories he comes out with," Sirius said. "No wizard or witch has encountered Merlin since Camelot fell."

"No witch or wizard," Dumbledore agreed. "And I always got the impression that Jack has issues with Merlin, issues that are impossible to fake. I think he loves him and hates him in equal measure, blaming him for his… condition and abandonment." Only the Marauders, Alastor Moody and Albus Dumbledore knew Jack Harkness' secret, having seen him impaled by rubble caused by a wayward blasting curse, then getting up with no damage except to his clothing.

"If I was in Jack's position, and I was as old as he says he is, I would too. He's older than you are Albus," Sirius said grimly.

"And he does not look it. Sirius, if you prove me correct and are not guilty of betraying Lily and James, talk to him and lay low for a while. I will deal with Pettigrew," Dumbledore said.

When Sirius opened his mouth to protest, Dumbledore replied, "He will be expecting you, and everyone believes that you were the Potter's secret keeper. He will try and use that to his advantage."

Sirius sighed. "Fine. One thing you should know is that he's an unregistered animagus, a rat. We all were, we learnt at Hogwarts, me, James and Peter. I'll show you."

He shifted to Padfoot, then shifted back.

"Remarkable," Dumbledore said, smiling slightly. "I am not sure whether Minerva would be more angry or proud. And I remember her telling a tale of a large black dog that kept chasing her." He added, his eyes twinkling. Sirius had the good grace to blush.

One careful interrogation via Veritaserum later, with a teary Professor McGonagall and Professor Flitwick witnessing, Sirius was cleared of all involvement.

McGonagall on learning that Peter was the traitor was almost spitting with fury. But it kept coming back to Harry.

"But where is he Albus? Where has Merlin taken him?"

"The more pertinent question since Merlin is involved, Minerva, is not where, but when. The only person who has a hope of guessing is Jack Harkness, and even if he knows, he may not say, for several reasons, one being his loyalty to Merlin, even if he knows him by another name. Another reason is that aside from Merlin, the best protection Harry could have would be with Lily's sister as Jack well knows, behind blood wards, and a worse set of parents for any child, let alone a magical one, I could not pick," Dumbledore said. "Never fear. He will attend Hogwarts in time, and be well prepared and protected when he does."

Sirius reluctantly dropped it for the time being. He had to grieve for the friends he had lost.

The next ten years passed in a blur. The Wizarding World partied like there was no tomorrow and everyone speculated on just why Merlin had turned up to take Harry, if it had even been him, with answers varying from the sensible (abroad) to the downright mad (Avalon) and why Peter Pettigrew had betrayed the Potters (he hadn't expected Dumbledore, and had wet himself when the older wizard bound him). Sirius Black tirelessly searched for even the tiniest scrap of news about his long lost godson, rising in the ranks of the Aurors as he did, being seen as the rising star of the department alongside Kinglsey Shacklebolt.

And all the while Harry James Potter grew up as Harry James Williams, and lived a normal, happy life with loving parents on the edge of London. A little brother followed when he was three, Jack Michael Williams, and then a little sister, Evelyn Anne Williams, when he was five. He grew up well aware of the supernatural, which admittedly was fairly hard to miss when your time travelling brother-in-law and big sister popped in for visits and your adoptive parents (not that he knew that they were not his parents by blood yet), worked for UNIT.

When he was eight, after an incident in which one of the school bully's abruptly turned green after picking on Jack, he was told what he was, a wizard, and taught about the Magical World. Jack and Evie also began showing signs of magic as they grew older, with what was later referred to as the 'Night of the Flying Orange Hamsters', being something of a clue.

Then a letter came through the door, just before Harry's eleventh birthday.

"Mum, Dad, I've got a letter," he called.

"What's it about, sweetie?" Amy called back.

Harry wandered into the kitchen, opening it.

"I've been asked to attend Hogwarts!" he yelled, skim reading the letter.

"That's great, can I see?" Amy asked, and Harry handed her the letter. She read it, re read it, then nodded.

HOGWARTS SCHOOL OF WITCHCRAFT AND WIZARDRY

Headmaster: Albus Dumbledore

(Order of Merlin, First Class, Grand Sorc., Chf. Warlock, Supreme Mugwump, International Confed. of Wizards)

Dear Mr Williams (né Potter),

We are pleased to inform you that you have a place at Hogwarts School of Witchcraft and Wizardry. Please find enclosed a list of all necessary books and equipment.

Term begins on 1 September. We await your owl by no later than 31 July.

Yours sincerely,

Minerva McGonagall

Deputy Headmistress

"We're going to need to call the Doctor," she said. "Neither I nor Rory know where this is."

"What about River?" Harry asked.

"If your sister wants to be there, she will. Unlike the Doctor, she usually gets the right decade. And country. And planet. And solar system," Amy said dryly, and Harry snickered.

Then Amy's expression took a turn for the solemn, and she hugged Harry. "When your father gets home from fending off Torchwood, we need to talk. Don't worry, you're not in trouble, it's just important." Each week, Amy and Rory alternated fending off Torchwood duties, though Rory did it whenever Yvonne Hartman was likely to be involved, since Amy had pummelled her into unconsciousness when the woman had suggested that Harry was alien and therefore Torchwood's to do as they wished with him.

When she came round, Brigadier Lethbridge-Stewart coldly stated that any move in any way against Harry or the Pond-Williams family would be met with UNIT's full military and political might. Since the Brigadier had once calmly obliterated at least 5 million hibernating Silurians because there was a good chance they might have been a threat, and half the heads of state in the world either owed him favours or were old friends or both, including the entire UN Security Council, no one was particularly inclined to irritate him over much. After that, Torchwood tended to avoid dealing with Amy or Rory, and their operatives were always carefully polite when they did.

Harry found his brother and sister and showed them his letter, leading to predictable cries of, "Mum, why can't we go? Why does he get to go to magic school and not us?"

"Because it takes students at 11. You two might go in a few years. If you're very good and they choose to take you," Amy replied. "Now go on, it's your bedtime. Brush your teeth and Dad and me'll be up in few minutes. We have some things to talk to your brother about now he's going to magic school, ok?" Amy said firmly.

"Yes mum," the chorused grumpily, trooping upstairs.

Harry curled up in the armchair in the living room as Amy went to fetch something. She came back and handed it to him.

"Before you open this Harry, you need to know a couple of things. First, that you are our son, and we love you so much, and second… you came to us the day River was born. Some very bad people kidnapped her and the Doctor went to find her, but the TARDIS focused on something else. You. The Doctor found you in a burnt out ruin, and your birth parents were," Amy took a deep breath and squeezed Harry's hand, "dead. They died bravely defending you from a very evil wizard. The Doctor made you his ward, and gave you to us to raise as our own." Amy smiled and pulled Harry into a hug, and Rory hugged him from the other side.

"We loved you from the moment we saw you," Rory said, "And we are proud to be your parents."

Harry blinked a couple of tears away, then just hugged them tightly.

"Thanks, but I sort of guessed," Harry said with a wan smile.

"How?"

"I had dreams. Dreams of a red headed woman, just like you mum except not, and a monster. They argued and the woman stood between it and me. Then i-i-it killed her and I remember some green light and a sound of rushing air. The next thing that happened was the Doctor picking me up and talking to me, then the dream ends," Harry said quietly, crying a little and cuddling up to his parents, who both hugged him tight.

"Aw sweetie, you should have said," Amy said comfortingly.

"Only River calls me sweetie, and that's only because she refuses to stop. I'm almost 11 you know," Harry said in a muffled voice, full of affronted prepubescent male pride.

Amy giggled. "Come on. There are some things in the box that you should see."

Harry opened the box. Inside was a pair of wands, a photograph album and a picture from an ordinary camera. Harry picked up the picture, which was a picture of the words 'Harry James Potter is now a ward of Merlin.' He put it down, then picked out the final object, a note.

It said the following:

Dear Harry,

If you're reading this you're probably eleven or almost eleven and about to go to Hogwarts. It's a place like no other and you should be very happy there. You're technically a ward of Merlin (me), to explain the photo. Yes, I am/was/will be (sometimes I hate the limitations of English!) Merlin, court wizard to King Arthur. On your eleventh birthday, I'm sending an old friend of mine, Captain Jack Harkness, who knew your birth parents very well, to show you round the Wizarding World. He's a wizard and time traveller like River and me, and he will almost certainly flirt with your parents and River. It's just the way he is, so try and persuade your dad not to skewer him (not that it would bother him for long). I could go on and on and on, but I won't. The photograph album is from your birth parents house, and those are their wands. They were called Lily and James, and they were very brave, and I reckon that they would want you to be happy.

All my love to Amy and Rory,

The Doctor (Merlin)

Harry read the note, then passed it to Rory and Amy. Amy snickered and Rory rolled his eyes.

"River wasn't joking when she said he was always the good wizard in stories, was she?" Amy said.

"No, she wasn't," Rory said absently.

Amy turned to look at her husband, as did Harry. Rory noted that even though Harry wasn't their son by blood, he was just as good at piercing looks as Amy. "What is it Rory?" Amy asked.

"Oh, nothing. I just remembered the name Jack Harkness from somewhere…" Rory said, before snapping his fingers. "Of course! He's the rogue Torchwood agent. The Brig mentioned him. He's part of Torchwood 3 and actually tries to talk to aliens instead of killing them on sight and dissecting them."

Harry wrinkled his nose at the mention of dissection. "Ew."

"Hey mister, you don't know 'ew' until you've been vomited up by a gigantic space whale," Amy said.

Harry looked at her. "Really?"

"Really. My first trip with the Doctor and I end up covered in alien vomit. In my nightie," Amy complained, and Harry giggled. He cuddled up to her and impatiently beckoned Rory over, hugging them both.

"Love you mum. Love you dad," he said, yawning and going to sleep. After a few minutes, Rory lifted him gently and carried him upstairs to bed.

And for the moment, all was quiet.