Author's note: This is an AU in which Harry Potter and his friends have been replaced with Dean and Cas and all the SPN cast, so there have been some changes in the dynamics between the Houses. I had the idea for this fic when I saw Lettie's SPN fanart on Tumblr which is seven kinds of adorable. This isn't strictly speaking a fanfic for her universe, since I borrowed many elements but also added and changed several others to fit with the story that I wanted to tell.

Sorry about how short this chapter is, the others will be longer. I wrote it in Italian first and now I'm translating it as fast as I can, which isn't very fast at all.

Chapter 1: Mail from Hogwarts

The letter from Hogwarts arrived at the end of July.

Sammy stared with wide eyes, his spoon halfway between his mouth and the bowl of cereals, while a huge spotted owl dropped two letters on the kitchen table. It was funny to see his brother look so flustered. Dean laughed, and almost choked on a piece of toast.

"Stupid birds," muttered John Winchester, brushing a couple of feathers from his breakfast. "I hope the neighbours won't complain again... Dean, stop making fun of your brother. If I'm not mistaken, when you got your first letter from Hogwarts you were so excited that you almost peed yourself."

When their father left the table to check the eggs and bacon, Dean stuck out his tongue at Sam.

"One of those is mine, isn't it?" Sam asked, too nervous to be upset at Dean's mockery.

"Of course it is, dummy," Dean said. "It's got your name on it and everything. Mr Samuel Winchester, The Small Flat On The Fourth Floor, 2 Hunter Street, London..."

Sam tore his envelope open with shaky hands and started reading the letter. Dean, at his fifth year by now, smirked with superiority and decided to take his time.

John gave him a generous helping of fried eggs from the pan. "Aren't you going to read your letter?" he asked Dean.

"I'm going to finish eating first," Dean said, his mouth full of eggs and toast. "It's going to be just the list of books anyway. I'm not going to become prefect, so whatever."

"That's because you're always getting into trouble," his father said. "This year, you try and behave. You've got to show a good example to your brother."

Dean rolled his eyes. "I don't get into trouble, it's just that Professor Crowley hates me." he said. He refrained to add that Crowley hated him because in his first week of his first year Dean had covered the floor of his office with toad slime.

Before his father could recall that particular incident, he took his letter and opened it.

"It just says the usual stuff," he told his father as he scanned the letter. "The Deputy Headmaster is letting us know that term starts on September 1st, train leaves from King's Crossing as usual, there's a bunch of new books... Oh!" he exclaimed once he reached the bottom of the page.

Sam looked up from his letter, which he'd probably already read three times. "What?" he asked.

"I became captain of the Quidditch team!" Dean exclaimed.

That was the best possible news. Dean was Gryffindor's Seeker, and Quidditch was one of his very favourite things about Hogwarts. He was still upset at the thought of having been defeated by Hufflepuff in the last match and he couldn't wait for a rematch.

"This year we're going to win the Quidditch Cup," Dean said. His brother looked at him admiringly.

"I'm happy for you, Dean," his father said. "Sam, eat those eggs before they get cold. I've got to go to work."

Mr Winchester worked as a mechanic in a garage. He was a Muggle and didn't understand much about Hogwarts and about magic. He had married a witch, Dean and Sam's mum, but she had died many years ago. Dean didn't remember her very well.

Despite his feigned indifference, Dean was happy that Sam got his letter. They were both half-blood, and Sam had spent the last few weeks worrying that he didn't have enough magic to go to Hogwarts. Dean thought that even if it turned out that he was a Muggle, it wouldn't have been too bad: he could have been a mechanic and help John at the garage. But being a wizard and casting spells and playing Quidditch was much more fun.

Dean couldn't wait to go back to Hogwarts. The Winchesters lived in a Muggle neighbourhood, so he couldn't practice magic during the summer holidays. He couldn't even write to his friends very often, because his neighbours would have been suspicious if they kept seeing owls coming and going from his bedroom's window.

Between one thing and the other, Dean had to wait until late in August before John found time to bring them to Diagon Alley to buy their school supplies.

Like every year, John complained about how hard it was to find parking in that part of the city. "It's a pain to get to this pub," he grumbled when they finally reached the Leaky Cauldron. "How does it work, again? Do we have to ask the owner to open the entrance at the back?"

"No need, I can do it," said Dean, who couldn't wait to do some magic. Sammy and his father followed him into the pub's tiny courtyard.

Dean took his wand from the pocket of his jeans and hit one of the bricks of the wall, which immediately opened to reveal the street and all its magic shops.

Sam had never been to Diagon Alley: the other times he was too little and John left him with Pastor Jim while he and Dean went shopping. Now Sam was looking around, his mouth wide open with stupor, and he kept glancing at Dean.

"When I have a wand, will I be able to cast spells like that, too?" he asked his brother.

"If you can learn how to do it," his brother replied.

"Stop bragging, Winchester," said a voice behind him. Dean recognized the speaker as Raphael Milton, one of Slytherin's prefects. "That was just an automatic spell, any half-blood with a wand could have done it."

Dean turned, his face crimson. "Looking for trouble, Milton?" he asked pointing his want at Raphael. "Professor Crowley won't be around to save your sorry arse when I make all of your hair fall out with a curse."

John frowned. "Let's go, boys," he said. He put his hands on Dean's and Sam's shoulders and pushed them away.

As they were leaving, Dean turned back and noticed that Raphael was glaring at his father. Mr Winchester, with his jeans and his plaid shirt, looked very out of place in a street full of wizards wearing cloaks and pointy hats.

Dean was pissed at the thought of Raphael insulting him in front of his father and his little brother. He tried to explain that Raphael was an arrogant bastard who thought he was better than everyone else because he came from a very old family, and that he was in sore need of someone teaching him a lesson, but his father wanted to hear none of it.

"That's enough," he said. "I don't want you to get in a fight. I'm not a wizard, if you get in trouble with your school I won't be able to help you."

He didn't even allow Dean to check out the Quidditch equipment store, dragging him directly to Gringotts. Dean pouted, but his mood improved a lot when Sam gasped at the sight of the goblins.

Mr Winchester changed some Muggle banknotes and received in exchange a small pile of gold coins. "I hope it'll be enough to pay everything," he muttered. Wizard money always confused him.

Between Dean's list and Sam's list, there were a lot of things to buy. Sam was ecstatic when they visited Flourish & Blotts, and it took them forever to drag him away from the books. Then Dean spent some very uncomfortable fifteen minutes on Madam Malkin's stool while the witch stuck hundreds of pins on him and measured him for new school clothes, since he'd grown again over the summer.

Finally they reached their final stop, Ollivander's. Sam was trying to act nonchalant, but it was obvious that he was beside himself with glee at the thought of finally getting a wand.

Mr Ollivander greeted them with a bow from behind the counter.

"Mr Winchester," he said with a small smile. "Ash, thirteen inches, dragon heartstring. A fine wand."

Dean nodded. The shop, dark and dusty and filled to the ceiling with boxes of wands, made him feel uneasy.

"And there's another Mr Winchester," Ollivander continued, turning towards Sam. "Here for your first wand, I suppose."

While Ollivander was taking Sam's measurements, the small bell above the door rang to mark the arrival of new clients. The newcomers were a tall witch with a stern face and a little blonde girl. The witch made a noise of surprise as she stepped inside.

"Winchester!" she exclaimed, turning towards John.

"Hi, Ellen," he replied. If he too was surprised, he didn't show it. "It's been a while since the last time we saw each other." Dean waved a greeting to the little girl, but she ignored him.

The witch nodded. "Are they your sons?" she asked. "They took after her."

"Dean and Sam," John said, pointing to them in turn. Dean was following the exchange with great curiosity. "Your daughter Jo is all grown up too..."

They were all distracted by a huge cascade of silver sparks, and Sam rushed over to tell them that his new wand was made with a special wood, because he was the typical geek who would care about stuff like that. Mr Ollivander wrapped up the new wand (vine, ten inches and one quarter, unicorn hair) with great care and presented it to Sam with another bow and a flourish.

John and Ellen exchanged some more words before saying goodbye, talking so quietly that Dean couldn't hear what they were saying. Before leaving the shop, Dean turned back one last time and saw Mr Ollivander measuring the length of the little girl's left arm.

"Dad, who's that witch?" Dean asked once they were back outside. He had no clue that his father knew people from the magical world.

John lowered his eyes. "She knew your mother," was all that he said, and Dean didn't ask any more questions.