1.
It is a common belief that the wards around Hogwarts were crafted by the founders, and wards of such complexity and beauty have not been created since the four young geniuses built their castle.
This is not so.
It is the land on which the castle is built that protects the school and its residents. Said land would still be hidden to this day if the four founders had not stumbled their way into a strange Japanese shop manned by a strange Japanese woman and two strange Japanese children, situated in the middle of London. The woman claimed to be selling exactly what they were looking for.
"What is your price?" asked Slytherin, suspicious.
"Your future happiness and the happiness of all your future children," the woman deadpanned.
Slytherin raised an elegantly arched eyebrow. The woman rolled her eyes.
"They never believe me," she muttered. Then, louder, "I'll take that beautiful snake egg that you're keeping warm in your pocket."
Slytherin hesitated for a moment, but if the woman was telling the truth, it would be worth it. "Be careful with her," he told the shopkeeper, cradling the egg tenderly as he drew it out of his cloak. "Her name's Nagini."
2.
The reason that the curse on the Defense Against the Dark Arts position is so hard to remove is that it is not really a curse at all. Instead, it is a mostly forgotten aspect of the Hogwarts Charter that stated that no Headmaster was to govern the school for over twenty five years at a time. Tom Riddle, one of the only students who ever bothered to talk to the ghosts, intensified the spell and focused it on the Defense Against the Dark Arts teaching post instead.
As a result, Headmaster Dumbledore was the longest reigning Headmaster of Hogwarts School of Witchcraft and Wizardry since its founding. Unfortunately, he was also convinced that it meant that he was the best, and thus he refused to listen to the preposterous claims of the jealous Headmasters and Headmistresses that had come before him.
3.
In her life, Alexandra Trelawney had one prophecy and one child. Until her death in 1979, nobody ever believed either one.
4.
Some prophecies are never known by their subjects, and some prophecies only make sense in hindsight. Over eighty years after the death of his sister, Albus Dumbledore emerged from the Hall of Prophecies and wept.
5.
The location of the Isle of the Blessed is believed to be lost with the fall of Camelot, although every few years a new expedition goes in search of it. The truth is, the location was entrusted by Merlin to a witch called Yuuko, and she sold it a few centuries later to a promising quartet of witches and wizards. Many years later, it is no longer an island, but a hill and a valley overlooking a lake.
The expedition parties always include at least one Hogwarts student, and the irony makes Yuuko laugh.
6.
If Petunia had been born magical and Lily not, the world would have been a little different. Petunia would've been sorted into Hufflepuff, and gain an appreciation for hard work and loyalty whenever her house stood up for her against the Marauders. She would never be able to stand bullying in any form for the rest of her life. James would remain a playboy for all of his Hogwarts years, but after graduating and committing himself to the Order of the Phoenix he would fall in love with a kind woman named Emmeline Vance. Their first child would be born in August.
Lily would move to the States, having a brief career as a Hollywood starlet before retiring to California instead of Surrey. She would live a peaceful life until one day she would go into her laundry room and find a baby and a note. It would say:
"This is Jo. Please take care of her. But beware. This is a DANGEROUS baby."
7.
There was one person who opened the Chamber of Secrets who was not a descendent of Slytherin, and he was expelled for it before Dumbledore was born. He was a proud muggleborn Ravenclaw and a genius—he invented his own branch of magic for investigation and with it he found the Chamber all on his own, conjuring a snake to unlock the entrance for him.
The Headmaster was horrified.
The situation was hushed up and hidden. The boy was quietly expelled with his wand snapped, under the pretence of attacking another student. His name was discreetly wiped from all wizarding records. With nothing more than a few investigation charms left active and a healthy distrust of authority, Sherlock Holmes was left to fade into obscurity.
8.
Of the many practical jokes the founders played on each other, the undisputed finest was the way Helga tricked Salazar into building the entrance to his office in a girl's washroom.
Thankfully, the other founders agreed with minimal bribery to pretend that it didn't exist. Salazar sealed the entrance with parseltongue and struck it from the blueprints.
9.
Hermione can trace her family tree back for five generations of muggle normalacy. A few generations before that, if she knew her genealogy, she would be able to find a squib with the unfortunate name of Gertrude Agnes Ravenclaw. Trace back the line from there and you would eventually find the esteemed Rowena Ravenclaw herself.
Of all the children she attended school with, she was the closest relation to the founders of Hogwarts. Oddly enough, this didn't entitle her to anything.
10.
"Are you sure this is a good idea, Merlin?"
"Of course, Arthur. When do I have anything other than good ideas?"
"The sword."
"Wha— That was the dragon's idea! Have you ever tried saying no to a dragon?"
"Dragon? Have you been at the tavern again? I'm talking about what happened on the training grounds, you numbskull."
"Oh. I didn't say dragon. I said… damn idiot."
"You're drunk. You're definitely drunk."
"Well, at least my shirt's not on backwards, you prat."
"It's not- Merlin, help me fix my shirt, Gwen will be up any moment now."
"….there. And you just misheard me. You're very nervous."
"You sure?"
"I swear on… my beard."
"You don't have a beard."
"Well, if I'm lying, then I'll grow one and shave it off. Now go and take your future queen on a date."
11.
The Malfoy hair-care regime is a closely guarded hereditary secret. Not even Narcissa Malfoy (née Black) knows, so naturally it is a favourite subject of discussion whenever the wives of Death Eater have tea.
12.
The Weasleys are an old, old magical family. They trace their roots back to a time when magic was wilder and brighter and untamed, a pagan pantheon's gift to humanity. They were nobility then, redheads with a penchant for curiosity and mischief, and their lands were known as the fiefdom of Trebond in the country of Tortall. The land the Burrow is built on is what is left of this fiefdom, considerably smaller but no less loved because of it.
Girls in the Weasley family are rare—one of the reasons that the direct line has lasted as long as it has. When they occur, however, they invariably have the same imaginary friend: a black cat with purple eyes.
13.
It is much easier to identify a child of prophecy in magical Japan than in magical England.
Every so often in magical Japan, a child is born with a hair colour that rightfully belongs in a crayon box rather than a human head. Most of the time, the child is a girl. She is treasured and pitied and always forced to grow up too fast—she is destined to live in interesting times, and sometimes to save the world as well.
14.
Harry Potter has always believed that time turners are created somewhere in the bowels of the Department of Mysteries, and stored in the cabinet that he accidentally broke in his fifth year. If he had ever mentioned this to Hermione, he would have been smacked gently on the head with a dreadfully heavy book, and corrected.
Time turners are magical phenomena, as natural as St. Elmo's fire. The Department of Mysteries—and subsequently the rest of the Ministry of Magic—was built around their origin point, where a new time-turner seems to appears every time one is used. Supposedly this would lead to an unending deluge of time-turners, but that it obviously not the case, as time turners also have the tendency to spontaneously vanish when out of view and unused for too long. The speculations behind this are many, but the truth is unknown.
The truth is this: when the number of time-turners in existence reaches a certain limit, some of them anchor themselves to a consciousness and return to an older point in time. The force of time-space magic warps the fabric of reality, and a parallel universe is formed, identical in every single way save for the quantity of time-turners. This happens surprisingly often—every time the ratio of time turners to universes rises above 131313:1
Harry Potter has interacted with time-turners much, much more than the average person—as a result, they are very fond of using his consciousness to piggy-back back in time. Most of the time, everything goes as planned. But sometimes, the time turners bring a piece of his consciousness back as well. Sometimes, Harry Potter remembers.
15.
The statistical probability of a squib being born to a magical parent is the same as the probability of a muggle-born being born to two non-magical parents. Both probabilities increase if the parent(s) have an unconfirmed family history of mental instability.
16.
Dementors are born from genocides. That was the pet theory of Grindlewald, when he recruited them to unleash across Europe. There are no records of a time before dementors existed, so there is no way to prove or disprove this theory. But it's always been a secret pride of Grindlewald that the dementor population of Eurasia doubled during his lifetime.
17.
Glasses in the wizarding world are a purely aesthetic choice, because a simple spell that adjusts light rays can be applied to the eyes and then anchored permanently to any accessory the wearer desires. This is one of the things that all wizarding children know, so naturally Harry Potter doesn't learn of it until he's twenty-one.
Hermione performs the spell for him, asking for nothing but his old glasses as payment. Unknown to Harry, after he agrees she sells them on the black market for around fifteen years worth of her salary.
18.
"Merlin's beard that is one ugly sonuva—"
"Will you please just let it go, Arthur? That was years ago."
19.
Somehow, it seems to be a law of the universe that Neville Longbottom must forget at least five things a day. He never grows out of it when he grows up, but by the time he masters his forgetfulness, he doesn't want to.
After all, for a wizard, the ability to close your eyes and simply choose to forget that something is impossible is a very, very useful skill indeed.
20.
Hufflepuff's favourite colour was green, but Slytherin called dibs.
[END]
I wanted to try writing something in this format. It turned out as an experiment in head-canon and cross-overs. I do not own Harry Potter, xxxHolic, Merlin, The Order of Oddfish, Sherlock Holmes, The Song of the Lioness, or any magical girl anime ever created.