Disclaimer: did Harry, Hermione, or any of their friends in canon ever ask the Room of Requirement for a place to understand how the Room itself worked? If not, Harry Potter belongs to JK Rowling, and this story is entirely non-profit. xxxx xxxx xxxx
"Come on Harry, you must have some juicy and embarassing details to share with your Godfather after being 'friends' with three girls for that long." Sirius' knowing grin made Harry go as red in the face as Ron usually was, not to mention wanting to magically vanish on the spot. Why couldn't he have learned the Disillusionment Charm as well as Tracey? And why did he always keep the Invisibility Cloak in his trunk rather than take it everywhere? They'd be great help in avoiding shameless Godfathers, let alone the vast majority of the student population he had reasons to avoid more often than not.

"You got the mousy brunette who loves animals, is good at household magic, and could teach you a thing or ten about being sneaky and causing trouble," Sirius went on despite his Godson's protests, counting with his fingers. "You got the tall, high-society, gorgeous blonde heiress if you don't mind being bossed around - and some people even like it" here he winked at Harry, renewing his huge blush "and you got the muggleborn girl with the brains and the scary talent at magic, which is a bit of a family tradition." Sirius sighed dramatically then, as if lamenting a great loss. "Too bad you don't have a fiery, athletic redhead for the full set - oh, wait! Doesn't your friend Ron have a sister? Fabulous looks and likes Quidditch from what I hear - can't go wrong with that combination."

"Sirius!" Harry yelped, then looked around furtively to make sure they were still alone. If anyone had overheard the subject of their discussion he'd never hear the end of it. Fortunately, he and his Godfather had met on the derelict wooden bridge beyond the Clock Tower, a place rarely frequented by students since it didn't lead to anywhere important. The view of the ravine beneath, coupled with how worn the wooden construction was might have something to do with it, too. "Could we... err... talk about something... anything... else?"

"Seriously?" The tall, grey-eyed wizard with the long, wavy black hair, expertly tailored black robes, and knee-high dragon-skin boots frowned. "I am either losing my mind, or something's wrong with the newest generation. Girls were the only thing James and I were really interested in at your age - them and Quidditch."

"Gee, what else could possibly occupy my mind," Harry retorted, channelling one of the girls Sirius had just mentioned "it's not as if I've been forced to participate in a deadly contest way beyond my abilities... oh wait, I have!" For a moment, he could have sworn he saw both fear and anger twisting his Godfather's face into something ugly, but then the moment was gone and Sirius was as carelessly happy as he'd been since his recovery from the Dementors.

"From what I've heard and seen, you handled the Tournament well enough so far," he said mildly. "As long as you're confident, aware of the risks, and prepared, the Tournament shouldn't be terrible... especially if you pull off a few more crazy plans to keep things interesting, eh?" When Harry failed to react to those dubious words of encouragement, Sirius pulled him into a bone-shattering hug, then pushed him at arms' length and met his eyes, more solemn than Harry had even seen him. "This whole thing's a bad business, Harry, but you aren't alone. You have your friends, your teachers, me - there's loads of people doing their best to keep you safe."

"I know." Harry scowled, his eyes refusing to meet Sirius' pale orbs. "It's just... sometimes it doesn't feel like it, you know? Every year there have been these crazy situations, and every year me and my friends got involved. And always, always there's other students, teachers, even the Ministry who won't listen, or who'll take things wrong, or who'll be gone and we'll have to solve things ourselves. It's..." he trailed off then, leaving the sentence unfinished. Sirius seemed to have heard the ending all the same for he again embraced him fiercely before speaking.

"It's not fair that you've had to go through all those dangerous and scary situations. Guess what? Life isn't fair - my own ten year vacation is proof enough." Sirius gave him an encouraging smile that somehow seemed more real and powerful than any other time Harry had seen him smile. "But Harry, that doesn't mean you don't have people that care for you very much. It might not look like it right now, but Dumbledore, the Hogwarts staff, even the Ministry are working hard to keep you safe. Your friends are there for you, even though their own problems might occasionally overwhelm them. And I will always be there for you... even when you don't see it."

"The not-seeing-you part is becoming annoying," Harry said, happy at his Godfather's words despite his own protestations. "Where do you vanish to all the time? You're nowhere around!"

"Ah, that!" Sirius replied with the air of a man about to divulge one of the great mysteries of life, the universe, and everything. "A curious case involving many Concealment Charms, late-night walks under the moonlight, and the gorgeous sister of a famous Quidditch player..." In the end, Harry had to run for his life only halfway into Sirius' explanation, or at least to preserve his dignity. Then and there he could have sworn he had been the adult and Sirius the irreverent teenager... which was a scary thought indeed.

xxxx xxxx xxxx

Sirius stared at his godson's retreating back until it vanished into the Clock Tower courtyard, then sighed. For all that he'd wanted to protect Harry, to shield him from the many dangers in his path above anything else, he knew that there were some things he could not or should not tell him. His secret missions from Dumbledore were one such thing. The situation he'd found himself in was another, if only for Harry's own good.

"You can come out now," he spoke up in the middle of the empty wooden bridge, his gaze falling at a certain place between two wooden beams where the old roof sagged a little. For a few seconds nothing happened, then a patch of empty air seemed to shimmer, a ratty old cloak moving aside to reveal a tall Gryffindor boy with blond-brown hair, and a short brunette in Slytherin green and silver.

"How did you know where we were?" Tracey Davis demanded, almost reluctantly handing over the somewhat worn invisibility cloak at Sirius gesture. "We were under silencing charms, aversion compulsions, a fairly decent secrecy spell, an invisibility cloak, and a Disillusionment Charm to cover where the cloak had started wearing off. How did you notice us?"

"A decade's worth of experience in both stealth and tracking," Sirius told the teenage witch. "Plus I have certain... advantages. The nose always knows."

"Eww..." the girl almost recoiled at that hint. "You cast a Supersensory Charm on your nose?! That's, like..."

"Never mind that now," he interrupted before she could go on, or the Longbottom boy could join the conversation. "Did you succeed?"

"See for yourself." Davis' smirk turned positively nasty as she presented him with a small glass vase, hermetically sealed. "Didn't even notice us coming; I silenced and disillusioned the vase in advance. Made it unbreakable and covered it with spell-resistant varnish too, just in case. Not that she paid any attention to us - too busy eavesdropping on you and Harry."

"Preparation is important," Sirius nodded sagely then picked up the offered container, glaring at the fat green beetle within.

"One privacy-violating, law-breaking, libellous journalist in illegal animagus form, slightly used," Tracey noted with a hint of pride. "What will you be doing with her?"

"That's for me to know, and for you to fantasize about," Sirius quipped, making the young Slytherin giggle and her companion's face to turn crimson. "Miss Skeeter and I are going to have an enlightening conversation, and you can borrow my spare invisibility cloak for up to three six-hour periods, as agreed."

"Thank you for the help, Mister Black," one or the other teen said but Sirius didn't pay them any attention. He was too busy calculating how long he could keep Skeeter in the sealed jar without the little green bug of a reporter dying of asphyxiation... xxxx xxxx xxxx

Valeria waited in an abandoned classroom on the fourth floor, behind several layers of secrecy spells and with half her attention on the detection charms making sure she was entirely alone. She'd put considerable thought on how to best use Dobby's not-so-little revelation; it was too important to risk being found out early. Thus, when the wall she'd been staring at split and twisted into a lightless passage just large enough for her, she lost no time in internal debate and walked into it at once. A few seconds later, the passage's entrance slipped - almost melted - back into a wall and total darkness fell on the interior. Fortunately, there were spells one could use to see in the dark, and the short, blonde Slytherin had cast one of them before even breaking curfew to come to this part of the castle; it had been far better for subtlety than a wand-light.

After a few hundred steps and several changes in direction that should not have been possible in Hogwarts' normal layout, she came upon another wall that momentarily split into a door as well. Passing through, she found herself in a massive library. Not the one covetously presided over by Madam Pince, the castle's rather peculiar old librarian, but a large, empty, high-ceilinged room full of countless books, tomes, grimoires, and manuals, most of them worn with age and far less well-kept than any book under Madam Pince's care. It would appear that Valeria had discovered a secret library. Appearances, however, could be deceiving, and the room she'd just entered was a far greater work of magic than any library.

When Dobby had first introduced it as the Room of Requirement, or the Come-and-Go Room, her curiosity had been piqued. A room that could become almost anything those entering asked of it? That could not only rearrange its interior, but provide equipment and substances of all kinds per the entrant's wishes? How could such a room work? As with any other wonder of magic, Valeria had wanted, needed to know. And thus the room had first appeared to her as a small, cramped study with a single chair, a desk, and dozens of tomes about some very specific subjects. She'd read them of course, or tried to. Three quarters of the books had been centuries old and written in either Old English or Latin, and the few note-filled folders among them were even harder to decipher. The gist however had been clear enough from the subjects present; variable transformations, layered spatial expansion, and personality investment. Variant transformations were the simplest subject; Professor McGonagal had even shown a few examples in class. To make animated objects wizards had the option of animation charms that conferred perpetual motion, or through complex transfigurations that could move things by changing their shape; the giant chessboard back in first year had been one such. As far as she could tell, the Room had a similar but vastly more powerful and complex spell cast upon it, one that let in reshape its interior to just about anything possible via Transfiguration.
Space Expansion Charms were more Valeria's area of expertise than Transfiguration, but no student, no matter how brilliant, could have fully understood how layered, optionally activated space expansion not only made the room bigger inside than the outside, but also let it change sizes. Not to mention the small fact that there was more than one extradimensional chamber tied to the same magic, as some spaces the Room of Requirement seemed to be always using, even if they weren't tied to the entrances at all times.
But the heart of the Room, what allowed it to function? She suspected a simpler version of the same Mind Magic that made up the Sorting Hat, or the Mirror of Erised. Not much in the way of personality, or deeper analysis of people's characters, but more than enough to read their desires and match them both with a shape and the equipment needed to fulfil that desire. For all intents and purposes it was a magical search engine that made any library catalogue, electronic database or even the recently invented web crawlers look like crude, stone-age tools in comparison. It had enormous potential as both a teaching tool and a repository of knowledge... and it had been created over a thousand years before.

Why was such a marvel hidden, rather than used to teach, or even reverse-engineered to be applied to wizarding homes? Had it been concealed by the Founders themselves, or had it been well-known in ages past, only for the knowledge to be lost by unforeseen circumstances? Valeria had seen the Room of Hidden Things, where generations of students must have left behind their own secrets, experiments, and possessions. Many had to have known of the Room's existence - the elves certainly did. And yet, not once had it been mentioned in any book, or even as a rumour. Her own first idea had been to keep it a secret for her own use... did that indicate some sort of spell that ensured the Room's secrecy indirectly? Valeria resolved to share the Room's existence with her friends as soon as practical. There was only the question of how to keep her own secret projects from them, but she had several ideas about that.

The only thing she was waiting for was the return of her Time Turner later in the week. Until then, she could pass the time reading many obscure books on subjects that had been thoroughly scoured from the Hogwarts library...