Trabenum: creates a mild wind tunnel.

How bad could it be? Ron thought. He rolled up his sleeves and waved his wand.

"Trabenum..." he whispered, and the entire library thundered and shook.

"Ron!" Hermione yelped. Three windows across the room from Ron shattered into the room and the window behind him shattered outside. For half a second, he experienced an immense wind power before his chair flipped back and his head hit the wall. The wind stopped after a few seconds. Ron pushed himself up and the room spun around him. He glanced at the carnage and vaguely saw Hermione waving her wand at the rubble. Something about her face told him she was yelling at him, but all he could hear was a loud ringing.

He stepped into the hallway and Hermione's angry scream suddenly found its way through the ringing and bounced back and forth inside his skull. Clutching his left hand to his forehead, he kicked the bathroom door open. He ran the tap and splashed cold water on his face. As he started to regain his senses, his nose caught the smell of freshly cut grass. For a second, he worried he banged his head too hard. This bathroom was nowhere near any grass. But as the throbbing pain in his head eased up, he splashed water on his face again and walked back to the library.

His desk was now buried in a pile of dust. Hermione was consoling Irma, the librarian, who would lose her temper over anything louder than a whisper. As the first magical research team at Hogwarts, Harry, Hermione, and Ron went through books, artifacts, mysterious spots around the school, and a lot of sophisticated magic. Since Hermione exptected accidents, she insisted that new spells be tested in a safe place. Ron knew he made a mistake but wasn't ready to deal with it.

Ron moved his eyes away from his battered desk and caught Harry smirking at him.

"Glad it wasn't me this time."

"As you should be ..." Ron said and tapped his wand on his desk to clear away the dust, picked up a notebook and a piece of parchment and put them under his left arm. He turned to spot Hermione and walked over to where she sat next to Irma. Irma's face showed nothing but fury.

"I'm sorry Ms. Pince. This won't happen again. I promise." Irma didn't move a single hair. Ron glanced to his side and locked eyes with Harry. Harry nodded. Ron didn't know what Harry meant. But before he could think about it any further, Harry spoke.

"Ms. Pince," Harry's voice sounded unexpectedly giddy, "me and Ron wanted to surprise you with this later, but I guess It's time." Irma tilted her head up, suspicious of Harry's intentions. Hermione squinted at Harry's words. She couldn't think of anything that Harry and Ron had worked on together lately.

"Ok. Stay where you are," Harry ran to the other side of the library, further upsetting Irma. She insisted that one must move gracefully in the library at all times. Harry realized what he did when he saw Hermione shaking her head on his way back.

"I hope you don't kill me before you see the results," Harry expected at least a chuckle, but he got none of that. "Let me demonstrate," he opened the book he brought back with him to a random page and held his right hand to his chin, as if thinking about something.

"Ron, do you remember the spell you found that did nothing?"

"Which one?"

"The one you cast on Marvels of Dark Architecture," Harry chuckled. At that, Irma's face turned a velvety shade of red. Casting a spell on a library book was unforgivable. She was only bidding her time before the silly display was over. How can they not know what bothered me after all these years? Are they really that stupid? No. They will not be forgiven for this.

"No way! You got that to work?" Ron was oblivious to Irma's rage, and so was Harry.

"Behold…"

Harry paused for a few seconds without moving or saying anything.

"Page seven hundred. That's a suitable number."

"For what?" Ron asked.

Harry grabbed the open page and ripped it off. Hermione gasped and Irma stood up in shock, her face now a deep shade of purple. Harry held his ground and tossed the ripped sheet into the air. Irma opened her mouth, completely losing her temper, but she froze in the middle of the first curse-word she intended to utter. She searched for the torn page all around, up in the air, behind the nearest shelf, but it wasn't there. Her mouth slowly closed and she remained silent. She turned back to Harry and saw a smug grin on his face. His index finger pointing to something on the page. Irma reluctantly peeked. Page seven hundred. Perfectly intact. Now she was completely frozen, on the edge of tears. Irma's face exuded a full rainbow of emotions.

"Harry! How did you do this?" Hermione beamed. This gave Irma some time to get herself together.

"Oh you know…" Harry said.

"I don't, actually..."

"How easy is this to reproduce?" Irma interrupted with a shrill voice..

"A wave of a wand…" Harry smiled.

Irma could barely control her emotions, so she lurched forward and pulled Harry into a rib-crushing hug.

"You don't understand how great this is," Irma paused, a small tear forming on the edges of her eyes. She turned to look at Ron, a warm smile on her face, "please don't wreck my library again," and she spoke with a gentle voice Ron hadn't heard before.

"I won't," Ron smiled.

"I'll have to leave now. I trust you three will handle the cleanup," Irma said as she walked away, not waiting for an answer. Those brats will wreck my library again, I'm sure of it. But for once, I hope they do it again. Eternally pristine books... Can it be? It was the best news Irma heard in her entire career as a librarian.

Harry watched Irma walk away for a few seconds. He turned back and saw Hermione holding her arms on her sides and a smile on her face.

"And how does that spell work, if you don't mind explaining?"

"If I tell you, can I skip the cleanup? I'm almost late for my students," Harry grinned.

"Fine," Hermione's curiosity forced her to give in to Harry's extortion.

"So I don't know exactly how it works—" Harry stopped when he saw Hermione roll her eyes. "If you don't want to hear it..." He pretended start cleaning up. Hermione grabbed his left shoulder and turned him back to face her.

"Ok I promise I won't say anything," she snickered under her breath.

"The charm binds the book in time, and it only works for books."

Hermione gaped, "woah, That's really impressive, time-turning spells are very difficult."

"Blimey, it's a time-turner?" Ron chimed in.

"I found a detailed description of it in volume four of Chadwick's Charms," Harry continued.

"There's no volume four, so which one was it?" Hermione asked. Harry didn't say anything. He only smiled. Hermione's jaw opened to a full drop.

"You didn't..."

"I did," Harry kept smiling, "I have to go now, I'll show you later." He walked back to his desk in a haste. He stashed his wand in his pocket, a bad habit he never managed to get over, then he picked up his notes and cup of coffee. He turned back and was shocked to see a sparkling clean library. Hermione shrugged. Harry shook his head and walked out the door. Of course, Harry knew that Hermione knew more than most wizards combined. He was amused that he found something she didn't know. He decided that if this happened again, he would try to make it more interesting.

"Thanks buddies!" He heard Ron's voice from the distance. He really came out of the whole ordeal with the least amount of effort.

Harry walked through the quiet hallways. Various wizards on paintings moved around, socialized, and said random things. With class still in session, the hallways were as quiet as they got. Except for the dead of night, when the painting-dwellers went to sleep. Harry loved those moments of silence. They made him feel like an adult. Even after three years as a Hogwarts staff member, he wasn't used to walking the hallways between classes, at night, and getting away with casting dangerous spells without detention. It was definitely his dream job. I can walk over to Hogsmeade without anyone stopping me. It felt good when Harry reminded himself of his freedoms, even though he didn't really have that particular one at that very moment.

He walked up the stairs to the third floor, through the Serpentine Hallway and reached a room with a tag that read, "Class 3C." He shouldered the door open and walked inside a loud and muggy room, full of brilliant-looking young students all speaking simultaneously. The Defense Against The Dark Arts classroom was as dingy as always. Ever since Gilderoy Lockhart's portraits were taken down, the walls had been empty. For the last three years, Harry tutored first-year students in some practical aspects of the class. He helped them develop their Patronuses and improve their stances, among other things. For almost an entire year, Harry visualized Snape waiting behind that door each time he opened it, and it made him nervous and somewhat sad afterwards. But now he knew exactly what to expect. A loud classroom with kids who are mostly clueless, and he loved it.

"Who's toad is this?" Harry pointed at the tiny toad leaping onto the platform.

"Must be Fourfoot's" one of the kids spoke.

"Four whats?" Harry replied without thinking. Everyone in the class laughed. Everyone but one small girl with black hair that covered half her face. Harry could tell she wasn't laughing because she was dragging her feet to the front of the classroom. She leaned down and picked up her toad. Then she looked up at Harry.

"I'm sorry Mr. Potter." Couldn't he have picked Bathilda up himself?

"What's his name?"

"I— " Fourfoot seemed a bit taken aback by the question. "Her name is Bathilda." The students laughed again. Harry wanted to ask Fourfoot for her real name, but he didn't want to give the class another reason to laugh. He nodded at her and she scampered back to her desk. Harry knew better than to interfere, no one liked a teacher's pet. And he wasn't even a real teacher. He asked for the toad's name but not mine. So he is a bloke just like the others. Only the blokes are all about the stories, so it adds up after all.

While Harry was in class, Hermione went on her daily afternoon trek around the castle. She took long, slow walks and surveyed walls, roofs, and various structures for any valuable information. She copied inscriptions written on stones, statues, and walls. She measured distances between objects and buildings and drew detailed maps of walkways, landmarks, and staircases. It had been many months since Hermione found anything new. What exactly do I hope to get out of this? Hermione wondered as she scribbled a note. It's relaxing. My mind is clear after these walks, that's why I do it. It made Hermione feel a little guilty. But I shouldn't. Ron is playing with cups and Harry's playing with kids, why can't I play as well?

As she approached the end of her walk, she passed by the northern edge of the of the great hall, immediately outside the building. Right before she turned toward the front, she glimpsed an unfamiliar stone with the edge of her eyes. She knew the grounds so well that a single misplaced object became easy to spot. She pointed her wand at the stone and spoke the levitation spell, "Wingardium Leviosa." The stone lifted up in the air, revealing a hollowed out inside. A stack of Weasley's Wizard Wheezes products sat on the ground where the stone was. Dungbombs, Weasley's Wildfire Whiz-bangs, and a Weather in a Bottle. Hermione's lips curled in a reminiscent smile. George closed the shop a year before and started doing a one-man magic show called 'The Single Twin.' The name broke everyone's hearts, except for George's audiences, they loved him. Magic shows weren't a big deal before George became The Single Twin, but ever since, copycats and like-minded performers started popping up everywhere. Hermione half-heartedly wanted to confiscate the items, but she didn't, she placed the stone back where it was and walked away. For you, Fred. But it would likely be the last time she let something of that sort slide. She was now working at Hogwarts, and a part of her duty was to observe the rules.

Ron was in the History of Magic classroom. Alone. He practiced a spell that would theoretically render objects immovable. Most say it doesn't truly work, including Ron's source. Although rumors say it was used in the construction of some Egyptian tombs, and Roman Aqueducts later in history. He used a porcelain mug as his object, and no matter how he tried to say the word Immobiliamus, the cup would continue to be movable, mocking him. He broke a few cups in anger. Why did I pick this stupid spell? What good would it be anyway? No. I spent too much time on it. And I feel like it should work. Feel.. Nothing more. I'm probably wrong.

Every day, after spending four hours going through new material at the library, Harry, Hermione, and Ron each went their own way for the next hour. Harry chose to help the first-years, Hermione surveyed the castle, and Ron practiced spells he found interesting. On his last attempt at the Immobiliamus spell, he pointed his wand at the cup and yelled out in anger, "Immobiliamus!" but he accidentally touched the cup with the tip of his wand and it exploded in a cloud of dust, signaling Ron to call it a day.

At times, wonderful spells and discoveries kept them very busy. Other times, however, things got really slow. During a particularly slow month, the only valuable thing they got was a spell Ron found that baked potatoes in an instant. One time, Hermione very safely tried a spell that made everyone within a two kilometer radius very sensitive to light. This prompted professor McGonagall, the current headmistress of Hogwarts, and a number of teachers to cast spells that darkened all classes and hallways for an entire week.

A few days later, Harry, Hermione, and Ron had just used up their personal hour after the library and they started to head to the staffroom where they shared most of their meals. Hermione joined Harry and Ron a few minutes after they started eating. She rushed into the staffroom with her face red and her mouth stretched into a smile.

"I think I found a secret room," she struggled to catch her breath.

"where?" Ron raised an eyebrow. Can it be?

"There is an empty room next to the scroll-writing workshop with a circular wall. On the outside, the walls go all the way to the ground. There is no way to access the lower part under the empty room..."

"That's a hidden room!" Harry said, "let's add it to the top of our discovery list, sounds like fun." Ron went silent. He didn't know how to handle the excitement building up within him.

Hermione thought about what Harry said for a few seconds, "we still have to get through the spells we found in the Archive of Medicinal Potions, but I suppose we can make time."

"It's decided," Ron announced, his voice filling with excitement, "we have a new mission!"

Despite their excitement, they finished their lunch of roast duck, delicious pie, and some butter bear. Throughout their lunch, they talked with their mouths full and their brains wired. As soon as they finished eating, they cancelled any activity they had planned for the rest of the day and headed to the scroll-writing room. After a few hours of searching the walls inside and out and walking around the castle several times, Ron complained.

"Blimey, this thing is hidden very well. What if there is no room at all?"

Hermione studied his expression for a moment before responding.

"Ron. We knew it was hidden, didn't we?" She said with an impatient look on her face. Ron lowered his head.

"I know.. I was too excited to find a secret latch or something, but this seems much harder, that's all."

Over the next three days, they reduced their reading hours at the library and most leisurely activities and spent their time looking into the room. Hermione found this a good reason to dive into Bathilda Bagshot's Hogwarts: A History. She learned a lot of things she'd missed the first fifteen or so times she read the book, but nothing that hinted at the hidden room. Harry and Ron kept searching their own way whenever they had time, but no new clues emerged. So they continued to search whenever they got a chance.

On the third day, Hermione spotted professor McGonagall heading into the Hogwarts building. Which was increasingly uncommon since McGonagall became principal and assumed a ton of responsibilities.

"Professor McGonagall!" Hermione called, "I've been meaning to find you."

McGonagall stopped and looked at Hermione, raising her eyeglasses a bit.

"Ms. Granger," McGonagall smiled, "I heard you've been doing a good job around here. And that spell to bake potatoes is an absolute delight." Hermione blushed, but was a bit disappointed that the baked potato was her best credit.

"Thank you professor... That was a slow day."

"What do you need Granger?" McGonagall said affirmatively but kindly. Hermione looked at professor McGonagall with testing eyes before starting. After all, she was looking for a hidden room, and that only brought back memories of a furious McGonagall. But she gathered her thoughts and managed to speak.

"There is a hidden chamber under the scroll-writing room, do you know anything about it?"

McGonagall's face didn't show any changes for a few seconds, making Hermione nervous, but she brought her palms to her mouth and started laughing, then she put her hands on Hermione's shoulders, gasping for breath, her mouth now stretched in a wide smile.

"Oh Ms. Granger, how you three made your passion of troublemaking into a job is beyond me, and the fact that you still manage to find something every week is astounding." Hermione was seriously blushing now, but McGonagall went on, "And I heard Mr Weasley made some wonderful progress in his chase after the fabled Immobiliamus," she giggled.

"He did?" Hermione asked, half surprised and half doubtful.

"Well… He's overcome his anger at the cups, which is good because we were approaching a serious shortage ..." her voice trailed off for a second, but she continued, "and to answer your question, I don't know anything about that room. If you need my help with anything, set an appointment with professor Sprout. Otherwise, please notify me before you open any locks or doors, we don't want another scare in school ... Or worse."

That summed it up for Hermione. She thanked McGonagall and continued her walk back to the staffroom, where she expected to meet Harry and Ron. The hallways were now bustling with students and teachers. And since returning to work at Hogwarts, Hermione never got used to the dozens of young eyes following her every move. Harry and Ron didn't mind it, as Harry was used to it and Ron actually enjoyed it. She made it into the staffroom and found Harry and Ron eating. But as soon as she walked in, Ron started talking, almost choking on his food.

"H,mone, Hy, Room," Ron said.

"Swallow your food first!" Hermione said and waited until one of them talked, which ended up being Harry.

"In Marvels of Dark Architecture," Harry started, swallowing the last bit of his food, "they talk about rooms accessible only to house-elves," he paused, his mouth stretching into a smirk at Hermione's astounded face. She paused, then giggled.

"I never thought I'd see the day when you too were excited about something you read in a book. How times change ..." Her voice trailed off. Harry and Ron looked at each other, smirking.

"Pay up," Harry said, gesturing to Ron to hand him something.

"Blimey. I forgot about the bet," Ron reached in his pocket and placed a single Galleon in Harry's extended hand. Harry smirked, looked up and found Hermione giving him an inquiring look.

"Ron thought you probably already knew about this and dismissed it for a good reason, so we made a bet," he said. Hermione laughed.

"I say we go tonight," Ron said.

"Don't be silly," Hermione said, "we have a ton of things to do today. Also ... McGonagall asked that we tell her before we try to enter any rooms." Ron's face dropped a bit. He got himself too excited about an adventure too soon.

"What did she say?" Ron said.

"She said to let her know before we open any locks..." Hermione rolled her eyes at him, knowing that he'd suggest there were no locks involved.

"Bu—"

"Don't even try Ron," Hermione said affirmatively.

"It's settled," Harry said, "tomorrow we inform McGonagall and get an approved time to go in, we have no other options." Hermione nodded. Ron continued to chew his food in silence, with the face of someone who'd been betrayed, but he was excited on the inside, knowing it won't be too long before they get into that room.

"Kreacher?" Hermione asked.

"I think so. We better call him now and let him know so he can be prepared. Kreacher!" Harry raised his voice when he spoke Kreacher's name, startling Hermione and Ron. A second later, Kreacher stood in the middle of the staffroom with a smile on his face.

"Good to see master Harry!" Kreacher bowed, "and master Harry's friends!" he bowed at Hermione and Ron. All three of them bowed back at him, making him bow even harder.

"How can I help master Harry?" Kreacher looked Harry in the eyes. Harry leaned down to bring his face closer to Kreacher's level, but as he lowered himself, Kreacher lowered himself further.

"Kreacher! Get on your feet."

"Kreacher is sorry. Kreacher has upset master!"

"No... No Kreacher, I only want to talk to you like normal people," Harry laughed, "we need your help to apparate into a hidden chamber at Hogwarts in a few days," Harry said. Kreacher stared, waiting for Harry to add something else.

"We wanted to let you know so you'd be prepared," Hermione broke the silence.

"Kreacher would be happy to help!" His face beamed, "Please call me when you need to go into the room, any time," he bowed as he spoke.

"Thank you Kreacher," Harry nodded.

"Thank you Kreacher!" Hermione and Ron spoke together. Kreacher bowed again and apparated out of the room. Leaving them in silence.

Right after lunch, Hermione requested an appointment with McGonagall. After that, nothing was left but waiting.