HP: Fairborn Adventures

September 10th, 1976

'It was gone... All of it.'

Harry's eyes traveled over the empty shelves, which had been stacked with unique knowledge, long forgotten by humanity. A large pile of white ash in the corner of the room and scorched stone tiles gave clues as to what must have happened.

Riddle had burned down the entire collection of ancient tomes, including the two latest additions Harry had found in Slytherin's vault at Gringotts. He swallowed the loss as best as he could. Not just because Harry intended to perform a few of the healing rituals, but also because he had been not even close to finishing reading the collection he found down here. 'Now it was too late.'

The giant skeleton of the Basilisk and the barrels outside in the main Chamber had been left untouched. Perhaps, because Riddle did not want Harry to instantly get suspicious about someone being down here and was preparing traps for him? 'It hardly mattered now.'

His eyes flickered over the small desk where he had stored two more vials of Basilisk venom. Those had been taken as well and partly used to lace the arrows' heads from one of the traps. Two vials of the most potent venom on the planet were in the hands of a psychopath in a castle full of children. The thought certainly did not sit well with Harry.

The Chamber had been compromised and Riddle had officially declared war on him. Harry desperately needed some counsel. Luckily the heavy bag on his shoulders reminded him that at least he had been smart enough not to leave his ancestor's tome down here. 'That loss would have been almost unbearable.'

"We have a problem." Harry opened the tome and dropped into the wooden chair next to the old desk: "A very serious problem..."

"What happened?"

"Someone accessed the Chamber over the last two days since I have been here and created traps for me. I managed to dispel the few I found so far, but the intruder burned down the entire library, including the two recent tomes. Right now, it's no longer safe down here..."

Aurelius' book grew in size and twisted over the page: "That is our punishment for being so naive and shortsighted. Our actions have consequences, Harry, especially those of a time traveler. The timeline has already been changed permanently, so we must finally oust this dangerous and false sense of security. You must stop acting so omnipotent and all-knowing."

"You are right." Harry sighed and exhaled deeply: "I believed myself invincible but just because Voldemort did not act a certain way last time, doesn't mean he won't change his approach this time around. However, I really did not see him sending his Diary to Hogwarts. Why would he do that?"

"I have an idea... You challenged him as Slytherin's heir when you encountered him during the destruction of the Ring Horcrux." Aurelius mused: "I believe his very pride might be hurt and he considered reminding the wizarding world that he is the one true descendant of the Founder. What better way to prove that than to return to the castle and set Slytherin's Monster free?"

"Perhaps..." Harry nodded: "But there has to be more to it than simply unleashing the Basilisk and killing muggle-borns. Dumbledore and I once theorized that the Diary is a weapon and a defense at the same time. He is essentially cloning himself and able to spread his influence within Hogwarts without physically being there. This could very well be an attempt to simply recruit more students for his cause and radicalize them."

"He could also be trying to find out about the whereabouts of his other Horcrux. That certainly seems like a task he would trust no one else with, hence he does it himself." The tome added.

"There is too much going on right now, we need a solid plan of action." Harry jumped up from the chair and strode back and forth in the Chamber: "The ultimate goal is of course to find out which student is being possessed and to get our hands on the Diary. Someone from Slytherin sounds the most obvious, but I certainly won't limit myself to that. It could be any student, willing or unwilling. However, before we isolate the student, we need to limit Riddle's influence and sway within the castle."

"I agree." The burst nodded: "There are precautions you can take to secure rooms like the Chamber and the Room of Requirements. They will make it difficult for Riddle to access them. However, unfortunately, you won't be able to restrict the Horcrux's communication back to its creator."

Harry groaned and scuffled his hair: "Of course... Last time the Diary thought Voldemort had been bested. However, this time around, it will immediately contact Voldemort to let him know that the Chamber has been found by someone else."

He grumbled and slummed back down into the chair. His head felt like it was about to explode. There was too much information and too much to do: "That means I need to protect my identity at all costs. Voldemort can't learn that I'm the Parselmouth, not with so many people being close to me right now."

"Let's summarize the Diary's potential goals then," Aurelius suggested: "It accessed the Chamber, so chances are it intended to release the Basilisk on the students once more. With the serpent dead and knowing what we do about Riddle's pride, his priority will be to find the second Parselmouth now."

"And potentially secure the other Horcrux." Harry added while he fumbled through the bag for some parchment and a quill: "Although, the Diary could have only received that piece of information from Voldemort himself, since the man hid the Diadem many years after the Diary's creation."

He scribbled down the few key points on some parchment and bid his bottom lip: "Even though the Chamber is close to useless, I still want to find a way to keep Riddle out of it and if it's just to annoy him."

The tome chuckled: "From everything you have told me he would certainly count it as a personal insult to be banished from a place he must have spent years looking for. And I think I know just how to do it and apply the same method to the Room of Requirements." The tome added in an amusing voice.

Harry looked up from the parchment with a frown: "You want to use your creation? The Fidelius? Within Hogwarts?"

"Not an easy feat, but it would make for an interesting challenge." Aurelius' burst nodded: "The Room of Requirements, or should I say Hidden Things, will be exceptionally difficult to hide due to its size. However, hiding the Chamber should be relatively easy..."

"How so?" Harry felt confused: "I understand the difficulties with Rowena's room since the magic embedded in it wants it to be found and used by the students of the castle. However, the Chamber is also powered by ancient magic and incredibly large."

"But you don't have to twist reality and hide the actual Chamber from the world, Harry, do you?" Aurelius corrected him.

Harry's face lit up like a light bulb: "I only have to hide the one room it's possible to access the Chamber from: Myrtle's Bathroom, which is way smaller!"

"Exactly." Aurelius nodded proudly: "And I suggest you do it as soon as possible."

"I know the spell." Harry whispered and flicked the Elder Wand into his palm: "You have taught me all about it and I should be strong enough for it."

"It's one of the most complex pieces of magic ever created by humans, if I may say so myself." The tome chuckled once more: "However, I am confident that you can pull it off by now."

"Let's see then, shall we." Harry nodded and flipped the tome close.

With his wand held at the ready, Harry exited the main Chamber while continuously casting detection spells at his surroundings. He found nothing so far, but he would sweep the entire Chamber again once its entrance had been secured against Riddle.

Over the last few months, it had become a habit to check Myrtle's bathroom and the surrounding corridor on the Marauders Map each time Harry went back up. With this Cold War going on against Riddle, it seemed more important than ever to make sure his presence down there would go unnoticed.

He unfolded the Map and his green eyes narrowed when they spotted a name hiding behind an alcove a few meters further down the corridor leading to the bathroom.

'Serena Maul'

If Harry was not mistaken, she was a seventh-year Hufflepuff Prefect, a student he had never paid much attention to. It seemed fairly unlikely that she was actually the student possessed by Riddle, yet her appearance close to the bathroom was hardly a coincidence. 'A scout or a messenger then.'

The Elder Wand slipped into his palm and performed a slow twirl over Harry's head. His limbs and torso took on the color and texture of the cold stone walls behind him, as Harry climbed up the last few stairs leading into the bathroom. Of course, he could simply avoid Riddle's scout now that he was invisible, but instead, Harry could also use this opportunity to learn more about his enemy.

A silencing charm on the sink made sure it did not make a single sound when Harry ordered it to open from the inside. Luckily, Myrtle seemed to be somewhere else at the moment. He consulted the map one last time, making sure that the Hufflepuff girl had remained in her position and the rest of the corridor was empty. Then Harry checked his disillusionment charm in the mirrors and took a final deep breath. 'Time for some action.'

He pushed down the handle of the door and fired the spell a split second later:

"Confundo!"

A brown-haired girl, who peeked behind the corner of the alcove was hit straight in the face. Harry watched as her dull, empty eyes gained a slightly dreamy expression. Just as he had expected. 'She was under the influence of the Imperius.'

Harry used the few seconds it took the girl to regain her composure to wave his wand in a wide horizontal arc. The air shimmered ever so slightly as his illusion manifested itself. The girl would continue seeing a snapshot of the empty corridor and abandoned bathroom while a small magical barrier blocked her from witnessing what happened right behind it.

Harry took a few deep calming breaths and readied himself for casting the most complicated piece of magic he ever attempted. Hours of listening to Aurelius Peverell and detailed instructions on how the charm worked swirled through his mind.

Channeling his magic, Harry felt small waves of power surging through the Elder Wand as he pointed it at the door to the bathroom.

"Secretum Absconditum In Anima!"

A bright white beam erupted from the tip of his wand, bathing his side of the corridor in a blinding light. Harry continued pushing his intent through the wand, aiming right at the door handle.

Aurelius' words echoed through his head: 'You have to truly mean it, Harry. To bend reality itself, your desire to keep the secret secure must overpower anyone else's wish to find it.'

His vision blurred as he felt the spell taxing on his core, taking every single ounce of power available. When it felt almost too painful to continue, he drew the Elder Wand back and pointed it above his left chest, with the tip touching the material of his robes, right above his heart. 'A secret in a soul.'

"Fidelius."

Heat rushed from his chest through his arm. He felt it pour through the length of the Elder Wand, almost burning the tips of his finger as it passed them. A pulsing, hot wave of magic burst from the tip of his wand and effortlessly penetrated his robes and skin, nestling itself somewhere close to his heart. Harry sucked in a deep breath, surprised by the almost painful sensation, and felt his knees giving up underneath him.

Panting heavily, Harry looked up just in time to see the door to the bathroom faint from view, simply merging with the rough stone. A second later it reappeared, looking just as he remembered and as if nothing happened to it.

'It had worked.'

'He was the Secret Keeper!'

Harry was utterly exhausted, magically, mentally, and physically. He felt the taxing effect of the spell on his entire body, from head to toe. Nevertheless, the rush of ecstasy from successfully casting one of the most advanced charms on earth lifted his spirits. 'Now it was time to deal with Riddle's scout.'

Feeling too drained to recast his disillusionment charm, Harry threw the Invisibility Cloak over his shoulders and stepped through his own illusion back into the main corridor. The thin barrier of magic felt like passing a cold waterfall but did not stop its creator from passing through it.

The Hufflepuff prefect was still hiding in her alcove, watching the illusion in front of Myrtle's bathroom. Harry carefully sneaked all the way over to her side. 'The Confundo had been timed perfectly.' He watched as the dreamy expression subsided and the empty, yet focused stare, with which she regarded the door to the bathroom, returned. With her left hand, she pressed a small sheet of parchment against the wall, her right hand held a quill.

'A messenger then.' Harry frowned.

There was no need to know the direct instructions of the Imperius to gather that she was sent up here to watch the entrance to the Chamber and write down the name of whoever vacated it. Closing his eyes, he traced the Elder Wand over her piece of parchment and found a Protean charm, similar to what Hermione had used for the DA galleons. Whatever was written on this note would be shown on a second, possibly third piece of parchment.

'Not bad, Riddle...'

Harry could help but be impressed. If it was not for his Map, he doubted whether he'd been able to stop the girl quickly enough from scribbling 'Peverell' or even 'Harry' on the paper. That information would have undoubtedly been sent to Voldemort the same night.

He slowly brought his wand to the girl's temple, doubting that it would reveal anything. Tom would not make such simple mistakes... 'Yet it was always worth a try'

"Legilimens!"

He connected their thoughts and delved into the girl's mind, looking for anything that might give him a clue as to who placed her under the Imperius. Harry patiently followed her train of thought to her most recent memory.

"Are you sure you don't wish to visit Madam Pomfrey?"

An empty corridor stretched ahead of him. Harry recognized the fifth floor, close to the northeast tower. A boy stood next to him, sporting the same black uniform with yellow highlights as Serena Maul's.

"I'm perfectly fine." The boy replied in a drawn-out monotone voice, there was no sparkle in his eyes, they almost looked lifeless like the orbs of an Inferi.

"Let's go back to the fourth floor then." Serena suggested: "There is nothing up here."

She turned around on the spot to head back in the opposite direction when her vision was suddenly consumed by darkness, the last thing Harry heard was the word 'Imperio'

Harry cursed as he interrupted the connection and departed the girl's mind. 'This was a waste of time.' Riddle was using a chain of Imperius curses and tracking them all the way back to their origin could literally take days.

'Obliviate!'

Harry thrilled his intent through the Elder Wand and erased the girl's memories of their encounter. His skill in the mind arts was far from perfect, but Riddle would have to watch hours of her memories to find the missing thirty seconds during which Harry had invaded her mind. Even then Riddle would find no leads that might trace back to Harry.

The girl's eyes regained their empty expression and she continued staring at the entrance to the bathroom, unknown to what had happened around her.

Harry's fingers twitched towards the note in her hand, his mind spinning with amusing ideas on how to irritate Riddle by writing him a message on the parchment. A younger Harry would have fallen victim to the temptation, but not him. 'This was too important.'

Just as with Professor Bletchley there was no reason to give away his advantage. Why should he give Riddle any reason to doubt that his strategy of placing a messenger on the door had failed? Voldemort's Horcrux would simply come up with even more promising methods to identify the Parselmouth inside the school.

Harry chuckled as he withdrew from the girl and headed in the opposite direction: 'Best of luck to you, Tom.'

Unfortunately, this approach also meant that he would have to leave the Serena Maul under Riddle's Imperius for now. Harry swallowed down the small stab of guilt at meddling with the affairs and potentially lives of another student. He cursed Dumbledore's name, realizing that sometimes the Greater Good did come first.

The sooner he brought an end to this Cold War and captured Riddle, the fewer students like Serena would find themselves robbed of their own free will. Unfortunately, the Hufflepuff would have to suffer the consequences for a few more hours.

His nemesis might have gotten the initial strike, but now Harry held the advantage. Mere minutes ago, any and all knowledge on Myrtle's bathroom was erased from anything with a consciousness that could store it. Be it ghosts, portraits, house elves, full or even partial souls.

'The Chamber of Secrets used to be Tom's sacred kingdom.

Now it belonged to Harry until the day he died.'

10 Minutes Prior, Headmaster Office

A sharp golden beak snapped upwards, catching the spinning sherbet lemon in mid-air.

"That was my one, Fawkes." Dumbledore chuckled after closing his mouth: "And I even managed to line it up perfectly."

The Phoenix thrilled a soft tune and threw his golden head back, swallowing the sweet candy in one big gulp.

"You will get sick again and make me carry you to Poppy if you continue eating that many sweets." Dumbledore belittled his familiar and turned his attention back to the letter he was reading.

The sound of one of his instruments spinning far quicker than usual made him look up in curiosity: "Now what could that be?"

Suddenly another half a dozen instruments started spinning, emitting large puffs of smoke or even screeched like the wildest banshee.

"Albus!" Armando Dippet, his predecessor's portrait shouted from the wall while covering both his ears with his hands. He was not alone. Nearly every single former headmaster or headmistress of Hogwarts hid behind the edge of their frame. The lucky few who had different portraits vacated their frame altogether.

Fawkes seemed to be very irritated by the high screeching as well. With a few flaps of his wings, he sailed over to his porch and hid his head underneath golden feathers.

"I admit, I am slightly out of my depths." Albus twirled his long silver beard and tapped one instrument after the other with the tip of his wand.

"My many devices caught the casting of a magnificent piece of magic within the walls of the castle, unlike anything they have been calibrated for." Albus hummed, more curious than annoyed by the shrill sounds: "Simultaneously, this instrument... "He pointed to a complicated-looking small display made of metal: "... just informed me that there has been at least one change within the actual wards of the school. They have somehow been manipulated without my permission."

"Impossible!" Phineas Nigellus Black spied into the office, ready to depart back to Grimmauld Place should the volume rise again: "Only the headmaster has full control of the wards. No student or teacher could manipulate them."

"I am just as surprised as you are, my friend." Albus chuckled.

"There is nothing funny about this matter, Albus." Armando frowned down from his frame: "What if a student got hurt or some of Hogwarts' protections have been disabled?"

"None of that has happened since these two instruments..." He pointed to the back of his large desk: "... had remained quiet. The magic that was cast was not of dark nature, simply powerful." He cast a few more spells on the other device: "In addition, I can confirm that all the protections are still in place."

"Then what in Merlin's name happened?" Basil Fronsac inquired.

"I can assure you that I will do my very best to find out." Albus smiled, excited about finally encountering a challenge again.

September 11th, 1976

"Have you heard? Someone or something killed all of the gamekeeper's roosters."

Harry's head instantly snapped up from his breakfast and turned towards Florence: "How did you find out? When did it happen?"

The girl was taken back by the firmness in his voice and seemed almost frightened by his outburst.

"I overheard two of the ghosts talking about it yesterday." The brunette gulped: "Apparently the Fat Friar learned it from the gamekeeper himself. They have no idea what exactly happened, but they assume it was some animal from the Forbidden Forest."

"Are you okay, Harry?" Marlene squeezed his hand and shot him a worried glance.

"Yes, it's fine," Harry replied dismissively. He was processing the information at a rapid speed, but unfortunately, it did not give him any new leads. Aurelius and he had already assumed that Riddle intended on opening the Chamber to unleash the Basilisk on the students. Just as he had in Harry's second year, Riddle did not risk exposing Slytherin's monster to any risks.

Harry continued to consume obscure amounts of breakfast. Casting the Fidelius had left him quite weak last night and he still felt some of the after-effects. Nevertheless, the work was done, or at least, the first part of it. There was a slight problem that Aurelius and he had encountered last night...

Flashback:

"So tomorrow night, once I am fully recovered, we will repeat the very same thing just with the Room of Requirements?"

"I am afraid it won't be that easy, Harry." The burst flickered: "There is another problem..."

Harry groaned: "Not again... What is it this time?"

"The Fidelius was designed to allow a single wizard to store a single secret in a single soul." The tome explained patiently: "I could not even begin to imagine the consequences of burdening your soul by forcing another secret upon it. The human soul is unrivaled in its complexity, and we are likely to never fully comprehend it. However, everything I can think of points in the same direction. If you try to reshape reality once more and hide a second secret of such magnitude in your soul, the physical, mental, and magical strain could seriously harm you, Harry. Permanently."

"So I need a different Secret Keeper?" Harry sighed.

"Yes, you do... And I think we both know the best possible candidate."

Flashback End:

That was how Harry and Marlene found themselves on the seventh floor in front of the Room of Requirements that night.

"So why is this necessary again?" Marlene raised an eyebrow at her boyfriend, who walked back and forward across the blank piece of wall with his eyes closed.

After his third turn, a large door appeared and she watched as Harry tentatively opened it to peek inside. Standing on her tiptoes Marlene spotted a massive room that harbored the accumulated junk of generations of students. Harry kept the door open and turned around, facing her.

His wand flicked once and Marlene felt a slight tingle as a silently conjured privacy ward was raised around them: "I have reason to believe that another one of Voldemort's Horcruxes has been smuggled into the castle by a student. How I know this is a story for a different time." He held up a hand to signal his understanding: "I hate keeping these secrets from you as much as you dislike being kept in the dark. However, now is not the time, Marlene, please just trust me."

"Fine!" She sighed, her mind spinning with the different possibilities, however, only one made the most sense to her: "You mentioned that these Horcruxes can be sentient, didn't you?"

Harry nodded.

"So you think it might try to find this room to retrieve the other soul fragment?"

"I don't know if it wants to retrieve it or just check on it to report back to Voldemort." Harry took a deep breath: "The important thing is that it may never find this room."

"And how do you plan on hiding the entrance to the room if Voldemort already knows where it is?" Marlene challenged.

"I am going to hide it by using the Fidelius Charm." Harry simply stated as he trailed his wand over the entrance in a wide arc.

Marlene's thoughts were racing. Everything that she had figured out about the Room was thrown together with what she had learned about the Fidelius charm: "You want me to be the Secret Keeper? Why?"

Harry frowned: "Because I already preserve a different secret and I don't want to risk burdening my soul with a second one. The consequences would be very unpleasant. You were my first choice since you already know where the room is and you are the only person I would trust with this."

Her heart squirmed at the sincerity with which he spoke those words, yet her mind was not fully convinced: "I'll do it, but it won't work, Harry." She shook her head.

An amusing grin appeared on his face: "And why is that, Ms. McKinnon?"

"The Fidelius can only hide a fixed location and the larger the area you try to hide the more difficult it gets." She gestured to the door of the Room of Requirements: "The room might be located on the second floor, but we both experienced how it's able to manipulate space and let you exit at different floors anywhere in the castle."

She took a step closer and gave him a small sad smile: "You are undoubtedly one of the most powerful wizards of our age, Harry, but I doubt that even Merlin could place the entirety of Hogwarts under the Fidelius."

her boyfriend merely smirked at her: "Once again you prove to be the perhaps smartest witch of your generation, however, you overlooked one aspect." He motioned for the entrance to the Room: "I am not trying to hide the entire Room of Requirements, only the Room of Hidden Things, which could be characterized as a derivative of the Room."

"The Room of Hidden Things is clearly defined, at least spatially, and won't suddenly jump from one floor to another. It will only appear on the seventh floor and you can only exit it back to the seventh floor, nowhere else in the castle." Harry explained.

"So you don't want to stop the Horcrux from accessing the Room of Requirements, but only the Room of Hidden Things?" Marlene nodded her understanding.

"Exactly." Harry grinned at her and seemed to be preparing himself, by taking a few deep breaths: "Are you ready?"

"I think so." She nodded and positioned herself in front of him, watching the door to the Room.

The long, thin tip of her boyfriend's wand started glowing faintly: "Secretum Absconditum In Anima!"

Marlene forced her eyes to remain open, despite the blinding bright light. Harry pointed the tip at her blouse, right above her left breast. The magic was pulsing from it in strong ripples, making the hairs stand on her entire body:

"Fidelius."

Nothing could have prepared her for the magical shockwave that followed. Heat spread through her entire body and was compressed into what felt like a tiny orb, floating somewhere deep within her, presumably next to her heart. She involuntarily sucked in a deep breath. The feeling was not uncomfortable, just very foreign to her. In front of her, Harry dropped to his knees, panting heavily. He seemed to be in pain.

"Harry!" Marlene bent over and steadied him as best she could, helping him back up. 'Why did he have to be so heavy?': "Are you okay?"

"I'm fine." He cleared his throat and glimpsed towards the wall: "Did it work? I can't see the entrance anymore, but you should be able to."

Marlene turned her head and peeked through the open door into the room, just as he had been able to a few minutes ago: "Nothing changed for me."

"Share the secret with me please." Harry grimaced in pain: "I need to know if it worked properly."

"The Room of Hidden Things is located on the seventh floor at Hogwarts Castle, opposite the tapestry of Barnabas the Barmy," Marlene gave him as precise directions as possible.

His face lit up mere seconds later into a triumphant smile: "We did it! I can see it again."

"That was unlike anything I have ever felt before." Marlene chuckled and helped him over to the wall so he could rest against it: "I wouldn't be surprised if half the castle felt that shockwave."

Harry's eyes darted up and he stared at her in shock: "We're on the seventh floor..."

"Dumbledore's office," Marlene whispered after gulping heavily when the realization hit her.

Suddenly the couple heard a pair of footsteps approaching from right behind them, echoing through the abandoned corridor, accompanied by a whistled tune...