Chapter 19

"This place is magnificent," Gellert said, running his finger lightly across the blood-stained blade of a cursed axe. "Albus, I take my hat off to you. Hogwarts well deserves its reputation."

"Few know of this room's existence," Albus said, "but Hogwarts has indeed earned its reputation."

Gellert looked around, still enthralled.

The size of this enormous place impressed him less than its contents.

From the looks of things, there should have been Hogwarts students expelled for far worse than he had committed in Durmstrang. Objects imbued with some of the darkest magic he'd seen were strewn around like sweets after a child's party.

There was no rhyme or reason to this place.

Failed experiments lay alongside ordinary schoolboy contraband. A cursed glittering ruby emanating malice sat beside a harmless pornographic magazine on a graffitied table.

The size alone would have made searching it difficult, but the nature of half of its contents amplified the difficulty greatly. It was complete chaos.

Gellert was in love again.

"Don't get distracted," Albus warned him, pointlessly. "We are here for a purpose, as you well know."

"Yes yes," Gellert said, hefting a blunt axe that was calling to him. "Purpose, yes, of course. Destroy a Horcrux and bring back anything that seems useful."

Albus eyed the axe.

"And that will be useful?"

"Probably not, but I want to hang it above your fireplace. You can feel it's curse, surely?"

"It shouldn't require any force to cleave a man in two. Why do I need it in my cottage?"

"It's a conversation piece, and no home is complete without a mounted blade."

Albus rolled his eyes and walked off through the heaps, eyes peeled in every direction.

Gellert eyed the axe once more before putting it down. It wasn't even goblin-forged, and he could enchant one far better.

But this place—intoxicating. All well and good for Albus to go on about keeping the eyes on the prize, but Gellert spotted a collection of Peruvian shrunken heads with actual Quechuan carvings in them.

Into the sack they went, along with some enchanted sapphires and an entire pickled human spine.

He spied something draped over a broken chair.

"How—" he mumbled, darting for it, his wand out and scanning.

"How could it—what—who on Earth—"

Lost for words, he lapsed into silence, running his hands over an empty Dementor's cloak.

Most definitely one for the sack.

He could hear house elves and ghosts calling to one another, Albus' strident voice ringing instructions and warnings above all others, but they did not disturb his private search.

He delved deeper into the room, looking around for the Horcrux as he passed, but his eyes were still darting around for more treasures.

There were plenty to be found.

It did not take long for Gellert to realize that he could happily spend years in this place and never run out of items to collect. He needed to return to the main search, but it was all so enticing…

I'll come back here, he promised himself. When Voldemort is dust, I will return and rescue more of these prizes.

His breath caught and he hurried forward, all but knocking over a house-elf in his haste.

There, stacked atop a pile of charred books, was a series of small plaques.

They looked like dominoes at first glance; at least, to one who did not know what such things were and could not feel their thrumming power.

By all the gods, how could they be here? Even in Durmstrang, even in the ancient lands, such were impossibly rare, the art of crafting them having been long lost in the haze of time and war.

The knowledge of using them could still be found, albeit with great difficulty, as Gellert could attest, but to actually craft them—

These, he could tell just by being so near, had been crafted perfectly. They must have been ancient, possibly dating back to near the founding of Hogwarts.

The bottommost one was a burned ruin, but the others—

Gellert's knees went weak as he reverently took the Runes, fondling them one by one, and placed them gently into the stack.

They would come in handy, and soon.

He let his senses drift wild as he walked, eyes focused on everything and nothing, feeling the cursed and half-formed things in the room sing to him.

Occasionally, he would pick something up to examine it. An athame and a glittering golden flower dropped into the sack, but nothing else piqued his interest.

A research project for decades, he thought, just to catalogue the contents.

He would make it happen, one day. The room would bustle even more than it currently was, and he was certain there were already more beings in there than ever before in its prodigious history.

Ghosts and house-elves floated and scurried, respectively, around the place by the hundreds; Albus was walking through the room, along with his tame death eater, Nymphadora, Black, and of course, Gellert himself, while above them all, Fawkes swept the air, searching from the sky.

If the Horcrux was indeed here, it was surprising they hadn't found it yet.

Gellert reached the end of the corridor and turned, coming face to face with the ghostly monk he'd spoken with previously.

"We meet again," the ghost said with a smile.

"So we do," Gellert said. "I'd have thought you'd make like the rest of your compatriots and avoid me."

"Then you clearly don't remember our conversation too well. I am not frightened of death, or even the pure agonizing nothingness of exorcism, no more now than the day I died."

The ghost glided closer to Gellert.

"Have you thought of our conversation? Are you still so content to view yourself a monster?"

"As I told you then," Gellert said, "I am what I am."

He waved a hand, forestalling the next question.

"But I know I am no monster. I had cause, recently, to see a true monster, as I was in my heyday, and I am no longer that man. What I am, I still do not know for certain, but I am no monster any longer, of that I am sure."

"That is all well and good," the monk replied," but shouldn't you spend some time to find out what you are?"

Gellert was spared the need to respond by a sudden shout which went out—a high-pitched whoop of glee.

Hurrying back toward the source of the commotion, it became readily apparent that the Diadem had been found. Albus was sending the house-elves and ghosts away, clearing away rubbish and treasure from a pile of crates.

And there it was. Tarnished and dimmed, not the headdress befitting the renowned Rowena Ravenclaw, but the Diadem of fame regardless.

It simply sat there, hidden in plain sight, inches away from a plaster head, no doubt made to look as if it had fallen from it.

Perhaps it even had.

Now it just sat, looking perfectly innocuous, undeserving of the fear and wary glances the few present were giving it.

This close, Gellert could feel the enchantments on the were the complete opposite of those on the Ring. While the Ring had called to any in sight, had enticed and compelled them to put it on, the Diadem had subtle charms which enhanced its shabby appearance to disguise its malevolence, prevented the eye from settling on it for too long, and made it simply meld into the background.

Brilliant. Were it not for Albus' constant reminders about what exactly they were searching for, and the presence of house-elves who saw more clearly than humans, they could easily have missed it.

"And here we are," Albus said softly. "Any traps that you can sense?"

"No," Gellert said. "This was simply not meant to be found at all."

"Indeed. Would you like to do the honours, my friend? Especially after all your babbling about blades?"

Albus had drawn the Sword of Godric Gryffindor from somewhere.

Gellert hefted it, grinning.

Then without warning he swung, Black and Nymphadora jumping back to join Snape a few feet away, and sliced through the Diadem as if it was nothing.

The Horcrux screamed as it died. A high-pitched wail echoed from the Diadem as tarry smoke dripped from its cut.

Then, as suddenly as it had come, it was over.

"Will someone explain what the bloody fuck that was?" Nymphadora shouted.

"Later," Black said, "you can ask Albus."

"That was great fun," Gellert said. "I would very much like the pleasure of the next."

"We shall see," Albus said. Then he pulled out his pocket watch and glanced at it.

"Hmmm. I promised Harry if I had the time I would meet with him and his friends, and it seems I do, in fact, have the time. Gellert, how would you feel about perhaps…describing how they should fight, maybe showing them a few tricks? Nymphadora, Sirius, you are both welcome to join, of course."

Gellert's grin grew fit to split his face.


Harry sat eagerly between Ron and Hermione, eyeing Dumbledore and and Grindewald as they walked into the Room of Requirement.

They'd been chatting merrily with Sirius and Tonks—Sirius more than Tonks, to be honest—for a while, waiting for the titans to appear.

Sirius and Tonks had both changed, though Tonks' differences were so much harsher that comparing her to Sirius was a sad joke.

Sirius was simply more, well, serious. He joked less, spent less time chatting with them than he had when they'd stayed at Grimmauld Place, and when he was at Hogwarts he was a slave driver when it came to duelling and the like.

He hadn't held back much, either. At first, he'd faced them three on one, and though he used no lethal spells, of course, they were all left bruised and bleeding at the end of every bout.

Still, day by day they'd been improving, especially since they continued training after Sirius would leave for the day.

Now, Sirius duelled them one on one, and even though he still won nine out of every ten fights, Harry, Ron, and Hermione were leaving them far less injured than in the past.

Sirius still joked a bit, but it was always with a guarded look, his hand never far from his wand, steel always in his eyes.

Tonks, on the other hand, seemed almost an entirely different woman to the one who had arrived at the Dursley's house to break Harry out.

She barely spoke, only making one comment to Harry that "this orphan shit sucks, right."

She'd joined Sirius for their training the day before the Hogsmeade attack, and even then Harry had noticed the changes in her.

They were only more pronounced since then.

It wasn't only her speech and sense of humour which seemed to have left her. She wasn't using her Metamorph abilities the way she had been previously.

Today, her hair was as black as his own, with a line of red through it, but every other time he'd seen her it had been a depressing brown. Also, though he'd never say it, especially where Hermione could hear, she looked far blander—she'd obviously been using her abilities to spice up her looks a bit in the past.

More than all that, she had a feeling about her, like a spring wound up and ready to burst. Her clumsiness was no longer evident; if anything, she seemed to ghost her way around objects as if they weren't there.

Beyond all that, there was just something about her, some aura that told Harry that she was dangerous, that if she was on the other side, she would be scary as hell.

Her presence had dulled the atmosphere somewhat, but they'd still been chatting animatedly with Sirius—who seemed more serious than ever, even while joking—while waiting for Dumbledore and Grindewald.

And now they had arrived, cutting off all conversation with their entry.

The Room was the same as the one they'd used for their DA meetings, and Grindelwald looked around with an expression as of he was unsure whether he was impressed or disappointed.

It was Harry's first real look at the man in person. He was shorter than Dumbledore and wore no beard, and the tufts of hair on his head were dazzlingly white. A scrawny man, at first glance he looked as if he would fall over in the wind, but then Harry really looked at his face.

Wrinkled as it was, strength was carved into it, strength and sheer brazenness. His eyes were alight like none Harry had ever seen before, seeming to glow from the inside. His crooked grin was as much a smile as a warning, and he took in everyone and everything in the room in an instant, clearly assessing and dismissing them as threats.

Dumbledore just smiled and opened his arms wide.

"Ah, perhaps Hogwarts' greatest secret," Dumbledore said. "The Room of Requirement. A great boon to our magnificent school."

"Very much so," Grindewald said. His voice surprised Harry—it was accented, but not as heavily as he would have expected, and more so, it was young and powerful.

"Indeed. Gellert, I think Sirius and Nymphadora need no introductions, but this is Harry—"

Grindelwald's eyes fixed on Harry for a moment, his face inscrutable.

"—Miss Hermione Granger, and Mr Ronald Weasley."

"Charmed," Grindelwald said with a wave of his hand.

"And this gentleman, as I'm sure you're all aware, is Gellert Grindelwald."

"Scourge of Europe," Grindelwald said, "Terror of the Wizarding World, MACUSA's most wanted, and more."

"I've invited Gellert to join us," Dumbledore said, "since I believe he will be of great assistance in helping you all to learn how to fight dark wizards. Unfortunately, matters outside of Hogwarts demand our attention, and so our time is limited, else I would say we could join Sirius on his daily forays, but alas, we cannot."

"We're more than grateful for anything," Harry said, after sharing a very excited look with Ron. "Really."

"I'm glad. I think it's best that the time we have is not spent teaching spells or the like, but learning the general methods you should be making use of. And with that, I will hand it over to you," Dumbledore said, gesturing to Grindelwald.

Grindelwald, grinning widely, paced before them, stroking his chin.

"Where to begin—Tell me, any of you, what is Dark Magic?"

"Magic made or used to hurt people," Ron said quickly.

That wasn't quite it, Harry knew. He thought of Voldemort rising from the cauldron, of the terrible feeling of being possessed, of seeing Tom Riddle's memory gloating in the Chamber of Secrets.

There was much more to Dark Magic than just hurting people.

Grindelwald shook his head.

"No. You, Granger—no need to raise your hand, girl, this isn't a regular lesson, what do you think Dark Magic is?"

Blushing, Hermione lowered her hand, but spoke in a voice as clear as she did in classes.

"The corruption of magic through intent and will, for example, twisting healing magic to cause pain."

Grindelwald's eyebrows rose along with the corners of his lips.

"That's a quote," he said, pointing a finger at her, "from Strangheim's introduction. You didn't happen to see the first or second editions, did you?"

Dumbledore was hiding a smile. Ron and Harry, meanwhile, both looked shell shocked. It was the first time in years Hermione had answered a question with a quote and received anything more positive than exasperated points for Gryffindor.

"No," Hermione said animatedly, "the restricted section only had the fifth edition, and it's the same as the one the Room brought me."

"A shame," Grindelwald said. "his work is still very instructive, but the uncensored early editions much more so. Regardless, you touch on the heart of the matter. Dark Magic, in its purest form, is about corrupting that which is good."

The adults looked engrossed, Tonks most of all.

Grindelwald continued to pace, his face wistful.

"You will not face much of this, I do not believe. A true master of the Dark Arts, one who uses them as they are intended, unchained and undefined, is a rare find—Voldemort is one, to be sure, but among his acolytes I would be surprised if there were more than one or perhaps two. Still, you should understand at least the theory. Corruption. Darkness where there should be light. The twisting of all that should be good and pure into obscene mockery."

Harry was mesmerised, unable to look away from Grindelwald's striding form.

"None of you can understand what it truly is, as you are simply too young, too inexperienced and untutored. The limits of magic are well beyond what you can be taught in school; the greatest books can only be a stepping stone. Magic is nigh unlimited, a force that cannot be measured or weighed, a force that can only be understood through deep usage of it at it's truest level. Ah," Grindelwald spun, pointing at the trio.

"You have been taught all sorts of theory, heaps of formulae and the requirements to make magic do as you bid, for your spells to be cast as you wish. These are all important, but they are not eternally important. They are not the sum of a magical education—"

"And, I hope, you all understand that this does not mean you can skip classes as you wish," Dumbledore added with a twinkle in his eyes.

"Yes yes, all that. All this is but the foundation, something you must come to know intimately—"

Fucking hell Harry thought savagely, though Hermione looked smug as anything.

"—but true mastery of magic comes when you progress beyond the chains, reaching an inherent understanding of its nature. Most do not reach this, but it is possible to stretch beyond simple pre-crafted spells and wand movements, to come to a place where all that matters is the magic itself, your intent and will, and your power."

"This does not only apply to Dark Magic," Dumbledore added. "Think of any of the spells you have learned. Someone went before you and spent quite a while researching how to harness that raw power into one which can be used by all in the same manner. But, as Gellert will explain, it is quite different with the Dark Arts."

"Yes, Albus," Grindewald said, peeved, "I haven't fallen into a rambling lecture yet. Be sure to remind me if I do."

Fawkes squawked something.

"Oh, shut up, you."

Harry could barely keep from laughing and Sirius wasn't even trying.

It was hard to believe that this man had literally murdered millions.

"Sidetracks aside," Grindelwald said, facing them once more, "think of a child performing accidental magic. He does not incant, does not use a specific motion or even a wand. He does not even think a spell. He thinks that he wants something to happen, and it does."

"But accidental magic—" Ron started, then cut himself off.

"No need to stop, boy. Carry on."

"Well," Ron said, his ears reddening, "accidental magic stops after a while, right. And it's a bad sign if it doesn't, isn't it?"

"Completely correct!" Grindelwald exclaimed, clapping his hands. "Accidental magic stops because as the child grows he learns more about himself and the world, and his instinctive reactions change to meet the world's expectations. Few wizards," here he looked at Dumbledore for a second, "are ever capable of regaining that instinctive response. But that is raw magic at its finest and most dangerous, and that is part of why magic and nature ensure that accidental magic stops. Magic must be constrained for the majority of wizards, else they will have no control over what they do in a moment of anger."

Harry thought of glass vanishing, of a giant snake escaping through a crowd of people and couldn't help but grin.

"And so we formalise magic. Researchers come up with the incantations and wand movements necessary to perform certain spells, and they become common usage. This is where the Dark Arts differ."

Grindelwald's smile looked a tad unhinged now. Harry leaned forward, barely noticing how, for the first time that day, Tonks seemed truly alive.

"As a rule, the Dark Arts are not formalised the way the magic you are familiar with is. Their very nature denies it. The act of corruption is personal, and will be different for every single wizard. There are, of course, exceptions."

He nodded pointedly at Harry.

"Like the Unforgivable Curses," Harry said.

"Yes. By the way, how does it feel to know that you are not only the only recorded survivor of the Killing Curse, but also the only person to have experienced all three and lived to tell the tale?"

Harry shared a dumbstruck look with Ron and Hermione, honestly having no idea how to respond to that.

"I know," Grindelwald said to Dumbledore, "tangent. The point is, part of why the Unforgivable Curses are so dangerous is that they have been formalised. They will work for any wizard of sufficient power with the right intent. For much of the Dark Arts, that is not the case. Tell me, what is the incantation for a Hovering Charm?"

An image of a club dropping on a troll's head flittered into Harry's head, as he was sure it did for Ron and Hermione.

"Wingardium Leviosa," they said in unison.

"Very good. How many other incantations for a Hovering Charm are there? Let's keep it located to Britain, shall we?"

Harry and Ron looked at Hermione, who was chewing her lip, deep in thought.

"Three," Dumbledore said, after several minutes of silence. "but none that have been in widespread use in the last century or so."

"Albus, this is a lesson for the children."

Dumbledore mimed zipping his mouth shut.

"Let us say there are no other incantations for it, which is effectively the truth. How many incantations exist, again, only within Britain, for the creation of an Inferus?"

When silence greeted him, Grindelwald sighed.

"What the hell are you teaching them, Albus? Go ahead, you can guess."

"Five," Ron said.

"Seven," Hermione said, making Grindelwald's eyes slit for a moment.

"Twelve," said Harry. "At least. That's what you're getting at, right? Everyone comes up with their own?"

"The Boy Who Lived wins the day. To my knowledge, there are twelve recorded incantations in British times for the creation of an Inferus. Personally, I use none of those, but one of my own creation. Are you all beginning to see? The Dark Arts in general are about creativity as much as anything else. That which works for me, based on my intent and desire to make a mockery of life, will not necessarily work for others; if it does, it will not serve them as well. Do you understand now, why the Dark Arts are so feared? With no true formalisation of curses, there can be no true formalisation of counter-curses or cures, only generalities. You must learn these regardless, but they will never be as effective as personally crafted counter-curse."

"So you're saying it's hopeless," Harry said, his stomach sinking. "We can't face them."

"Don't put words in my mouth," Grindelwald said with a sneer. "There is always hope. And as I've already mentioned, the only ones who would be using the Dark Arts as they are intended are likely to be Voldemort or perhaps that Lestrange bitch and that Unspeakable, what did you say his name was?"

"Augustus Rookwood," Dumbledore said.

Tonks' hands, Harry noticed, had curled into fists at the mention of Bellatrix, her face twisting with rage.

"Even Voldemort, I understand, prefers to use the Killing Curse when not facing someone on his level. And that is why you must learn to do what you can."

"I've been doing what I can to reach them," Sirius said, "and they're far above the average kid their age's skill level, but—"

"But indeed," Grindelwald interrupted. "They won't be facing children their age, will they? It will be those tacky Death Eaters or Aurors, and so you must have every ounce of assistance you can. Your age will assist you, in fact, as they will underestimate you—perhaps not you, Potter, as you've survived Voldemort too many times, but the others—yes, your age will help."

Grindelwald began to pace again, silent for a few minutes.

"Apparition," he said suddenly. "I assume none of you are capable of it?"

"We're underage," Hermione said.

Grindelwald stared at her as if she was insane.

"And? Your point is that it's illegal? So what? All the more reason for you to learn it, another surprise the Death Eaters and Aurors will not expect. Or you can have it carved on your tombstone that you obeyed the stupid law. We are not playing gobstones here, girl, and there's no reason to treat it as such."

"I just—"

"You just meant that you hadn't been taught it yet, I know," Grindelwald said harshly, "but that's no excuse. You are fighting for your lives, whether you realise it or not. You cannot hide behind stupidity—"

"Enough, Gellert," Dumbledore said, gaiety gone from his face and replaced with severity. "You are here to instruct, not to berate."

"Well—fine. Learn to Apparate. Perhaps this Room can create somewhere within the boundaries of Hogwarts where Apparition is possible. Otherwise, Black, can you take them to the village and teach them? Are you able to teach Apparition?"

"I can teach it," Sirius said. "I learned to do it when I was barely older than them, and we had to help one of our—former friends learn. The question is if McGonagall will allow it."

"I'm sure that Acting Headmistress McGonagall will not present an issue," Dumbledore said, smiling slightly. "Sirius Black, are you honestly claiming you can't find a way to sneak them out of the school if necessary?"

Sirius's face brightened.

"Well, since Harry has his father's cloak and our old map, I don't think it will be too much of an issue. Let's see first if the Room will help, though. With all the new security on Hogwarts, I'd rather not risk it."

"For all we know," Harry said, "the Room might be able to make a tunnel to Hogsmeade or something."

As he said it, an unassuming door appeared on the wall behind the training dummies.

Silence fell, a feeling of seriousness taking the room.

"That," Dumbledore said, "will need to be a carefully guarded secret. We may need to set up a rotation of house-elves for warning, once we have explored where it leads. For now…"

The door vanished.

"We could explore it now," Harry said, "wouldn't that be—"

Dumbledore was shaking his head.

"Unfortunately, Gellert's and my time here is truly limited. We will return to do so, I assure you. If it is a risk, appropriate measures will be taken. That I promise you."

"Enough of that. Once you have learned Apparition, you must make use of it. Staying still in a fight will lead to your death. Running from and attempting to dodge curses are foolish, but doing so is better than nothing. Apparition is the way. Now then, silent casting. Your wand motions will still give it away somewhat, and to a brilliant enough enemy, your very intention will do so, but casting silently gains you a few instants. You will learn to do so."

"Bloody hard, though, we've been trying—"

"And you will continue to try," Grindelwald interrupted Ron, sneering again. " I may not be here to berate you, but I am not here to listen to complaints either. You will learn to do as I say or you will learn to lie still for eternity. You can choose which you prefer."

Harry shifted uncomfortably. None of the other adults, not even Dumbledore, were saying anything to contradict Grindelwald. It gave it all a rather surreal feeling.

"Occlumency. I assume none of you are masters, but you should assume that every enemy you face is a Legilemens, whether or not they are. A basic necessity to learning Occlumency is learning to control your emotions, and that is also a necessity on the battlefield. You must be ruthless yet calm, every motion calculated without fear or fury interfering. Learn to control your emotions, at the very least, and assume that if you make eye contact with an enemy he will know your planned next move and you will be dead."

"Not asking too much, is he?" Ron whispered, so softly Harry barely could hear.

"I am telling you to do what is necessary for your survival," Grindelwald said. "If that is not to your taste, feel free to leave."

"I—"

"Master the spells you know," Grindelwald continued, with nothing but a glare at Ron to show for the interruption, "be capable of casting them as quickly and repeatedly as you can. Learn the Killing Curse, and do not hesitate to use it against your enemies, for they will not show you similar mercy. Shields…you can teach them a Protego Horribilis?" He asked Sirius.

"I can try," Sirius said, "but that's a tough one to cast properly."

"Even improperly cast, it is better than the next best option," Grindelwald said, turning back to Harry, Ron, and Hermione. "There are shield charms galore, many of which would better suit you against the Dark Arts, but the one you are most likely to be able to cast is Protego Horribilis. Obviously, especially from someone with your level of experience, it will not stop the most powerful curses, but it will be a far greater asset than anything you are using now. Which brings me to my final point."

He paused for a moment, glancing around the room again.

"Make use of your environment. Too many wizards are trapped in their thinking that a duel is simply casting spells against one another. It is not. Everything around you is a weapon, you simply have to make use of it. Transfiguration is your friend."

Harry grimaced. Transfiguration was far from his forte.

"I doubt any of you can conjure, and that is a great shame, but you need to make use of your environment. For example—"

Gellert waved his wand, and a rock appeared. It floated gently toward Dumbledore.

"Imagine we were outside somewhere, and I sent, not a spell, but a rock from the street careening toward my enemy."

The rock moved slower them a feather. Dumbledore watched it approach, smiling, his wand nowhere to be seen.

"Of course, in a real fight, it would be more like this—"

A second rock appeared in mid-air and shot off toward the training dummies, striking one so hard that it's arm fell off to Hermione's gasp and Harry and Ron's muttered swears.

"Now, I'm sure you're thinking about how easy that is to defend against."

Harry hadn't been, and from the looks of it, no-one except Tonks and Dumbledore had been either.

"The simplest shield charm or deflection would prevent an impact. But while your enemy is engrossed in that, you do this—"

A series of spells shot from Grindelwald's wand faster than Harry's eyes could track, all of them Stunners by the looks.

"You bombard them, overwhelm them with everything. Turn the very street against them and behead them as they fight against what was rock but is now mud. Turn dust into knives and attack, but keep firing your spells."

The rock he had conjured was now halfway between Grindelwald and Dumbledore.

With a sudden slash of his wand, the rock shot forward, splitting as it did so into a dozen or so.

"Profe—"

Harry's shout caught in his throat as Dumbledore, still smiling faintly, reacted.

The rocks reached him and spun around him for a moment, before flying back at Grindewald, changing as they did so; in their place flew birds, dozens of tiny sparrow with metal beaks.

Not done, Dumbledore cracked his wand like a whip. Something flew from the end of it, an incredible force so powerful it was almost visible.

The birds had shattered a foot away from Grindelwald, turned into a collection of motley parts which still hung in the air, but Dumbledore's spell forced him to react. His wand spun, and a thunderous boom rocked the room with its impact.

Then they were clashing truly, Grindelwald's lips peeled back from his teeth, Dumbledore still smiling calmly.

What Harry witnessed was like nothing he had seen before. This, he knew, was what a true duel between the most powerful of wizards looked like, and he could barely comprehend what it would have been if they were fighting in truth.

The pieces of birds had been reconstructed by Grindelwald with barely a wave of his wand. Half of them became rodent-like creatures with terrible fangs, scurrying off toward Dumbledore, while the rest grew red hot and melted into liquid balls of fire, which flew at different times and speeds at the Professor. All the while, Grindelwald was sending off curses and hexes, occasionally with flashes of light but almost all invisible.

Dumbledore's reaction was no less intense. Everything, from fire to rodent, that reached an arm's breadth from him shuddered and dissipated, while he simply countered each spell with one of his own, occasionally cracking his wand again and forcing Grindelwald to conjure another shield.

Then he attacked.

Fawkes flew at Grindelwald with a horrific shriek that made Harry clutch at his ears while hundreds of ropes and chains appeared around Grindelwald, thrusting themselves at him.

Not enough for Dumbledore, he continued. A ball of darkness so black it seemed to suck in light appeared before him, and it careened toward Grindelwald faster than a bludger. When it was a foot away from Grindelwald it suddenly shook, and tentacles erupted from it, too many to count, all of them with sharp suckers lining them, all grappling for Grindelwald.

Finally, Dumbledore shouted an incantation that was entirely foreign to Harry, and the room lit up so bright that he was blinded.

Then it was over.

Blinking spots out of his eyes, Harry ignored Ron's cursing and tried to make sense of what had happened.

Fawkes was perched on Dumbledore's shoulders, as if he had never left.

Grindelwald, meanwhile, was apparently the loser. There was a rope hanging loosely around his waist, but devastation surrounded him. A small army of dead critters were everywhere by his feet, and cut tentacles littered the floor around him. He held one of them, stroking it gently, an eyebrow raised as he looked at Dumbledore.

"That was an unexpected gambit," he said, and if he was annoyed about losing, he didn't sound it. "You'd never have done that if this was not for show, yes?"

"Of course not," Dumbledore replied. "I know how you could have used it against me. Of course, if it wasn't for show, this would all have been a lot more serious, wouldn't it?"

"Certainly. And that, ladies and gentlemen," Grindelwald said, turning back to Harry and Ron and Hermione, his eyes lingering uncomfortably on Harry, "is our lesson for today. Learn the spells I advised you, and learn them well. Most importantly, be creative! They do not expect it, and surprise is your greatest weapon."

"We will," Harry said loudly, Ron and Hermione echoing his promise. "We will!"

"I'm sure the Death Eaters won't know what hit them," Grindelwald said with a nasty grin.

"Let us hope, rather," Dumbledore said, "that you are not placed in a position where you will need to face them."

Harry, however, knew that it was just a matter of time before Voldemort and his followers sought him out.

And he had no intentions of going meekly to his death.