Defense Against the Dark Arts Needs Theorems / Snape Is Researching Wolfsbane Potion

Also this afternoon, Lupin is going to teach the second-year students their first Defense Against the Dark Arts Class. He went to the doorman's hut last night to see Harry and ask if Harry would like to attend class with him.

Harry readily agreed, even thumping his chest, only to discover the next day at noon that Lupin's class clashed with Severus Snape's.

"Um... just to confirm, are you sure it's okay for you to skip Snape's class like this?"

On the way to the Black Magic Defense classroom, Lupin asked with a worried expression.

"He's already done it, do you think he'll calm down if I go back now?" Harry sighed helplessly. "Whatever, at most he'll just yell at me or ask me to do some chores, he's not going to poison my medicine."

I'm afraid he'll poison my medicine... Lupin sighed helplessly to himself.

He had come back this time because he needed Snape's help, and he had originally planned to try to curry favor with him.

Now, things have gotten really messy. Before the first full moon even arrived, Harry has already caused a rift between them.

However, at this moment, Lupin did indeed feel that Harry's way of learning was a bit too unbelievable.

Despite being only a third-grader, he can work as a teaching assistant and earn a salary. He can teach classes at school whenever he wants, regardless of grade or time, and skipping classes or even leaving school is completely his freedom. He can probably even register for OWL exams at will...

With this level of freedom, even a Britain prince probably couldn't be as arrogant as him.

Believe it or not, Lupin was right.

He had actually met the Britain prince this morning, but the prince behaved in a very proper manner, so Lupin or the other classmates did not guess his identity.

Incidentally, Harry was also quite satisfied with Will's performance over the past day and a half.

He doesn't need to show off his intelligence too much. As long as he maintains his current low profile and keeps a basic good relationship with his classmates, he can have a normal campus life without too many ups and downs.

"Speaking of which, why did you insist on having me accompany you to the first class?" Harry asked, puzzled, as the two chatted on the way.

"I heard you taught the second graders," Lupin explained with a smile, "So I thought the first lesson would go more smoothly with you watching over them. Besides, I'm also curious to see what your students are really capable of!"

"So that's your reason for bringing this thing out?"

Harry casually picked up the water tank he had been holding in his arms; it was a 'teaching aid' that Lupin had borrowed from the Black Lake specifically for his lessons.

The box was covered with a black cloth, preventing anyone from seeing what was inside, but Harry knew perfectly well that a small creature was crouching inside, trembling.

This was supposed to be material for third graders, but Lupin brought it out early. He really thinks highly of those students!

But... what's with this inexplicable sense of pride?

"Speaking of which, I've found that your name really works," Lupin patted the water tank in Harry's hand. "I just shouted it out by the Black Lake, and they readily lent it to me."

"Of course." Harry straightened his back proudly. "Generally speaking, Uncle Lupin, just mentioning my name means you can practically walk around Hogwarts Castle with your head held high!"

When facing elders with whom he has a close relationship, Harry can deliberately act a little 'arrogant' to make him appear more childlike and prevent his loved ones from perceiving him as an unapproachable monster.

"Yeah, I know, after all, he's the Hogwarts God of War." Lupin nodded in agreement, but then added with a smile, "Except when he's facing Snape, right?"

"Uh... you're absolutely right."

The thought of Severus Snape's face, which looked like he'd just eaten a dead rat, made Harry's heart pound uncontrollably.

To put it bluntly, in typical cases, Severus Snape are extremely petty and narrow-minded.

I skipped his class this time, who knows what he'll do to me later...

After turning another corner, the two finally arrived at the corridor where the Defense Against the Dark Arts classroom was located, but they encountered Peeves wandering around there.

"Haha, isn't this Lupin? The stupid and muddle-headed Lupin?"

Upon seeing Lupin, Peeves immediately started making a loud, unruly noise.

"Peeves," Harry glared at the prankster, "Lupin is my uncle."

"Is... is that so? Oh, Peeves is wrong! Lupin is actually Lord Granger's uncle, so he's not that stupid and muddle-headed fool! Ahahaha, Lupin is really amazing~"

Peeves took off his hat in front of Lupin, shook it, and then ran away laughing.

"Uh... your name really works! It even managed to keep Peeves in check." Having witnessed this scene firsthand, Lupin was at a loss for words.

Simply mentioning Harry's name grants him unrestricted access to the Hogwarts campus, and even the Merpeople of the Black Lake treat him with utmost respect... Well, Lupin can barely accept all of this.

But the fact that Harry could manage to subdue Peeves so easily is a bit too much.

You know, even those four Marauders had to be careful and watchful of the Peeves when they were fooling around back then.

"It's alright, anyway, like you said, except when facing Severus Snape."

At the mention of Snape, Harry sighed again and followed Lupin into the classroom.

"It's Harry!"

"Harry came with Professor Lupin!"

As expected, the second-year students, who had been somewhat sullen, burst into excited shouts when they saw Harry enter the classroom with Lupin.

"Alright, alright, everyone quiet down, second-year students." Lupin smiled and nodded to the class. "Before we begin, I want to clarify something: you don't need to be so excited about Harry's arrival, because I can assure you... he'll definitely be coming quite often in the future!"

"Very good!"

"Long live!"

Seeing the jubilant atmosphere in the classroom, Lupin nodded in satisfaction.

He was a very intelligent man. From the applause at the opening ceremony, Lupin sensed a clear sense of crisis, knowing that the second-year students at Hogwarts didn't actually respect him as much as Harry.

Therefore, in order to quickly build rapport with the students, he needed Harry to stay by his side and help him with his first lesson.

Moreover, Harry is absolutely an impeccable teaching assistant; he demonstrated his support abilities to the fullest in yesterday's Care of Magical Creatures Class.

In Lupin's opinion, since Harry could even carry Hagrid, a bronze-level character, carrying him would be an easy and enjoyable task.

(P. S. Hogwarts Street, ask around...)

Chapter 294 Defense Against the Dark Arts Requires Theorems

"Now we'll begin class. Please put away your textbooks, only keeping your wands. Today's lesson will focus on practical application."

After the self-introductions, Lupin waved the water tank from Harry's hand and placed it steadily on the lectern.

After that, he ripped off the black cloth covering the water tank.

"This is what you're dealing with today!"

"Squeak~"

Caught off guard and exposed to everyone, the little creature in the water tank immediately let out a series of screams.

It used its long claws to cut the surrounding seaweed to shreds, leaving an unpleasant scraping sound on the tank glass, which made many young wizards frown.

It's clear that although this guy isn't very big, he's quite fierce.

"Can anyone tell me what kind of creature this is?" Lupin asked the class.

"Grindylow is Fantastic Beasts raised by the Merpeople of the Black Lake," Luna Lovegood answered with just a glance.

"Very good, Miss Lovegood." Lupin nodded approvingly. "Now, who else can tell us about the dangers and weaknesses of this creature?"

An awkward silence fell.

Lupin's question went unanswered this time, and after whispering among themselves for a while, many of the young wizards looked troubled.

Second graders don't have much experience with Fantastic Beasts, let alone those that live in water. Luna Lovegood was the only one in the class who knew about them, but she clearly didn't want to answer any more questions.

"Does nobody know? This is troublesome..." Lupin scratched his head awkwardly, looking at Harry with some difficulty.

He had assumed that Harry's 'ability set' would allow him to introduce a lot of knowledge about Fantastic Beasts to the second-year students in advance, which was why he prepared this Grindylow, which was supposed to be used in the third-year classes, to test the overall level of the young wizards.

Unexpectedly, the students had no idea about this at all.

"It's alright, it's worth a try." Harry, however, wasn't worried at all and smiled as he gestured to Lupin to do as he pleased.

Lupin wanted to see the abilities of the second-year students, Harry naturally agreed wholeheartedly, and was absolutely certain that these kids would definitely surprise him.

"Alright, since Harry thinks it's feasible, I'll test everyone's learning level beforehand." Seeing that Harry had no objections, Lupin readily agreed. "I'll release this Grindylow from the tank, and your task is to find a way to force it back in..."

A commotion erupted, and before Lupin could finish speaking, all the students in the classroom rose from their seats and rushed to the open space at the back of the classroom, forming a line and raising their wands in a state of readiness.

"What are you doing..." Lupin's expression froze upon seeing this, and he looked at Harry with a conflicted expression once again.

"It's alright, Professor Lupin, you can continue." Harry gave a harmless smile.

"Heh." Lupin chuckled dryly, vaguely sensing that Harry's smile was definitely not hiding anything good.

However, he still followed the original plan and retreated to the side of the podium with Harry.

"Alright, let's begin the test!"

With a snap of his fingers, Lupin flicked his wand, and the lid on top of the tank vanished instantly. The already extremely agitated Grindylow leaped out from a clump of seaweed.

However, what Lupin then witnessed left him speechless.

"Waddiwasi!!" *N

With a chorus of incantations, dozens of marbles rained down on Grindylow on the podium in a mere instant!

"Squeak! Squeak~ Squeak!"

Caught off guard, Grindylow was hit directly by more than a dozen marbles and quickly scurried back into the water tank. However, the students still showed no sign of stopping, and in the next volley, the water tank on the podium was also smashed into a pile of glass shards.

"Stop... stop it! You all need to stop!" Lupin was shocked to see this and hurriedly stepped forward to stop them. "This Grindylow is borrowed from the Black Lake, and I have to return it! You all need to stop..."

Finally, thanks to Lupin's relentless efforts, his neck stretched out, the students' attack came to an end.

However, the podium was now a complete mess, and Grindylow had hidden under it... When Lupin found it, the little guy actually buried its head in Lupin's armpit and refused to come out again!

"Harry... why did you teach them this in their first year?" Lupin asked, his eyes filled with resentment as he cradled the pitiful Grindylow.

They actually taught first graders how to use the Waddiwasi Spell, and it was even a volley version!

What, are you trying to develop a three-stage spear formation?!

"These are the basic principles Harry taught us when dealing with unknown Dark Magic." Before Harry could speak, Ginny stepped forward, her tone full of admiration. "When facing an enemy or magic whose situation is unknown, the first principle is to keep your distance, never get close, and prioritize using ranged Waddiwasi Spell Charm for probing attacks."

"If the Waddiwasi Spell is effective, we can change the spell accordingly and launch the next offensive," Colin followed Ginny, adding, "If the opponent can withstand the Waddiwasi Spell's probing attack, we should immediately cast the Shield Charm on ourselves as a precaution; but if the Waddiwasi Spell is ineffective, or even ignored by the opponent..."

"Run." Luna Lovegood gave her final answer succinctly.

Lupin:...

In that instant, so many thoughts rushed into his mind that Lupin didn't know where to begin.

Damn... how did you come up with such a brutal 'basic principle'?

And judging from what these students are saying, they've already mastered the Shield Charm?

This is a spell that can only be learned by upperclassmen, and even many graduated wizards cannot master it!

How exactly did he teach his old friend's children, a group of second graders?

And... why do I feel like I'm being outdone?

Realizing that he had actually lost to a third-grade student in terms of professionalism in the Black Defense course, Lupin's mood suddenly turned subtly sour.

He realized that Dumbledore might have appointed him as the Defense Against the Dark Arts professor simply because he didn't want Harry to be distracted by a substitute teacher, thus affecting his studies in other subjects...

Okay, so it turns out I'm the teaching assistant~

"The so-called fundamental principles are actually like the Gamp's Law of Elemental Transfiguration; they're a kind of theorem." After cleaning the podium with a Scouring Charm, Harry explained earnestly to Lupin, "As for the various ways to deal with different Dark Magic situations, those should be considered specific solutions."

"The scope of Dark Magic is all-encompassing, and wizards cannot possibly master every single solution. However, the underlying principles remain the same. If one can use theorems as a guiding ideology, one can eventually integrate and understand these complex solutions."

Chapter 295 Snape is researching the Wolfsbane Potion.

Harry would have a hard time explaining the theorem to these wizards who hadn't even finished middle school math.

But to put it simply, the theorem of Defense Against the Dark Arts is actually one of offense and one of defense.

If you can repel the enemy and protect yourself, then you've already passed the test in Defense Against the Dark Arts.

As for the subsequent ones, such as 'use garlic to deal with vampires' and 'avoid being scratched or bitten when dealing with Werewolf ', these are all specific offensive and defensive measures derived from the theorem, and they are not applicable in all situations.

Does that mean you can't fight vampires without garlic on hand?