Hermione's lateness was unavoidable, but just as Moody's anger surged, he caught sight of Tver following behind her and immediately swallowed his fury.
As a Death Eater utterly loyal to Voldemort, Barty Jr. wasn't exactly afraid of Tver, but he had no desire to provoke another direct confrontation with him.
"Five points from Gryffindor!"
"Huh?"
"What, you want detention as well? Let me tell you, my detentions aren't nearly as gentle as certain other professors'!" Moody roared at the class, his meaning unmistakable.
Hermione, who had been closest to him, shrank her neck instinctively and hurried back to her seat.
"Professor Fawley, go ahead and find yourself a seat. Oh—looks like there aren't any empty ones." Moody cast a deliberately slow glance around the classroom.
"That's a bit awkward. We can't very well ask the students to give up their seats for you, can we?" He ignored the students frantically signaling that they didn't mind at all. "So perhaps Professor Fawley can stand for a while…"
Tver paid no attention to the sarcasm. He simply walked to the edge of the classroom and sat down on thin air.
Under the students' astonished gazes, an exquisitely crafted cushioned stool slowly rose up from the floor, neatly supporting him.
"What is it?" Tver asked calmly.
"N-nothing."
"Then let's begin the lesson. We've already wasted enough time, and the students have been looking forward to it."
Moody cleared his throat and took several deep breaths, forcing himself to calm down.
No need to lower himself to that level…
"I was told by Dumbledore that you've learned quite a few methods for dealing with magical creatures, and that you've also picked up some counter-curse techniques from Professor Fawley."
The students immediately burst into proud laughter.
According to complaints passed down by upper-year students, over the past seven years the only professors who could truly be called reliable were Professor Fawley and Professor Lupin.
And those two, especially Professor Fawley, just happened to be the Defence Against the Dark Arts professors who had taught these fourth-year students all along.
"However—"
Moody deliberately dragged out the word, drawing everyone's attention.
"—I've noticed that when it comes to dealing with certain… exceptionally powerful forms of magic, you still lack a great deal of experience and proper responses."
"Exceptionally powerful?" Hermione asked uneasily.
"That's right!" Moody said excitedly as he strode toward the front of the room.
"Originally, I planned to teach you ordinary spells, following Professor Fawley's rather… conventional approach."
He flashed a self-satisfied grin, which looked particularly vicious on his scarred face.
"But I believe you should try exposing yourselves to something a bit more… dark."
"Especially dark magic that cannot be freely used in the wizarding world!"
"Then… shouldn't we be learning to avoid it instead?" Hermione's unease turned into fear, her voice trembling.
Clearly, she already understood what kind of magic Moody was talking about.
"I'd wager that your beloved Professor Fawley, back when he was your age, could already toy with dark magic as if it were nothing more than ants."
"And just as a reminder, students at Durmstrang study dark magic under the supervision and guidance of many professors."
Teachers counted as professors, Tver pointed out silently. That logic checked out just fine.
"So," Moody said smugly as he opened a drawer and pulled out three glass bottles containing snarling spiders, "this lesson will be taught by me."
"Rather than waiting until some ill-intentioned wizard tries to harm you before you ever get a chance to see such magic."
No one argued. He decisively opened one of the bottles and pulled out the spider inside.
"Now then, in the wizarding world, which spells will earn the harshest legal punishment if used on a person?"
Ron gripped his wand tightly, resisting the urge to cast "Arania Exumai" at the spider. It was the spell he had practiced the most.
"I remember one… uh, my dad told me about it."
"And what would that be?"
"It's… it's the Imperius Curse, I think. I don't remember exactly—"
"Correct!" Moody raised his wand and pointed it at the spider in his hand.
"Imperio!"
The spider shot out a strand of white silk and dangled from Moody's hand, swinging back and forth like it was on a playground swing.
But its movements were stiff and unnatural, as if countless invisible threads were controlling it, forcing it into an awkward, jerky tap dance.
Tver watched the scene with a faintly amused expression.
Seen from this angle, Barty Jr.'s mastery of the Imperius Curse was nothing particularly impressive.
If he were the one casting it, the spider would move with complete naturalness, dancing as if it were acting of its own free will.
That was what a truly advanced Imperius Curse looked like.
The controlled creature retained its original will, except that it obeyed every command given by the caster.
"Funny, is it?" Moody barked at the snickering students. "What if you were the ones being controlled? What if I ordered this spider to leap straight down your throats?!"
"That's the Imperius Curse. It turns an innocent life into a puppet in your hands. You can resist it with sheer willpower, but that takes an exceptionally strong sense of self."
"Back then, plenty of wizards claimed they were under the Imperius Curse. As for whether that was true or not… that's something only their own hearts know."
He guided the spider back into its glass jar and took out the second one.
"Anyone else know another? The illegal kind."
Under the stunned gazes of the class, Neville hesitated, then finally raised his hand with determination.
"Go on, lad," Moody said.
"The Cruciatus Curse…" Neville said softly.
Moody's expression sharpened, both eyes fixed intently on Neville.
"Longbottom?"
Neville gave a small nod.
"Engorgio. So you can all see it clearly," Moody said knowingly as he raised the spider. "Crucio!"
The spider immediately curled in on itself, convulsing violently.
It made no sound at all, yet it terrified the students more than the most horrifying scream imaginable.
"Stop!" Hermione screamed.
Everyone followed her gaze and saw Neville gripping the desk in front of him so tightly that his knuckles had turned white. His eyes were wide, his breathing ragged and uneven.
"The Cruciatus Curse. One of the cruelest forms of torture there is. This spell makes it feel as though pain is radiating from every inch of your body."
"And that pain… can be lethal."
Only then did Moody lower his wand. He placed the spider back into its jar and took out the third one.
"But there is another spell," he said, "one that can destroy life with ease."
He placed the restless spider on the desk in front of Hermione.
"Miss Granger, tell us its name."
"Avada Kedavra…" Hermione murmured, stealing a glance at the expressionless Tver before lowering her head.
A sense of dread suddenly washed over Harry. His eyes flew open as he watched Moody raise his wand.
"Avada Kedavra!"
A flash of green light Harry would never forget shot out, striking the unfortunate spider with unerring precision.
There was no twitching, no convulsions. The spider flipped over and lay completely still.
It was dead.
Harry realized that instantly.
"The Killing Curse," Moody muttered, almost to himself. "The most feared spell in the wizarding world. A terrifying magic that even the Shield Charm cannot block."
"All right, what are you all standing around for? Write this down!"
"These three spells are nearly impossible to defend against, which is why they're collectively known as the three Unforgivable Curses."
"If anyone is found to have used any of them, the Ministry of Magic won't hesitate to throw you straight into Azkaban!"
The students shuddered and hurriedly bent over their notebooks, scribbling furiously.
Or perhaps the lesson had already been carved deep into their memories.