Crucio

—The study.

It was the study, not the Chamber of Secrets.

This was something Snape had never heard of. From where he stood, however, he could see the shelves packed with books on the turning staircase. Cyberlina was telling the truth.

Cyberlina turned and entered the study. When she raised her wand, every torch inside lit up.

Harry followed Cyberlina into the study in a daze—he had been intimidated by the look Cyberlina had just given him.

Snape did not notice Harry's dazed state. He was only impatiently waiting for Harry to enter the study so he could leave the flagstone beneath his feet.

"CRUCIO"

Those were the words engraved on the flagstone.

An Unforgivable Curse he knew better than any other.

Combining the ancient traces remaining on the surrounding floor with that horrifying door, he had already figured out how people had passed through it before Cyberlina altered it.

Then, when Cyberlina entered back then, who had suffered the Cruciatus Curse?

Snape actually wanted to rule out Cyberlina, but when he remembered that Mr. Gaunt had come with her—the man Dumbledore claimed loved her so desperately that he obeyed her every word—he felt that perhaps Cyberlina had been the victim herself. But would Mr. Gaunt, who hated dark magic, use the Cruciatus Curse on her?

Snape gathered up his chaotic thoughts, slipped his wand into his sleeve, and entered Slytherin's study.

Directly opposite the entrance stood the old man's stone statue. The malicious lighting from below made it look sinister and terrifying. On either side of the statue were two winding staircases leading to the mezzanine lined with bookshelves.

Harry stood at the top of the stairs, staring incredulously at Cyberlina on the mezzanine. He exclaimed, "So... you invited me out for a night stroll... just to ask me to read?"

"It's about balancing work and rest. We just finished exercising, didn't we? Your mind is active, so this is the perfect time to read." Cyberlina held a book and teased him with a smile.

Snape glanced at them without a word, then walked up the other staircase with an expressionless face. After sweeping his eyes over the shelves, he spotted a spellbook that was supposedly lost to history and immediately became interested. Before taking it down, however, he looked at Cyberlina, who was speaking with Harry, and asked, "May I borrow books?"

Cyberlina turned around and waved the book in her hand at him. "You may not take them away, Professor."

"What about a Copying Charm?"

Cyberlina smiled. "You can try."

Snape understood. All the books here had been placed under a forbidden spell and could not be copied.

It seemed he could only transcribe them...

Snape took down the spellbook he had set his sights on and asked again, "How long may I stay here?"

"As long as you like, provided you don't get hungry. The house-elves can't bring food in here." As she spoke, Cyberlina looked at Harry. "You too, Harry. Tomorrow is Saturday, anyway. Neither of you has classes."

Harry nodded happily, no longer wearing the bitter expression from before—Cyberlina had just given him a book about broom-flying techniques.

"Unfortunately, your poor Potions professor still has to grade the assignments of the little trolls whose heads are full of Dittany." Snape remained expressionless, though the corner of his mouth curled coldly. "I wonder whether the great Mr. Potter might take pity on a busy old professor and prepare to hand in a blank assignment to lighten his workload?"

Harry froze, his delighted expression stiffening before slowly turning grim. He had forgotten that he still had homework to do—and not just for one subject. Whether out of dissatisfaction with Snape or pity for himself, Harry said instinctively, "I never had such a vicious thought as wanting to make things easier for you."

Snape's eyes widened. He immediately strode forward two steps, while Harry realized something was wrong and quickly hid behind Cyberlina.

"Oh... poor Harry." Cyberlina glanced at Harry with amusement, then at Snape. "Poor Severus."

"Sekerei!" Snape's sharp glare shot straight at Cyberlina.

Cyberlina raised her hands. "I'm your assistant, Professor. I'll help you grade the assignments!"

"You can't."

"I can. You know I can." Cyberlina kept smiling.

Snape stared gloomily at her, lips pursed as he said nothing.

Harry looked at Snape's expression and edged farther behind Cyberlina—Merlin! He knew Snape must be furious, but for some reason, the atmosphere made him want to laugh! Besides, he had the strange feeling that Snape dared to be angry but not say anything in front of Senior Sekerei... Yes, it had to be his imagination.

"All right, then." Cyberlina sighed. She walked to the bookshelf behind Snape, glanced at the spellbook in his hand, then smoothly took down an ancient Potions book and handed it to him. "Busy Professor, which will you choose: reading or grading assignments?"

"..." Snape held back for a long while before forcing out a word. "...Books."

Harry was now certain. Snape really did dare to be angry but not speak! Yet this absurd truth would have been better left unconfirmed!

Cyberlina cheerfully extended the book in her hand toward him. Snape accepted it with an ugly expression, then walked forward a few steps and lightly smacked Harry's messy hair—Stupid Potter! Don't think he hadn't seen him laughing secretly. After a cold snort, Snape went back down the stairs. He had noticed a table below where he could transcribe things.

Seeing through Snape's intentions, Cyberlina waved her wand. An oil lamp, a blank notebook, and two quills appeared on the table. Snape, who had been about to take out the parchment he carried, paused, withdrew his hand, and naturally sat down to open the blank notebook. Since his assistant had prepared it, he used it without the slightest guilt.

Harry, knowing he was in the wrong after being hit, grimaced but did not dare turn around as he opened the book in his hands. It was old but not worn: On the Techniques and Magical Applications of Broomstick Flight.

For a while, the only sounds in the study were the rustling of paper and the flames of the candles.

Cyberlina watched the two of them reading and gave a gentle smile. Then she lowered her head and opened the book she had held since entering the study—Slytherin's Book of Spells.

People tended to forget things as they aged. There were some matters she needed to confirm again.

To the two old Slytherins who were deeply versed in dark magic, Slytherin's study was a treasure vault. But to a second-year Gryffindor who still recoiled from dark wizards, it was very easy to be startled.

At first, Harry failed to notice that anything was wrong with the book in his hands. It was not until he saw—

[There is pressure in the air that obstructs the casting of spells. When necessary, one must reverse the broom or hang upside down from it in order to cast a spell and strike the opponent.]

Harry froze and began flipping back through the sections that had seemed strange to him.

["Tailfluffed" may be used on brooms to make their tails flare out and disrupt balance.]

[When pursuing someone, lure them to fly higher. The higher they go, the harder the broom is to control.]

Harry closed the book and picked several more books from the shelves, only to discover that every one of them concerned the study of dark magic. He fell silent. But then he remembered that this was Salazar Slytherin's study, and it suddenly seemed reasonable.

"Senior Sekerei." Harry walked up to Cyberlina with a very troubled expression. "I don't think the books here are suitable for me."

"Why?" Cyberlina had already closed the book in her hands when Harry approached. She had placed the letter she had drawn from it on top of the cover.

Cyberlina's composed attitude made Harry frown. He suddenly realized that Senior Sekerei had deliberately brought him into contact with these books on dark magic.

Why?

Because she was a Slytherin?

But that was no reason to let him study dark magic!

That was dark magic!

Could it be that Sekerei was already an evil dark wizard!?

The boy said nothing, but his expression told Cyberlina everything.

"What is Gilderoy Lockhart to you now, Professor?"

"Defence Against the Dark—" Harry answered instinctively, then stopped. He frowned at Cyberlina. "Defence Against the Dark Arts is supposed to teach us to resist dark magic, not learn it!"

"Then all that can be said is that the two professors you've had were both too incompetent." Cyberlina looked at him with a smile. "Do you think Headmaster Dumbledore is a good person?"

"Of course!" Harry felt that Cyberlina's words were full of hostility toward Dumbledore, and his tone immediately became heated. "He is the greatest White Wizard! Don't you dare slander him!"

Cyberlina raised her eyebrows in surprise at his defense of Dumbledore.

"I never intended to deny Dumbledore, Harry. I only wanted to say that he is very accomplished in dark magic."

Harry seemed to catch fire at those words. He abruptly stepped forward and glared angrily at Cyberlina. "That is slander! I knew it—Slytherins really aren't good people!"

Harry felt deceived, tricked by the good image Cyberlina had put on. This evil Slytherin wanted to make him fall into darkness.

He felt sad and angry.

He did not understand why Cyberlina was treating him this way.

"I am not slandering him. No one knows better than I do how good Albus is at dark magic." Cyberlina did not move at all, nor did she show any anger at Harry's words. She continued looking at him with a smile. "Parseltongue is considered evil. Does that make you evil, Harry?"

Harry hesitated, then abruptly turned his head away from Cyberlina's gaze.

"You aren't even sure what kind of person you are?" Cyberlina asked in surprise.

The almost taunting words made Harry grit his teeth, but he still chose silence. He turned angrily to leave, only to find Snape standing expressionlessly at the foot of the stairs, watching him.

It was a trap!

Harry's expression said it all.

Snape gave a cold laugh. "Great Mr. Potter, shake that empty head of yours and listen to the sound. What makes you think you have the ability to force two professors to go to such lengths to corner you here?"

Snape had never treated Cyberlina as a student, so he had unconsciously blurted out the word "Professor." In his feeling of having been "deceived," Harry failed to notice it. Instead, he sensed a deep threat from Snape. His mind rapidly began working backward, and his suspicions of Snape from first year resurfaced.

Could it be—they had been sent by Voldemort to lead him astray?

"Harry, do you remember what I told you? No matter what magic or skill it is, its use and the result after using it depend on the wielder."

Harry paused and turned back toward Cyberlina. He found that her pale golden-brown eyes were the same as when she had first said those words—gentle and kindly as they looked at him.

"I... I can't do anything about Parseltongue, but I won't learn dark magic!" Harry stared firmly at Cyberlina. "I absolutely won't become a dark wizard like Voldemort!"

Cyberlina looked puzzled. Several seconds later, she suddenly understood. "Harry! You have them confused!"

"...What?" Harry frowned in confusion. "What did I confuse?"

"You confused dark wizards with bad wizards." Cyberlina raised a hand and placed it on Harry's shoulder. "Voldemort is indeed a dark wizard, but in the context of what you just said, you should have said 'bad wizard.'"

"What's the difference?" Harry still frowned, but he was clearly calmer than before.

"A dark wizard is someone who studies and uses dark magic. Wizards who raise dark creatures count as well. Ministry of Magic Aurors need powerful magic to arrest wizards who commit evil deeds, and the Dementors in Azkaban require specialized Aurors to train them. They all count as dark wizards. So... do you think those Aurors who protect others and guard criminals are the same as Voldemort?"

Harry was stunned.

Snape frowned at Cyberlina. He had no idea what she was doing. Outside the study, he had been wondering whether Cyberlina, like Dumbledore, intended to cultivate Harry. But what did these words mean now? Was she trying to guide Harry into learning dark magic?

Snape's thoughts were tangled with conflict, but he did not make any move to stop her.

"Harry, tell me. What is dark magic?" Cyberlina's voice was gentle, her tone carrying a hint of guidance.

Harry opened his mouth, but could not produce an answer.

"I think dark spells are the leading category within dark magic. In The Standard Book of Spells, dark spells are divided into jinxes, hexes, and curses. I imagine you aren't unfamiliar with jinxes and hexes. After all, many of them are used by students for pranks—even quite a few Gryffindors use them. Are they 'dark wizards' according to your definition?"

Harry was speechless.

"The three Unforgivable Curses should fall under 'curses.' Oh, do you know what the three Unforgivable Curses are?" Without waiting for Harry to answer, Cyberlina continued on her own. "Crucio, the Imperius Curse, and—" She gently touched the scar on Harry's forehead. "The Killing Curse."

The chill on his forehead made Harry jerk backward.

"The magic I used to light the brazier when I entered could also count as a curse."

Harry: "!" He had really wanted to learn that one!

"The Copying Charm Severus mentioned while studying the ancient texts just now counts as one too."

Snape: "?" How had this involved him?

"Then, Mr. Potter, summarize this for me. What characteristic of dark magic can you learn from dark spells?"

Harry pondered for a moment, then lowered his head. "I don't know, Pro—Senior Sekerei."

"Irreversibility." Cyberlina looked at Harry seriously. "The consequences they cause cannot be reversed, and the objects they create cannot be destroyed. There is no denying that this is extremely dangerous."

"Then—"

"Don't rush, Harry."

Cyberlina moved her finger, and a book floated over from the shelf. She tapped it in midair, and the floating book opened automatically to a page facing Harry.

Harry looked at the book, then suddenly widened his eyes and took two more steps backward.

"Use it on me, Harry." Not a trace of a smile remained on Cyberlina's face. She was utterly solemn.

"No, no—" Fear appeared in Harry's eyes.

"Use it on me, Harry!" Cyberlina took two steps forward, her tone leaving no room for refusal.

Harry raised his wand, but still looked unwilling.

"Harry—" Cyberlina continued advancing.

Harry said nothing. He tightened his grip on the wand and stared without blinking into those golden-brown eyes devoid of laughter.

"Harry!"

Harry closed his eyes.

"Harry—Potter!"

"Crucio!" (Cruciatus Curse)

Harry squeezed his eyes shut, raised both arms, lowered his head, and shouted. Then he abruptly opened his eyes, his entire body turning cold as though his heart had stopped. What had he just done?

The surroundings fell completely silent. Harry stared fixedly at his toes, feeling the world spin and tremble. He could not tell where he was or even who he was. He only knew that he could not breathe. The trembling and chill rising from his tailbone left him almost unable to stand, much less think.

"Perfect spell, extraordinary magical talent—"

Cyberlina's praise, filled with laughter, came from above. Harry's legs went weak, and he uncontrollably dropped to his knees, his wand rolling away. Supporting himself with both arms, he instinctively gulped in air. Sweat and tears fell together, splashing onto the ancient stone floor and leaving dark wet marks.

"But completely useless."

Harry slowly raised his head. Through the blur, he saw Cyberlina's familiar smiling face.

"This is another characteristic of dark magic." Cyberlina considerately helped Harry up and straightened his glasses. "If you don't possess intense malice, you cannot use powerful dark magic."

Harry's mind was still foggy. He heard Cyberlina's words but could not understand them. He could only frown and stare at her with strained concentration.

Hurried footsteps climbed the stairs. Harry felt someone pry open his mouth, then pour in a liquid with an indescribable taste.

Watching Harry's eyes gradually clear after he drank the calming potion, Snape breathed a sigh of relief. Then he turned his fury toward Cyberlina.

"Have you gone mad! If you've had enough of living, Apparate to Azkaban yourself. There are plenty of beasts there who can use the Killing Curse! You don't need to waste your life at Hogwarts! I truly wonder whether you spent all those decades you were missing living in a troll den, letting its snot fill your brain!"

Harry, who had just regained consciousness, heard the long string of abuse. He instinctively looked up and saw Snape half-supporting him, his eyes cold and mocking as he glared furiously at Cyberlina.

"Forcing a twelve-year-old child to use an Unforgivable Curse—ha! What a powerful 'professor' you are, Professor Cyberlina Sekerei. That was the Cruciatus Curse! Not the Levitation Charm, not a game, and certainly not a tool for showing off your abilities! How dare you—how dare you teach it to a child who hasn't even learned basic spells! For Dumbledore to become the greatest White Wizard under your tutelage, he must have exhausted all the luck the British wizarding world had accumulated over thousands of years!"

Cyberlina blinked, staring at Snape in a daze. Then she mechanically raised her arms and applauded. "You really are gifted at insulting people, Severus."

Her tone was full of admiration.

Snape: "..."

Snape turned his head and discovered that Harry, who had recovered, was also looking at him with admiration.

"..."

Snape snatched Mr. Potter, the so-called savior, away from Cyberlina and shoved him aside, then waved his hand disdainfully.

These two—both of them were sick!