Being at Hogwarts, something's not right with this system.

After dinner, Lin Yu still took some time to go to the door of the principal's office, which was also located on the eighth floor.

It seemed that Dumbledore was also waiting for him, so the door was open.

Lin Yu knocked on the door again before going in: "Headmaster Dumbledore? Are you there?"

Stepping into the round office again, Lin Yu couldn't help but look around.

There are many books here, and the walls are covered with portraits of past principals.

Lin Yu couldn't help but sigh, "Sooner or later, I'll hang there too, and be revered by people."

"A very good idea, very ambitious, but I like it very much, because I also hope to hang here after I die," Dumbledore looked up from the back of the office, smiling, and praised Lin Yu's ambition.

It turns out he had been there all along.

When Dumbledore looked at Lin Yu, the portraits of the headmasters hanging on the wall behind him also turned to look at this young boy who dared to speak so arrogantly.

Some portraits are silently nodding, while others are holding their heads high.

They seemed to be scrutinizing Lin Yu as well.

"Come here, child," Dumbledore said, remaining seated and beckoning Lin Yu over.

Lin Yu strolled over and noticed that next to the desk, on a shelf, Phoenix Fox was looking at him curiously.

Lin Yu curiously reached out and cautiously touched Fox's head, gently smoothing the phoenix's feathers.

Dumbledore simply smiled and watched, waiting for Lin Yu to withdraw his hand before saying, "She likes you very much. Fawkes has the bloodline of a mythical beast in your China, a sign of good fortune. Since she approves of you, I believe you're not a bad boy."

Lin Yu raised an eyebrow, inwardly asking the system, "Am I considered to have completed my mission?"

System: "Task completed, reward has been sent to system space, you can check it at any time."

Lin Yu was very happy to have another thousand low-grade spirit stones.

He then looked up and asked, "You didn't just call me here to praise me, did you?"

Dumbledore sighed, pointed to the mountain of letters on the table, and stated his purpose: "Although you are a good boy, you have caused me a lot of trouble. The matter of the Marrow Cleansing Pill can no longer be kept secret."

Lin Yu found it strange because yesterday, Saturday morning, he had already seen piles of letters delivered to Dumbledore's desk.

So why are you only coming to find me now?

Dumbledore seemed to sense his curiosity and explained, "Yesterday, only some acquaintances wrote to me asking about the veracity of this matter. But now, people want to ask more about the Marrow Cleansing Pill. Even the Ministry of Magic wants to specifically ask you about it, as well as the question of whether the Marrow Cleansing Pill can be mass-produced. Also, I heard from Snape this afternoon that he's been spending the last two days in the library, but he doesn't know anything about alchemy. Can you tell me about that?"

Lin Yu's lips twitched, and he subconsciously said, "Is it possible that Professor Snape went to the wrong library? Should he try checking our national library if he gets the chance?"

are you crazy?

Looking for information about Chinese alchemy in the library of Hogwarts Castle in the English Highlands?

Snape, do you want to hear if what you're doing is even worthwhile?

What, did the Eight-Nation Alliance put all the loot they stole in Hogwarts?

"That's what I advised Snape too," Dumbledore shrugged, looking nonchalant. "But what I'd like to say is, next time, could you let me see how you concoct pills?"

So this was Dumbledore's real purpose.

Lin Yu blinked, then suddenly asked the system in his mind, "Is there a mission?"

He wouldn't mind demonstrating it to Dumbledore in person, but it would cost extra.

System: ...Wanla, he figured you out?

The host has developed a brain?

Ultimately, the system still said: "Grandmaster Zhang Sanfeng... Dumbledore will teach you 'Tai Chi Fist' and 'Tai Chi Swordplay.' Learn these two moves diligently. Mission complete. Reward: True Tai Chi Fist and True Tai Chi Swordplay, plus an additional 5,000 low-grade spirit stones."

Lin Yu was taken aback. Tai Chi Chuan and Tai Chi Sword?

It also emphasized "truth"?

It seems you also know that Dumbledore doesn't know Tai Chi or Tai Chi sword at all.

On the other hand, I've already cultivated immortality, and I even have the Cloud Abyss Nine Styles, a sword technique for cultivating immortality. Why would I care about Tai Chi Chuan or Tai Chi Sword?

But five thousand low-grade spirit stones? I can't refuse that.

So Lin Yu made a decision in his heart, looked up at Dumbledore and said, "Since you want to see it, then of course I have to fulfill your wish. But as you know, this kind of thing is very secretive. If I remember correctly, Harry's grandfather quadrupled his family's fortune with a shampoo formula. And you should have heard that I set the price of the Marrow Cleansing Pill at one thousand Galleons."

The meaning couldn't be clearer.

You want to see it? Sure, but you'll have to pay extra.

This is a case of using one pill for two purposes.

Dumbledore looked at the cunning little lion and almost laughed out of anger. He did laugh, and asked with a smile, "I'm not going to give you a thousand Galleons. But you can try to suggest something else."

Lin Yu certainly wasn't after money, so he readily agreed, "How about you teach me a couple of spells? They don't need to be too powerful, or even offensive."

Dumbledore then realized that Lin Yu had this idea all along.

However, considering the commotion caused by the Marrow Cleansing Pill, even Minister of Magic Cornelius Fudge came to inquire about it.

Dumbledore felt he had to see it for himself.

Dumbledore then agreed, saying, "I can agree to that, provided you can satisfy me."

In other words, Lin Yu shouldn't think he can easily fool this old man.

Lin Yu readily agreed.

So Lin Yu began to make preparations. Dumbledore even had Fawkes bring a note, and before long, he summoned Snape.

"Professor Snape," Lin Yu said, glancing at Snape before taking the initiative to greet him.

Although their meetings ended unpleasantly, Lin Yu still felt that Snape was not a bad person at heart.

Of course, Snape didn't give him the slightest bit of a friendly look.

Lin Yu shrugged, too lazy to keep trying to win him over, and turned back to fiddling with his things.

He took out the large alchemy furnace again, but this time he took it out of his Qiankun Ring, instead of having the system serve him.

After that, Lin Yu continued to take out medicinal herbs from his Qiankun Ring.

Snape's heart skipped a beat. He reached out and took a portion, then looked up blankly after a moment and asked, "What's this?"

"That is...."

Lin Yu casually mentioned the name of a herb that didn't exist in this world.

Not only had Snape never heard of it, but even the well-informed Dumbledore had never heard of it either.

Only then did they vaguely realize that the Marrow Cleansing Pill seemed to be truly difficult to replicate.

Even if they know the formula, what if they don't have the ingredients?

Even a skilled cook can't cook without rice.