"Dobby, can you stay here and let's talk later?"

"No, Dobby must go back, back to his master ... Dobby sneaked out while his master visiting a friend." Dobby said emphatically, "A very close friend! So master won't let Dobby follow."

"Then come back, when you have time. No, I need time to prepare, you can let me know in advance." Felix waved and a brass-red, round piece of metal flew over from the workbench.

It is a brass coin.

He tossed the coin to Dobby, who reached out to catch it and looked at it carefully, "No, no, Dobby can't take it, Dobby doesn't deserve ANY money." He said in fear as if he was holding some evil black magic item.

Felix sighed, "That's for you to notify me. You inject your magic in advance, and I will receive the message."

This thing is a pair magic artefact, somewhat similar to the two-way mirror, but less functional than that.

It's just a pair of copper coins with 'synchronization enchantment' applied to them, and when you inject magic into one, the other one will become hot.

The 'Fever Coin' is a spin-off product of Felix's question-answering parchment, a product created through the collective brainstorming of those little wizards, with little technical content of its own.

Felix is also casually made it for fun, he also sent a pair to each of his research team in it.

The Weasley twins were interested in this, and Felix felt that it wouldn't be long before they would show him the remnants of the 'Fever Coin' ...

Hearing Felix's words, Dobby then relaxed, he carefully examined the coin in his hand, his eyes seemed to shine.

"Is this a gift for Dobby?" He asked, cocking his head and holding the copper coin in his hand.

"-You could say that." Felix had no intention of taking it back.

"Mr. Hap is so generous, it's the first time Dobby has ever received a gift!" The elf was moved to tears.

Felix: "..." I have a lot of similar trinkets if you're feeling happy...

As he watched, Dobby bowed towards him, then snapped his fingers lightly, then his figure disappeared.

"What an interesting talent," Felix said adoringly.

Creatures like house-elf were very magical, they had many 'wizard-like' abilities, for example, the technique Dobby just used when he disappeared is very similar to a wizard's Apparition, but the principles are completely different.

At least, as far as Felix knew, Hogwarts had a lot of anti-Apparition ward laid out, but this ward didn't work against some magical creatures - like phoenixes, or house elf.

On top of that, house-elf can manipulate all kinds of small things, which are very convenient for household chores and room cleaning; they also possess quite an offensive ability, although this ability has been firmly shackled by the magic contract.

But these are not spells familiar to wizards, rather they are the natural gifts of a magical creature who has these abilities, like a bird or snake magic creature that can enlarge and shrink its body at will depending on the space it is in.

...

When Felix returned to the great hall, the three professors were still carefully instructing the young wizard.

It had been two weeks since the last dueling class, and many of the older young wizards were barely able to cast the Disarming Charm.

This made the sparring between them have a bit of a shadow of a duel.

But it was only a shadow.

Felix then saw the two young wizards look at each other and chant the spell aloud, only to awkwardly shoot a shower of sparks from the tip of their wands. And then, without a second glance, unleashed a real disarming charm that came straight at him.

"Miss Bulstrode, be careful with your spell," Felix remarked to the stout-looking witch as he put off the spell. He looked at her twice more. If he was not mistaken, his own assistant had acquired cat hair from her and wore a knitted hat for three weeks for it.

"Oh sorry, Professor." Millicent Bulstrode said with some panic.

"You have to watch the angle of your wand and wield it hard as if you were stabbing it out. And ... faith is important, don't be playful, it will seriously slow down your progress."

After pointing out a few young wizards, Felix came near Professor McGonagall, where a small circle of people was gathered around her.

She was standing excitedly in front of a pair of young wizards, complimenting them loudly, "Potter, very excellent disarming charm." She rubbed the corners of her eyes.

As Felix looked over, a red light flew out of Harry's wand, hitting his opponent, Hermione Granger, precisely.

Her wand came out of her hand and arced in midair, caught in Harry's agile hand.

The little witch looked puffy.

Harry handed the wand somewhat smugly and was just about to say something when his next opponent had stepped forward.

Felix noticed, to his surprise, that opposite to Harry, there is a short queue, with a number of young wizards surrounding around, looking at Harry with adoring faces.

What is this situation?

When Hermione saw Felix, she quietly came over. "Professor Hap."

"What's going on here?"

"Uh, Ron mentioned that the reason he learned the disarming charm was that he practiced against Harry and got hit by the charm too many times." She said with her head down.

Felix looked at Ron, who was on the sidelines cooing, commenting, and scowling, and looked ridiculous.

But ... is it possible? Even he is not sure.

It's really an absurd point of view, totally for the people without a clear brain circuit.

He looked at his assistant, "So, you also believe it?"

Hermione said with some embarrassment, "At first I didn't believe ... it," but the number of young wizards running over to request mainly to practice against Harry grew, and she wavered.

She tactfully changed the subject: "Professor, everyone says you've mastered the Level Six spell." Hermione stared at Felix's expression, trying to gauge something.

"Is that so?"

"Yes!" Hermione said emphatically, "What do you think, Professor?"

"My thoughts, Miss Granger, are we going to be working late this weekend."

"Uh, what?"

"Grading the homework that was given in the last dueling class."

Hermione looked at him dumbfounded, and she couldn't help but look around at the hundreds of young wizards in the great hall, who were practicing their spells with gusto and enthusiasm.

In their eyes, it was a new and interesting enough game.

Occasionally, the great hall erupted with laughter when someone missed a spell or spewed out a cluster of dazzling sparks.

But in the joyful atmosphere, she suddenly lost that joy, only feeling a little disturbed.

After seven or eight minutes, Felix came up to the stage and ended the session.

"I have seen your progress, young wizards."

"The perfects of each house will collect the assignments which were given in the last class uniformly, and I will spare some time to advise one by one - if your data is not fabricated."

Many of the little wizards bowed their heads.

As the young wizards left the great hall, they had big smiles on their faces.

"Hermione, you don't look so good," Ron said.

He was in a very good mood, in fact, because of the Special Contribution Award, Ron became very popular these days, especially after resolving the trouble with Lockhart, and his detention was mostly lifted by Professor McGonagall.

" Oh well." Hermione walked away with her head held high.

"Harry, I think it's because of you, your Disarming Charm is much better than hers," Ron said to Harry.

Harry scratched his head.

The next morning, a piece of news spread throughout Hogwarts, overwhelming all other gossips.

"Gilderoy Lockhart: a false adventurer! About to face multiple trials.." A young wizard held the newspaper delivered by an owl and read the front-page headline aloud.