After the conversation with Professor McGonagall, Felix only assigned an assignment, with a title similar to the essay Harry and Hermione had written - when you are in danger, what can help you survive the crisis?

"Whether it is personality, knowledge, spells you have mastered, or things you carry with you, you can write it down." The new head of the student union passed his words to the selected students.

In the next week, many professors worked together to complete a major project, and he spent most of his time in the Room of Requirement, copying the magic and magic pipes above. Now there is only one step left -

Dumbledore and Felix stood in the empty room. There were no deformed hillsides and green spaces, no traces of different stadiums during the duel, and even the black suspended gate used to select students a week ago disappeared.

The only thing left in the room was the traceless extension spell cast by Felix, which made the interior space comparable to ten Quidditch pitches. If it weren't for the ideas of the other four schools, Hogwarts could have let them live here.

The professors cast many solid spells and protective magics, and every inch of this ancient castle was soaked with powerful magic. They added some additional defensive measures on this basis.

Now there are only two of them in the classroom, and they are having a serious conversation-

"What do you think?" Felix asked.

"It's worth a try." Dumbledore said easily.

"I never thought that I would embed my magic into the defense system of Hogwarts, and it will exist for hundreds or thousands of years..." Felix was in a trance for a moment, and when he came back to his senses, Dumbledore was looking at him with a smile.

"Let's get started, Albus, I'm afraid the students outside can't wait." Felix clenched his wand and said. Dumbledore

followed suit. He raised his wand and waved his arm like a conductor in an orchestra, communicating with this ancient castle in a way that Felix could not understand.

"Buzz~"

Not sure if it was an illusion, Felix felt that the castle under his feet came alive, like a sleeping dragon, slightly tilted, building nests and digging holes on it, and the small creatures parasitic on the scales found that the whole world had changed.

Clusters of magic power turned into entities, purple, blue, yellow, blue, bronze, green, gray... They gathered and quickly separated from each other, forming magical flowers.

"Felix--" Dumbledore said in a deep voice.

Felix understood that he needed to fix these magic powers and form a stable link-just like the Room of Requirement.

A fluffy silver ball appeared in his hand, like the seeds of puff grass, and like a collection of clustered neural networks. From time to time, light blue electric currents flashed. It slowly floated into the air, and then quickly expanded into a three-dimensional structure, occupying the entire spacious room.

Felix chanted a complex spell, allowing these tentacles and core nodes to blend into this space little by little. The tentacles, like synapses, absorbed the ownerless magic and stabilized the magic nodes above.

Then everything disappeared. Magic, tentacles, nodes... they were completely integrated into the room.

Felix switched perspectives, found those nodes, and hid them one by one, so that even powerful wizards could hardly find them. Dumbledore did the same thing. He also arranged stable magic channels from the authority that no one knew and belonged only to the principal.

As long as Hogwarts still exists, as long as it is still recruiting students, this place will never disappear like the Room of Requirement.

Dumbledore completed all this and found that there were four more thinking stone basins in front of Felix.

"What is this...?" He asked curiously, with some guesses in his mind.

"It's the memories of several professors." Felix said concisely.

He took a deep breath. Everything before was to create a suitable environment. The next step was the highlight. Although this step was not difficult, he couldn't help but get nervous.

Felix controlled the four mind stone basins to fly around, and it seemed that the room was divided into four areas, with a stone basin suspended in the center of each area.

"What's the point of doing this?" Dumbledore asked with interest. Even for him, this was a rare large-scale magic practice, a rare fusion of alchemy, mind magic, and transfiguration in the magic world.

"Add a little sense of ceremony." Felix smiled and said, then his tone became serious, "Then - the first administrator, seventeen-year-old Albus Dumbledore."

The stone basin on the left of the two people exploded, and countless dense silver clouds poured out from it. Then, a tall, thin, reddish-brown-haired young student came out.

He held a wand in his slender and dexterous fingers, and lightly drew it to the left and right, and the thick fog was divided into two. When he was young, Dumbledore had bright blue eyes, and his eyes flashed with kindness and mischief.

"Old friend, you didn't give me much knowledge. My head is empty. How can I face those troublesome students?" said the young Albus. Although he was complaining, he didn't seem to be bothered. Instead, he smiled and nodded at Felix.

Dumbledore looked at him, his eyes moist, and murmured: "This is when I just graduated. I was young and energetic, and I thought I had a bright future..." He shook his long silver beard and smiled and said: "Oh, I don't know if I didn't mention it. When I was young, I liked Bibi Multi-flavored Beans very much."

The young Albus Dumbledore was waving his wand, raising a silver wave. The mist was like solidified waves, fixed in the air. Then, they deformed and formed an open-air square with a lot of red and gold decorations dotted around.

Felix and Dumbledore looked at each other for a while, turned to the other side, and Felix whispered: "The second person who selflessly provided memories-Minerva McGonagall."

The second thinking stone basin exploded into powder. A young and beautiful lady stood there. She had thick black hair, about thirty years old, and green eyes. This was the young Minerva McGonagall. She looked more like the Transfiguration Professor at Hogwarts. She had a serious expression, her hair was piled high, and she wore a pair of square-framed glasses.

"How interesting..." She looked around and pursed her lips in a signature way. "Let me think about what I need to do. Minerva left me a list of tasks."

Then, she stood still.

The third person to appear was the young Filius Flitwick. He was also much younger than the current Hogwarts Charms Professor. He had not yet worn the gold-rimmed round glasses, and his wrinkles were much less. He was wearing a solemn and rigorous suit.

According to him, this was the clothes he wore when he won the Wizard Duel Championship.

"Oh, Felix, Albus..." The young Flitwick bowed slightly and waved the wand in his hand gracefully, "Welcome. I don't think you are in the mood for a duel for the time being, but I am here, waiting for you at any time."

The last stone basin exploded, and the young Felix walked out. He looked exactly the same as he does now, but his expression was a little frivolous. He looked at Felix and pointed at him, "I need to talk to you. You have put too many restrictions on me."

"Oh, you don't need it." Felix muttered, letting layers of silver mist cover him.

...

Felix said to Dumbledore: "They will not appear often, but as managers of this secret place. Their task is to make this place more dynamic and the training scenes more controllable. Of course, I am talking about after the training."

Dumbledore nodded slightly: "You have told me all this, I have no objection."

They walked out of the room together. More than 20 students were waiting outside anxiously. A little girl screamed: "Why is there no me on the list? Why?"

Professor McGonagall was comforting her and said: "Greengrass, you are too young, it is really not suitable..."

"I am the champion! Champion!" Astoria shouted.

Professor McGonagall looked at her with a headache. At this time, Dumbledore came over and said gently: "Are you little Astoria? Your father sent me a letter. Let's go and see it together. By the way, I can recommend a few desserts..."

"Really?"

"Professor McGonagall can testify for me..."

McGonagall rolled her eyes, but finally solved a problem. She said to Felix: "These students are left to you, Felix, I think-"

She thought about it and didn't say anything. He turned and left.

Felix looked at the young faces and said, "Okay, students, bring your papers and follow me in."

He took a few steps, stopped, looked at the half-open door, pulled out his wand, sketched in the air, and a line of gold-plated letters appeared above the door, "Classroom 7."

Harry, Ron and Hermione looked at each other, and Harry shrugged, "This is now worthy of the name."