Felix was pondering this question until the next day.

He just came back from the Room of Requirement, in this hidden room, he tried to use various methods to make these two unrelated memories get along, but all ended in failure.

Therefore, Felix instead began to research the Room of Requirement. He repeatedly passed across the ' Troll Tapestry' on the eighth floor, mentally pondering the various needs.

He had researched this mysterious room earlier, but it was all about his own needs, and except for the outrageous requests, requests that were regular and in line with the perception of the wizarding world were basically met.

So he intends to try out the Room of Requirement from someone else's perspective.

Starting with a simple idea like 'hiding something', he kept trying all kinds of possibilities and even hit on various professors.

For example -

"I want to access the Severus Snape's secret stash ...."

Naturally, there was no response at all.

It seems that Professor Snape, when he was a student, did not have the habit of running around with prohibited items in his pocket, he thought with some relish.

Felix found joy in this 'game' - it gave him a sense of time and space dislocation and conversation with a distant young acquaintance. He tried with relish, this time anchoring the principal of Hogwarts -

'The room where Albus Dumbledore hid his stuff.'

'The room where Albus Dumbledore practices his magic.'

'The luxurious sleeping room where Albus Dumbledore slept.'

'The luxurious washroom that Albus Dumbledore ever used.'

Felix was about to continue the next topic, but a door surfaced on the wall very abruptly.

The door, which opened from left to right, looked very luxurious and was decorated with various golden carvings and patterns.

"What did I just mention?" He obviously froze for a moment, and then pushed opened the door and walked in.

Inside was a very luxurious lavatory, decorated with a variety of exquisite and luxurious chamber pots.

Felix silently retreated.

He was debating whether to continue, when not far away came a noise, under his gaze, Trelawney appeared dragging a box.

The box made a " tinkling " sound of glass clashing, very clear in the corridor.

Trelawney did not wear those mysterious-looking accessories but wore a crumpled pyjama, her hair also messily braided up, looking unkempt.

She also saw Felix.

Trelawney's expression quickly went from bewilderment to horror, but she did her best to remain calm and said, "I'm glad to see you here, Felix, fate has brought us together this early in the morning."

"So you don't have any preparations at all and despise the fate?" Felix said, pointing to her costume.

Trelawney retorted angrily, "Don't despise fate!"

"Well, besides fate arranging for us to meet, what else do you plan to do by the way?" His eyes fell on the box, which contained seven or eight bottles of sherry.

"Oh! I, I think I can hide ... to put something that I can't use by the way."

The two men then fell silent.

Felix felt that she wanted to escape from here very badly, and he did not want to stay much longer, but there was one more question to be cleared up.

"You know about the Room of Requirement?"

"What? Oh, yeah." She said absently, "I use it to keep my stuff, and frankly, my office is a little small, and I haven't had a pay raise over the years ..."

Felix quickly excused himself.

After leaving the eighth floor, Felix ran to the great hall for breakfast and then made his way to the Ancient Magic rune classroom in a hurry.

On the way, his thoughts whirled, thinking about memory magic for a moment and the Room of Requirement for a moment.

"Hey, look out, Miss Lovegood."

In his lingering glance, he caught a glimpse of a figure approaching straight ahead, and he stepped aside to avoid her.

It is Luna Lovegood, holding a piece of parchment in her hand and looking at it intently, but Felix notices that she is holding it upside down.

"It's you, Professor Hap." She lifted her head and looked at him with wide eyes, "It's good to see you."

"So am I, Miss Lovegood," Felix replied helplessly, the second time today he expected to hear that from an acquaintance.

She waved the parchment in her hand, "I'm reading the leaderboard, and I'm not going to bump into anyone, don't worry." She said.

Felix choked a little, he just wanted to remind the little girl, now he could only change the subject and ask: "Anything interesting?"

"Very interesting indeed ..." Luna showed him the parchment - still crooked - and she said chirpily, "From this angle, here," her finger traced an arc across the paper, "connecting the Ravenclaw names, doesn't it look like an eagle?"

"Well ..." Felix scrutinized it for a good half-minute, and he said, "It does look like that."

Luna immediately raised her eyebrows and smiled.

'Clear-thinking little girl, worthy of Ravenclaw.'

Felix thought to himself as he watched her distant back.

...

As he stood at the podium, looking at the young fourth-year wizard, ready to start the lesson, a light suddenly flashed -

He had always had a question about who had built the Room of Requirement.

Even he could not see through the entire structure of the room, was it possible for an ordinary wizard to do this? But Hogwarts had been around for a thousand years and had produced many outstanding wizards, so he couldn't say whether such a person existed.

So this suspicion was once given up by him.

However, he suddenly fixed on one person at this moment, Rowena Ravenclaw.

Could it be that she built the Room of Requirement?

Thinking from this perspective, a lot of things are clear -

The magical power supply of the Room of Requirement is based directly on Hogwarts, and Rowena Ravenclaw is one of the founders of Hogwarts and naturally has this authority.

The Room of Requirement has no fixed form and will always change to match the needs of the person asking for help, which must contain powerful memory magic, transfiguration magic.

And from the manuscript Felix saw, Rowena Ravenclaw did meet this requirement.

Also, the rumours of the Chamber of Secrets that have been circulating for a thousand years, the only ones most famous for this are Slytherin and Ravenclaw. Now that Slytherin's Chamber of Secrets has been found, what about Ravenclaw's Chamber of Secrets?

The young wizards on the stage saw Professor Hap with a smile on his face, seemingly ready for class, but he suddenly fell silent.

" Professor?" A young wizard bravely asked.

"Oh?" Felix snapped back to his senses and suppressed his thoughts as he turned to the young wizards and said, "Now, let us begin today's lesson ..."

"Please turn the book to page 147."