In the evening, Felix was walking in the corridor under the castle, carrying a candy box.

"Professor Happ—"

Felix looked at Draco Malfoy and the two big boys behind him and nodded at them.

"Professor, I have mastered a new rune." Draco said excitedly. He stretched out his right hand, and the Ouroboros ring on his index finger began to move, spitting out a light blue rune symbol from the snake's mouth.

He held the rune symbol, his face flushed slightly, and after seven or eight seconds, the light blue symbol turned into a handful of gurgling water.

"You're making rapid progress. I remember this is the sixth rune you've mastered?"

"Yes, professor."

"Well," Felix thought for a moment and reminded, "Spend more time on the runes we talked about in the previous meetings. They will be very useful."

Draco was stunned for a moment, "I see, professor."

Felix continued to move forward with the candy box. Malfoy shouted behind him, "Professor Hep, are you going to the dean's office? I just checked and the door is locked."

"Maybe Severus is brewing potions? Anyway, I'd better go and take a look." He said vaguely.

Draco looked at Professor Hep's receding back and said to himself, "I always feel that the professor is a little strange today?"

Crabbe and Goyle giggled ingratiatingly. Draco was used to this kind of scene. He shrugged and led the way to the lounge. "What do you think about Daphne's sister, the one named Astoria..."

In the office of the Potions Professor, Felix tried a few unlocking spells and opened the door.

He walked in as if no one was around. This place was not small. In addition to the office room, there was also Snape's private storage room and the innermost bedroom.

He walked through the dimly lit glass specimen wall and pushed open the bedroom door. The flowers inside were blooming luxuriantly.

"Severus, I am trying to save your face in front of your students. If they see you being brought back by the Levitation Charm... Tsk tsk!"

He opened the candy box - the same one Sirius had used, and inside was a palm-sized unconscious person, Severus Snape.

"Mrs. Rosmerta was curious about how a living person like you could suddenly disappear. Fortunately, I covered it up."

He tapped his wand to restore Snape to his original state, and then used the Levitation Charm to put him on the bed, with Snape's wand placed next to the pillow.

The next day.

Felix kept the Weasley twins after the fifth-year Ancient Runes class.

"Marauder's Map?" The twins looked at each other and communicated with various small movements.

Felix could see that this was a possibility!

Fred hesitated and said, "Professor, we--"

"--got it from Mr. Filch." Felix nodded.

"Uh..." Fred's expression was a little embarrassed, "You know everything?"

"I know a little bit, but what I care most about is whether it is still in your hands now?"

"We gave it to--" George said, Fred quickly covered his mouth, winked desperately, and then said to Felix embarrassedly, "We gave it to a friend. If you need it, we will find it back for you. Don't worry, it will not delay anything."

George blinked and realized that they gave the Marauder's Map to Harry, and Harry went to Hogsmeade Village with the help of the Marauder's Map, but they couldn't go into details about it.

Although they often violated school rules, they should try to avoid exposing their own shortcomings.

"You should know Moony, Wormtail, Padfoot and Prongs, right?" Felix asked.

The twins widened their eyes, and Fred said in surprise, "You know this too? Professor, you are not one of these four people, are you?"

"Or the previous map user?" George guessed.

Felix smiled, "I didn't have this opportunity when I was in school, but I know two of them. Today I came to you on behalf of one of them to borrow the Marauder's Map for a while. Don't worry, I will return it to you..."

Fred's eyes were shining, and he kept rubbing his hands: "Oh~ Professor, can you introduce him to us?"

"Yes, which one is it? We owe them a lot of favors!" George asked eagerly.

"I can only tell you that the man's code name is Bigfoot. As for whether he is willing to meet you," Felix looked at their eager faces, "It's definitely not possible now. It's not convenient for him to show up."

He looked at the twins with great interest. Their expressions were like pilgrims. It can be seen that although they have never met, the two have regarded the map maker as a predecessor and role model for pranks.

They ran away, "Professor, we're leaving first, to find the map!"

At noon that day, Felix got the Marauder's Map. It was the first time he saw the full picture of the map. Before that, he had only heard of it but never seen it.

It was a rather old piece of parchment. It didn't look big, but it was actually folded up layer by layer. When it was unfolded, it looked like a tablecloth.

"This is the secret of our success." Fred patted it affectionately, sighing, with an expression reminiscing about his youth.

Felix smiled and said nothing. He tapped his wand on the map and said to himself: I solemnly swear that I am up to no good.

This was the password he got from Sirius. Sirius could only stay in Grimmauld Place now, but Felix secretly connected the fireplace in his office to the old Black house so that he could read books in his spare time. He opened it whenever he wanted and sealed it when not in use to avoid being noticed by the Ministry of Magic.

Lupin also agreed to let Sirius visit him on weekends. When he left, Sirius and the house-elf old Kreacher were busy cleaning.

In Sirius' words, "At least clean up the living room and prepare two bedrooms for guests."

With the command and the wand, dark ink lines emerged on the blank parchment like spider webs. They intersected and extended with each other. With just a few strokes, they outlined the buildings in Hogwarts Castle and some surrounding venues, including the greenhouse outside the castle, Hagrid's hut, and the edge of the forbidden forest. All kinds of details were available.

The most shocking thing was the huge number of ink dots moving in a disorderly manner on the map, and each ink dot had a name marked in tiny letters next to it.

Felix found his name at first glance. Next to his name were two other small dots, which read Fred Weasley and George Weasley.

He looked all the way. Dumbledore was in the study, Snape was in the Potions classroom, and Professor Sprout was in the greenhouse. He also wanted to see the location of the Room of Requirement, but he couldn't find it. It might be blocked. He had expected this and was not surprised. However, he saw Trelawney wandering around in her attic alone. From the movement trajectory of the ink spot, he guessed that the Divination professor seemed to be doing some kind of dance.

A line of cursive words began to emerge in the middle of the parchment: Messrs. Moony, Wormtail, Padfoot, and Prongs, suppliers of aids to magical mischief makers, proudly present the Marauder's Map.

Felix stroked the map for a long time before he came to his senses.

"It's a very clever structure. I need to take a closer look..."