The Flaw in the Marauder's Map

William and his companions looked at the map with a sense of helplessness.

The map maker seems to have thought of all the decryption spells, enough to prevent the little wizard from forcibly cracking the map.

However, without knowing the secret order, one cannot freely use this map, nor can one monitor Snape's medicine storage room for an extended period of time to find out who attacked him.

William stared at the map without saying a word.

George comforted him, "It's alright, William. At worst, we can just increase the frequency of our pranks. It'll be slower, but we'll eventually reach the thousand small goals outlined on the map."

But William's dark green eyes remained fixed on the map, as if he were deep in thought.

"What's wrong, William?" Cedric asked. "What's on your mind?"

"Indeed, there are some." William asked, "I recall there wasn't just one way to obtain a secret order, was there?"

George stroked his chin and said, "That's true, but William, I don't think this map has anything missing."

There is certainly more than one way to crack this map.

The fastest way is to use powerful magic to break it directly.

But that requires a very powerful Confundus Charm to confuse the map, and William and his three companions don't even know how to use Confundus Charm, let alone confuse this map.

The second way to crack the code is to complete a certain number of challenging pranks according to the map's requirements, and the map will automatically reveal the secret code.

This is the dumbest way.

It was also the only method that they were confident about.

If the Weasley Brothers continue their high-intensity pranks, they should be able to complete this task next year.

The third method is to find secrets that even the map's creator didn't know.

As George said, it's difficult!

This map demonstrates the creators' understanding of Hogwarts; they were very confident that Hogwarts held nothing back from them and had no secrets whatsoever.

They were also confident that there were no unexplored areas.

If someone manages to find the secret they haven't discovered, the map will automatically reveal the secret code.

However, since William brought it up, he must have some ideas.

George took out his wand and pointed it at the parchment. "Map shows."

Soon, fine lines of ink, like a spider web, began to appear from where the wand had just touched.

These lines converge and intersect, extending to every corner of the parchment; then, writing begins to appear above the parchment in large, curved green letters:

"Magic Pranks - Marauder's Map"

Proudly presented by the Marauders — Moony, Wormtail, Padfoot, and Prongs.

Below was a line of small, bright green text. "The Prongs greets Mr. Mr. Weasley. Please give the secret command."

"I'm going to play a prank," Fred said seriously, then flashed a fawning smile. "Mr. Prongs, you've always been so handsome. I think a lot of girls liked you back in school."

As if an invisible hand were writing on the parchment, words appeared on the map. "Padfoot stiffened slightly, indicating agreement and anticipation."

George laughed, "Of course, Mr. Padfoot is also very handsome."

The words reappeared on the parchment. "The secret order was wrong, but Prongs and Padfoot approve of Mr. Weasley's assessment."

"Therefore, you will be granted 55 minutes of map access, so please make the most of your prank time."

The writing had completely faded, and the map detailed every aspect of Hogwarts Castle and its various locations.

William stared at the map.

Tiny ink dots moving along the map, each dot marked with a name in tiny letters.

A small ink dot in the upper left corner shows Professor Dumbledore pacing in his office.

Filch's cat, Mrs. Norris, stopped in the Seventh Floor hallway, seemingly sniffing the floor.

The mischievous ghost Peeves is hopping around in the prize room.

However, the names of William and the other three were not displayed on the entire map!

It's as if they've been wiped off the map!

William laughed, "Just as I thought."

The group gathered around the map, and Cedric quickly noticed the anomaly, exclaiming in surprise, "Our names aren't on it?"

This is the first time something like this has happened.

George had a stern face, looking extremely serious, just like Professor McGonagall.

He had always thought that this map was omnipotent, and might even be a treasure left behind by the Four Founders a thousand years ago, just like the Sorting Hat.

Of course, if it really is a treasure left behind by the Four Founders, then the one who made this map was undoubtedly Gryffindor.

But it seems that's not the case now!

George was disappointed, feeling a sense of faith crumbling; he had always regarded the Marauders as his mentors.

Fred sighed, "It seems Prongs and the others haven't found the Room of Requirement."

Cedric stared at it for a while and said, "It's not necessarily that the Room of Requirement wasn't found; it's also possible that this room has been enchanted by ' Unplottability '."

"Unplottability" is a special kind of magic that can be used to hide a certain area of the world.

Any location that is "Unplottability" is either not directly visible to people or simply cannot be marked on a map.

Unplottability locations are usually wizards' residences and magic schools.

Beauxbatons Academy of Magic, Durmstrang Institute and Wizardry, and Hogwarts School of Witchcraft and Wizardry are all Unplottability. They use powerful magic to protect their students and the secrets within, preventing Muggle and dark wizards from discovering them.

Similarly, the famous Azkaban is located on an "Unplottability" island in the center of the North Sea, isolating it from the rest of the world.

William shook his head. "This house may indeed be ' Unplottability,' but I feel it belongs to the Marauders. I didn't find the Room of Requirement."

How so?

William analyzed, "You see, perhaps many years ago, there were four students who, like us, were eager to discover the secrets of Hogwarts."

"Then let me ask you, George, if you felt you knew all the secrets of Hogwarts, what would you be thinking while out for a night stroll?"

"I would like to find a 'secret passage or room that I have never discovered before'."

William laughed and said, "That's right, it only appears when you really need the Room of Requirement."

"You are trying to find a room that you have never discovered before. If the Room of Requirement responds to your request and appears before you, at that moment, the room is no longer a room that has never been discovered."

This logical paradox constitutes an invalid command, which is why the Room of Requirement is never actually displayed in front of just a few people.

(P. S. First update, please vote!)

(The above is just my own analysis on PS2. No one knows everything about Hogwarts, not even the Marauders.)

The most direct evidence is in Chapter 17 of the Order of the Phoenix, where Harry seeks a secluded place for D. A. to practice Defence Against Dark Magic.

Sirius's first thought was the Shrieking Shack, then the secret passage on the fifth floor, but both were rejected. He couldn't think of any other better place.

If he knew about the Room of Requirement, his first thought would definitely be the Room of Requirement, like Dobby.