It took them more than a year to finally finish the Map.
A year spent combining their knowledge to render the Hogwarts Castle on the enchanted parchment that they created after intensive research, tireless exploration of the castle, countless amounts of experiments and multiple failures to finally produce the final but imperfect result.
However, it turned out that there was a defect in the map.
A defect that went by the name 'Hermione Granger'.
.
.
.
"Who could she be Prongs?" Sirius asked as they hurriedly walked down the hallway on their way towards the mysterious name that he could see over James' shoulder while his friend carried the map in front of him.
"I don't really know Padfoot," James replied. "All I know that I have been seeing her name pop up in the map of the castle and we have already proven that she is not a ghost like we first assumed. The Hogwarts' ghosts have certainly clarified that fact."
"If not a ghost, then who or what is she? Why is she on the map?" Sirius said as he tried to catch up to James who had picked up his speed.
They were both nearing the location where the mysterious name on the map was headed.
"I am starting to suspect that this is just a flaw. A defect that we have not foreseen when we were making the map," James answered just as they made a left turn and came to a complete halt at the place where the mysterious name had also stopped on the map where they were currently facing.
James and Sirius looked in front of them but couldn't see anyone there.
However, when they both looked back at their recently created Map, they were shocked to see some words appearing right next to the name 'Hermione Granger'.
Hello? Is someone there? The words appeared on the map in black ink, which they could only assume was the girl trying to communicate with them.
James and Sirius exchanged a glance of surprise.
Even though they could not see anyone in front of them, James couldn't help but ask out loud, "Who are you?"
Then, he watched in complete stupefaction when his question appeared in the Marauders Map in black ink as well just next to his name.
Meanwhile, somewhere in the future, Hermione Granger stared at the map on her hand, which she had confiscated from Fred and George Weasley two days ago.
The same enchanted map that revealed to her mainly after a paper cut had caused her blood to seep on the enchanted parchment.
As she stood there on the empty hallway, Hermione could only watch in mute shock as the words appeared on the map just next to the name 'James Potter'.
Who are you? Hermione read.
.
.
.
AN: Another idea that can turn into something more. I made .gif edits for this fic, which I plan to do if I continue with it. The .gifs will have the moving images of writings and the names of the characters. You can see the .gifs on the fic itself on my AO3 account. I intend to do more of those moving map if I do continue with the story.