For Sarah.
It was Remus's idea. A legacy, or a test, or something like leaving a little piece of themselves to the school. Not like the Quidditch trophies in the glass cases inscribed with James and Sirius' names, or the initials they carved into the a crevice in the Whomping Willow because no one else could do it, or even Filch's detention records, whole boxes in his filing system devoted to their various and sundry misdemeanors. Those were fragments of who they were. But leaving the map was bigger than all of that. It was a piece of their truest selves, the people they were when no one was looking, the people they were when they were least afraid, most courageous, most together.
The map wasn't inscribed with the names James Potter, Sirius Black, Peter Pettigrew, and Remus Lupin; it belonged to Mssrs Moony, Wormtail, Padfoot, and Prongs. It belonged to the names that they chose for themselves, that they chose for each other, and it belonged to the version of themselves where they were all of the parts of themselves.
The person that Remus was with them, the person he put into that map, was a version of himself that wasn't ashamed of what he was. Moony took a curse, something dark and ugly and painful, and made it an adventure. The Moony in that map, he wasn't afraid to show his wry humour beyond his group of friends, wasn't afraid to be heard, or loud, or just a little bit mean sometimes when he got tired of being tired, when he got tired of being the quiet one, the smart one, the one professors appealed to to control his friends. Moony was allowed to be out of control the way Remus was never allowed to be out of control. And the Moony he was with the map was also the part of him that flicked James upside the head and pointed to the shifting footsteps of a first year when Malfoy or some other cronies had them cornered, the Moony who slipped on the Invisibility Cloak and drove them off, and also the Moony who slipped off the Invisibility Cloak and held out a hand to help that first year up off the ground, piling papers together and sweeping them off to the kitchen to let them in on a secret that they could call their own. Moony was also the guy who meticulously planned pranks, laying out the game plan with the map unfolded on his bed. Moony was the guy who grinned, joyous and quiet and still and in awe of the raucous laughter of his peers and thought I did this.
The person that Sirius was with them, he was kind and free and Gryffindor, and Padfoot was a name that belonged to him, and belonged in no way to his parents. Padfoot was not the scared boy who took his father's beatings or his mother's hateful words, and he wasn't the boy who stood by while they did the same thing to his brother. Padfoot was the person who took Remus' hand and didn't let go even as Remus was cringing away in fear when they told him they knew what he was. Padfoot was the guy who spend every spare moment for months, for years, learning magic he could get expelled, or arrested for, so that he could stand beside his friend and say "I am here for you. I will protect you." And Padfoot was the guy who nodded at Moony under the cloak and stood beside him to protect that first year, and who made them laugh before the tears were even dry on their face and who sat beside them the next morning at breakfast and didn't give a shit about the weird looks some of his peers gave him because James and Remus and Peter all sat right there beside him and that first year had never looked so happy. And Padfoot was the guy who tossed out every ridiculous idea he could think of because sometimes they became a reality, and he got to stand in the middle of chaos head thrown back feeling so free and so light and so happy that the name "Black" for a moment felt like nothing at all, and he got to look over at this friends, and not see any scars on Remus' face, only awe and joy, and think I did this.
The person that Peter was with them was happy. They took all the things that he like least, all the sneaky little thoughts, and his fears and his loneliness and they turned them into Wormtail and they made a rat into a symbol of their freedom, they made a rat into someone they depended on, they made a rat into their friend. Wormtail felt comfortable in his skin, Wormtail could say the bizarre stupid dark things that popped into his head and they would laugh and grin and Wormtail wasn't afraid to laugh with them, Wormtail didn't have a pit in his stomach all the time wondering if they were laughing at him, he laughed with them. Wormtail had never felt safer than in the company of a werewolf, a Grim, and a stag. And safety and friendship gave him the luxury of kindness, it meant that he could sit with that first year and show him all the best weird food combinations and tell him jokes and tell him that Malfoy was a jerk and it was all okay. Wormtail wasn't stupid, or a bad wizard, Wormtail had three best friends on his side who made him feel brilliant when he finally got it even though it took him ten times as long as they did, Wormtail was the guy who managed magic that grown wizards struggled with when he was fifteen and got to feel that glow any time he wanted and be reminded that he wasn't nothing, he wasn't no one, he was Wormtail of the Marauders. Wormtail got to set traps and watch them spring off just right into bright colours and screeches of joy and stand in the middle of laughter and watch his three best friends and know that he isn't nobody, because I did this.
Of all of them, James Potter was the one who was most like Prongs, and Prongs the most like James Potter. He had nothing against his name, he didn't need to hide from who he was, he didn't want to. The biggest, most important, most incredible thing about Prongs was the names that came before it, the hearts that twined around it, the people Prongs got to be a part of, the people Prongs helped discover, helped protect, helped grow. Prongs got to stand in a crowd of faces where only three others mattered and think we did this.
It was Remus' idea to leave the map. They were graduating soon, and even though Hogwarts would always be one of their homes, it was time to find a new one. Time to create a new one. Mssrs Moony, Wormtail, Padfoot, and Prongs had done everything and more, and it was time to bring the two parts of themselves into one, and they didn't need the map anymore. Holding onto it now would be greed, would be indulgence, clinging to the past instead of looking to the future. No, it was time to pass the map along to those who would someday earn it, use it, need it, the way that they did.
They planned it out perfectly; the trap, the prank, the chaos, it all worked out perfectly. Filch was so sure he'd finally got one over on them, stowing their funny little parchment away with his other confiscated goodies, and they sniggered and grinned at his retreating back.
And as we all know, the map stayed there for many years in silence, until freckled hands pulled it back into the light, just as a little extra laughter was going to be so badly needed. Just in time for it to lead a few lost souls back to themselves and each other, just in time for the Marauders to ride again.