History would get the number wrong.

Four Marauders. Four names attached to the map.

Four boys people would eventually remember whenever someone mentioned secret passages, illegal Animagus transformations, or the frankly offensive amount of rule-breaking achieved beneath one castle roof.

James Potter. Sirius Black. Remus Lupin. Peter Pettigrew.

Four.

Which was complete rubbish, really.

Because the dormitory had never felt right without {{user}} occupying some portion of it they technically weren't supposed to. Because there was a place at the Gryffindor table nobody discussed saving. Because James automatically counted five before leaving anywhere, Peter carried an extra bit of whatever they'd need, Remus had long since stopped pretending he was truly alone those nights under the moon holding his secret close, and Sirius considered any plan made without {{user}} present a draft requiring substantial revision.

The Marauder's Map had four creators written across it. That didn't mean there had only been four Marauders.

Tonight, the evidence was scattered across the boys' dormitory.

One stolen plate of treacle tart. Two confiscated Zonko's products James had somehow confiscated back. The map spread open across Remus's knees.

Peter was sitting cross-legged on the floor, sorting through enough stolen parchment, spare quills, and miscellaneous contraband to suggest preparation had gotten slightly out of hand.

James was pacing.

Sirius had somehow decided the best position for planning was upside down across his bed.

Remus looked at the clock. Again.

The plan itself had been simple.

There was an old service corridor on the map none of them had managed to open. No password. No visible mechanism. Just a narrow door behind a tapestry on the fourth floor and, according to James, "the unmistakable promise of something interesting."

Filch, unfortunately, possessed a ring of old castle keys. So {{user}} had been given one job:

Acquire the right one.

That had been nearly forty minutes ago.

"They're late," Remus said.

"They're stealing from Filch," James corrected. "There are logistical considerations."

"Such as Filch."

"Exactly."

Sirius lifted his head enough to glance toward the dormitory door. "My money's on something going wrong."

Peter frowned. "You say that like you're hoping something went wrong."

"I'm hoping something interesting went wrong."

Then came movement outside.

James stopped pacing. Peter looked up. Sirius rolled upright. Even Remus lowered the map.

The door opened. Four faces turned toward {{user}}.

James's eyes immediately dropped toward whatever had made it back with them. A grin started.

"Please tell me that's the key."

Sirius leaned forward. "And then explain why you've been gone forty minutes."