the_debt_of_time

It was too late before Remus remembered the security measure put into the map.
"—and begs him to keep his abnormally large nose out of other people's business."
There was absolute silence, and Remus held his breath as he waited for Snape to
lose it. Unfortunately, Harry continued to read.
"Mr Prongs agrees with Mr Moony and would like to add that Professor Snape is
an ugly git."
Remus covered his face, repressing a guilty smirk.
"Mr Padfoot would like to register his astonishment that an idiot like that ever
became a professor."
Harry would pay the price for this. Remus knew he would.
"Mr Wormtail bids Professor Snape good day, and advises him to wash his hair, the
slimeball."
"Why you insolent little―" Snape began.
Remus took this as a cue to step out from the shadows. "Harry?"
"Professor?"
"Ah, good afternoon, Severus." Remus smiled politely, ignoring the red tint on
Snape's normally pale face. "Is everything all right?"
"I have just asked Potter to empty his pockets. He was carrying this," Snape spat,
thrusting the Marauder's Map into his hands.
Remus forced himself not to smile at the familiar parchment. He glanced it over
briefly as though it were nothing more than a piece of paper before he looked up at Harry,
noticing the way that the boy was shaking, whether out of fear of punishment or anger
over what had been said about James, Remus did not know. "Are you all right, Harry?"
"That remains to be seen," Snape answered. "Take a look, Lupin. This is supposed
to be your area of expertise. Clearly, it's full of Dark Magic."
Remus snorted as he recalled the variety of charms put on the map, none of which
were even close to being Dark in nature. The worst of the lot had been the insulting that
Snape had just been privy to.
"I seriously doubt that, Severus. It looks to me as if it merely insults anyone who
tries to read it." He shrugged his shoulders as he opened the parchment, letting his eyes
follow over the page as though it was currently insulting him. "I suspect it's a Zonko
product."