Note: A little gift on my part, dedicated to three persons in particular – the Messrs. Padfoot, Prongs, and Wormtail of our little group. ^^ Cheers! (Yes, Kayti, you are Wormtail. Sorry. +Grins mischievously+)

It was Angelina's birthday.
The second year laughed merrily as the Weasley twins sandwiched her between them, their shoulders knocking playfully into hers simultaneously. "Three cheers for Angie, eh, you lot?" George shouted, to much agreement. "The big one-three, three an' ten – I say, you're not going to shrivel up and die on us anytime soon, are you?" Fred yelled gleefully, winking happily.
The two first years melded well enough with the second years – with any year, for that matter. The Weasley twins grinned and laughed as easily with seventh years as they did with their fellow eleven-year olds.
The boisterous group of Gryffindors flowed through the halls, giggling, jostling each other about, and (unfortunately) making a mess, due to their muddy shoes from romping out on the grimy grounds of October. This, of course, brought Mrs. Norris bounding down the hallways instantly, growling in delight at the sight and prospect of catching them in action, and springing back towards Filch's office.
This, however, did not fail to seize their attention – George saw the grubby cat first, and shouted, "Oi!" All eyes reverted towards the feline, and Fred nodded with mock-grimness. "We'll take care o' this, ladies an' gents," he said dourly, a smile only just twitching at the side of his lips.
"Ay," agreed George. "Best make your getaway, dears..."
Katie Bell opened her mouth in protest, but everyone scurried away just the same. Fred glanced at his brother. "Eh... What is it exactly that we plan on doing?" he asked.
"Er..." George scratched his head. "I dunno. What do we generally do in one such a situation, dear brother?"
Fred blinked and thought for a moment. "Dungbomb?" he suggested. George nodded agreeably in concurrence. "Dungbomb."
In scarcely half a minute's time, Filch was indeed sprinting down the corridor, beady eyes searching for any remote possibility of a broken rule, sacrilege to his precious, immaculate halls.
Filch was not pleased.
"Who – did – this –" he said in a slow, dangerous whisper, his nostrils slammed with the sudden scent of manure. "Dungbombs – mud – in – my – CORRIDOR."
The caretaker leered around, and found two unusual suits of armour standing by. They were uncommonly close together, breathing, and looked remarkably like the Weasley twins. Goodness, what sort of armour could they be? Filch wondered, as he marched, seething, towards them. He stood there, glaring, his arms folded over his chest, waiting for them with a savage scowl. George sneezed.
"George!" Fred hissed, elbowing his brother in the ribs.
"I'm sorry," George replied as he rubbed his nose. "I can't help it. I think I'm allergic to Filch – I mean, Dungbombs."
Filch seized them both by the collars directly after they burst into laughter simultaneously. The caretaker, however, did not seem amused. He dragged them off towards his office and forcibly sat them down on the two chairs in front of his desk.
"I say," said George. "That's child abuse, that is."
Filch did not respond. He simply continued to glower at them.
"Mud," he murmured in a soft voice. "Mud. Dungbombs. In my corridor. YOU."
"Oughtn't he to use conjunctions?" piped Fred.
"Naw, I don't think so," George replied, shaking his head. "He seems too distressed, brother."
"DETENTION!" Filch shrieked, standing abruptly from his seat and banging his palms onto the surface of his desk. "DISEMBOWELMENT! EXPULSION!"
"Still distressed," said George with a concerned whistle. He did not add that he noted a particular cabinet marked 'Confiscated and Highly Dangerous'. He bumped his knee into Fred's, discreetly nodding his head towards the filing cabinet. Fred blinked owlishly, slightly puzzled, but his expression changed, only slightly, as it dawned on him.
"EXPULSION," repeated Filch, his voice growing softer, and more perilous.
"Argus," said George concernedly as he leaned forward and patted the caretaker's hand, concealing his other as it reached for another Dungbomb. "Dear Argus – we've been through this so many times. Darling, at this point, it is merely ceremony. Why don't we skip this, and we'll go out and buy you a butterbeer? Okay?" He smiled with all the air of a mother comforting a rebellious three-year old.
Filch's face reddened with rage, but it changed to an air of surprise as George dropped the Dungbomb. A massive cloud of smelly, green smoke exploded behind George's chair, and Fred sped over and slid the drawer open, grabbed a sheet of it's contents, and banged it shut again; before the smoke had cleared, Fred was safely back in his chair.
Filch coughed angrily, shielding his nose from the fresh smell. Fred and George leapt from their chairs and bowed in unison.
"Goodness, look at the time –"
"– We really must be going –"
"– Can see you're busy –"
"– Wouldn't DREAM of taking another minute of your time –"
"– Must dash!"

...

"'Highly Dangerous', my ASS."
Fred and George peered down at the piece of parchment, Fred with a look of disgust, and George with an expression of perplexity. They were safely up in their dormitory, lying on their bellies on George's bed. "Godric, what'd he take it for?" asked Fred aloud for the umpteenth time. "It's just a blank piece of PARCHMENT!"
George poked it with a finger as Fred sauntered off the four-poster and looked up at the ceiling, as 'though searching for an answer. "This is driving me MAD," Fred cried. "It doesn't DO anything! But why would he have it if he DIDN'T?"
George brandished his wand. "Only one way to find out, eh?"
Fred glanced back and moved back towards his brother, suddenly interested. "I'm listening," he said with a grin.
"Aparecium!" George said, prodding the vellum with his wand.
A spidery text began to unfold, unveiling a set of words.
'Mister Padfoot would like to point out that he is not an absolute buffoon, and that it will take a LOT more than that to – shall we say, divulge the beauteous secrets that this supposed "blank piece of parchment" withholds.'
'Mister Prongs aspires to make known his utter agreement – except in the case that Mister Padfoot is not an absolute buffoon. Mister Prongs is not so wholly certain of that.'
'Mister Wormtail intends to indicate the fact that the intruders are total idiots if they think that Messrs. Prongs, Padfoot, and Wormtail would be so foolish as to do something like that.'
'Mister Moony desires to rebuke Mister Wormtail for leaving Mister Moony out in his list, to add that he concurs with all above statements (including Mister Padfoot's conceivable buffoon-ism), and to muse upon the fact that Messrs. Moony, Wormtail, Padfoot, and Prongs are all speaking in the third person.'
Fred and George blinked owlishly in unity. "Godric," Fred breathed in a low tone. "It TALKS."
'Messrs. Moony, Wormtail, Padfoot, and Prongs do a lot more than TALK, Mister Intruder,' wrote the hand that apparently belonged to Mister Wormtail.
'Mister Moony asks whom Messrs. Moony, Wormtail, Padfoot, and Prongs might be conversing with.'
"Eh... Fred and George Weasley?" George answered dubiously.
'Mister Padfoot wishes to extend his most gracious welcome to Messrs. Weasley – unless they're Slytherin. Then they can both boil their soppy, greasy heads, the gits.'
"We're not Slytherins!" cried Fred indignantly. "Gryffindor, sir – Gryffindor, and no other!"
'Mister Prongs would like to apologise for Mister Padfoot's error –' Padfoot's hand began to scribble a protest, but it was hastily written over by Prongs, ' – and would like to ask how Messrs. Weasley came across this brilliant piece of mastery and magistry, if Mister Prongs might be so bold as to ask.'
"Er..." George paused. "Filch's office. We sort of – stole it."
'Mister Moony would like to put an especial emphasis upon the fact that you stole it, and from Filch's office, did Mister Weasley say?'
"Well, yeah," said Fred. "We nicked it from old Filch, if that's what you mean."
'Mister Padfoot proposes to ask why Messrs. Weasley were in Filch's office.'
The twins exchanged hesitant glances. "We... Set off a Dungbomb in the corridor."
'Mister Moony aims to beg the pardon of Messrs. Weasley, but proceed to express his disgust for such a lowly act of legerdemain – Mister Moony means to censure Messrs. Weasley for the shame, Messrs. Weasley.'
'Mister Prongs has it in mind to remonstrate against such admonishments, and commend Messrs. Weasley for such a trick. Mister Prongs would like to add that it was doubtless practical for the particular situation.'
'Mister Moony would like to withdraw his former statement, and begs pardon from Messrs. Weasley.'
The Messrs. Weasley looked at each other with wide eyes of doubt. Fred's brow knitted with displeasure. "What exactly are you lot on about, anyways?" he questioned. "What's this thing DO? I don't want some bloody paper that talks back."
'Mister Padfoot wishes to tell Messrs. Weasley that this is no mere PARCHMENT. This,' his text increased slightly in size with pride, 'is a map.'
"A map of what?" George put in, his voice heightened in pitch, and sounded rather ignorant.
'Mister Wormtail wants to say that it is a marvellous, spectacular, brilliant, stupendous, superlative map of Hogwarts School of Witchcraft and Wizardry.'
'Mister Moony has it in mind to kick Mister Wormtail in the shins for revealing the damn secret, the great prat. Mister Moony would also like to add his astonishment that Mister Wormtail knows so many synonyms for basically the same adjective, and frowns upon the sheer redundancy of that sentence.'
'Mister Prongs prompts to defend Mister Wormtail by saying that Mister Prongs feels that Messrs. Moony, Wormtail, Padfoot, and Prongs can probably trust Messrs. Weasley – Mister Prongs once knew a Weasley, and that particular Mister Weasley was a fairly good chap.'
'Mister Padfoot, having heard Mister Prongs's piece, decides that Messrs. Moony, Wormtail, Padfoot, and Prongs should tell Messrs. Weasley the wondrous secret of said map, as Messrs. Moony, Wormtail, Padfoot, and Prongs very may as well do, as Messrs. Weasley already know it is a map.'
'Mister Moony resigns to Messrs. Prongs and Padfoot's conclusion.'
'Mister Wormtail, being fairly outnumbered, which is jolly unfair, acts in accordance with Mister Moony.'
George raised an eyebrow. "So... What's that mean?"
Fred rolled his eyes. "They're going to tell us the fabulous 'secret of the map'. 'Though it can't be THAT great, Godric knows." He crossed his arms. "So, what's it do, then?"
'Mister Wormtail says that Messrs. Moony, Wormtail, Padfoot, and Prongs have already explained that particular aspect – Mister Wormtail repeats that it is a MAP.'
'Mister Moony adds that it is a map of HOGWARTS.'
"'Ow do we see this map, then?" asked George.
'Mister Padfoot scoffs at the sheer simplicity. Mister Padfoot tells Messrs. Weasley that Messrs. Weasley have only to point at the map with Messrs. Weasleys's wand and say, "I solemnly swear that I am up to no good".'
'Mister Prongs would like to add that it might be recommended to wipe the map afterwards, else someone might chance upon said map and find it's secrets.'
'Mister Wormtail adds that "Mischief Managed!" is all one needs to say in order to do so.'
Fred and George exchanged glances once more as the revelled Marauder's Map unfolded before them on the formerly blank parchment. The passageways, secret corridors, and undisclosed nooks of Hogwarts lay on a piece of parchment that could be easily carried in their pocket. Fred grinned. This was going to be a fun year.