Disclaimer: I own nothing that you recognize.

A/N: This is a weird little idea that occurred to me the other day: what do you get if you combine the Marauders and Fred and George Weasley, the most talented troublemakers of two different generations? Answer: TROUBLE!

This is roughly set around late October of The Prisoner of Azkaban, though some things may end up slightly AU later. It's kind of hard to make something involving time-travel fit well with existing events.

Chapter One – Essence of Mayfly

George Weasley lounged at his ease against a table, waiting for his twin, Fred, to return from raiding Professor Snape's supply cupboard.

Fred and George Weasley were in their fifth year at Hogwarts and should have been studying hard for their OWL's in the run-up to Christmas, along with the rest of their year. However, the Weasley twins had always found more interesting ways to spend their time than on study and their favourite activity was inventing new and ever moredevious ways to skive classes and generally cause mayhem around Hogwarts castle.

George was in the Room of Requirement, which at that moment resembled a large, well equipped Potions Lab. Bottles of strange liquids, cauldrons of bubbling potions releasing coloured miasmas into the room and many glass vials and other equipment were everywhere. It was the perfect setting for the Weasleys' latest series ofWheeze-making experiments, not least because it was one of the places in the castle where they were least likely to be dicovered.

Suddenly the door flew open. George leapt to his feet, looking guilty, then relaxed when he saw that it was only Fred, looking flushed and excited.

'Did you get it?' George asked eagerly.

'Ta da!' said Fred, waving a small jar of black powder. 'With compliments of Professor Severus Snape.'

'Great!' Without further ado the duo set to work. Their mission for this particular lunch break was to develop a way of speeding up time over a small area, so that dull and boring lessons would go by much faster for the student using their product. The black powder was Essence of Mayfly, used in potion making to speed up processes that would usually take too long. Mayflies were perfect for this because of their short, fast lives.

'Ok, any ideas?' asked Fred.

'Well, I hadn't really thought any further than getting hold of the powder, but we'll come up with something.' said George flippantly.

Half an hour later, despite having blasted the powder with all the charms and transfiguring spells they could think of, mixed it with many of the concoctions dotted around the room and even rolled it into balls and bounced it off the walls when they were totally stuck; the twins had as yet failed to extract the time-accelerating ingredient from the Mayfly powder.

'What about the Reducto Curse?' suggested Fred, banging his head rhythmically against the table in a vain attempt to stimulate his brain cells. 'Ow, this actually hurts a lot!'

'Nah, done that. Just made a mess all over the floor.'

'Did we try a separating solution?' asked Fred, supporting his now quite painful head on his hand as he leaned on the tabletop.

'We wanted to, but they're banned, remember? Class C non-tradable substance since You-Know-Who used them for separating people from essentialbody parts when he got annoyed.'

Fred sighed. 'Bloody Hell. We've got to get this one right, think what a seller it would be; every student who takes History of Magic would want it for starters!' he sat for a while, brooding. 'What about a Splintering Hex?' he suggested eventually.

George obligingly grabbed his wand and, pointing it at the small pile of fine black powder, muttered; 'Krakerus!'

Instantly the one pile became many smaller ones, but nothing else changed. Disappointed, Fred waved his own wand and put the Mayfly powder back to how it was.

'I wish this stuff was as easy to work as the Marauder's Map!' said George, frustrated. With less caution than would be advisable with a restricted substance, George poked the little pile of powder with his wand and said despondently; 'I solemnly swear that I am up to no good.'

There was a split second of total silence and then the powder exploded in their faces. The twins' world went black.

A/N: So, what do you think? Sorry if this chapter is a little bit boring, but I have to start somewhere! The next chapter should be more fun as the twins encounter the infamous Marauders. Coming soon to a computer near YOU! Lol, review please!