Remus Lupin wakes, and knows immediately that today is not going to be a good day. Indeed, it will be a very bad day. He has been dreading this day for weeks. Why, you ask? Well, it is because it is April First. April Fools Day. And to his marauding best friends, this day is holy.
Remus, known as Moony by those who matter, recalls only too well this time last year. It had all started very early. Five in the morning, to be precise. "The early bird gets to cause mass havoc," is what James had said when met with tired grumbling. Then with no more than a conspiring wink to Sirius, he had turned on his tail and set off for the dungeons. Which, as everyone who had been present at Hogwarts that fine Spring day in 1975 would remember, was where his operation had begun. This was natural, because they were Gryffindors. The Slytherins were the enemy. Especially an unfortunate Slytherin by the name of Severus Snape. Target number one.
James Potter, while undeniably a flamboyantly magical young man, had a certain affinity for troublemaking. And in infiltrating the Slytherin common room using the password Remus had discovered in his endless research, he was demonstrating it. Sneaking up to the Fifth Year dormitories, he quietly whipped out his wand and rolled up his robe sleeves. It took only a few choice words and a flick of the wrist, and Snape's index finger was being carefully manoeuvred into his left nostril. A permanent sticking charm later and James was tucking his wand back into his belt with some satisfaction. One prank down, two to go. Reaching into his bag, he pulled out one small round brown object. Grinning, he stealthily moved over to Snape's trunk, and began stuffing Dungbombs among his ill-fitting garments, one after the other. Then he tucked a few more into the bed sheets and around the pillows for good measure. Merlin bless whoever invented the Self-Exploding Dungbomb. Positively prancing back down to the common room, he planted a few more Dungbombs before opening the portrait to leave. Then with another quick wand movement, he left the Slytherin common room in peace. For the moment. It was a shame he wouldn't be seeing the action, but he could imagine it. Slytherins choking on Snape's stench, trying to escape out of the common room into the hallway, only to discover that the portrait would now only open for one Mssr Wormtail. That was one of his greater pranks, he thinks as he struts back towards the Great Hall.
At the same time, Sirius and Peter had been booby-trapping the castle and its grounds. Well, Sirius was supervising Peter, and Peter was booby-trapping the castle. Remus had been tagging along for a while, but had looked so out of place that Sirius had decided he was a liability, and benevolently sent him back to bed. So while Remus had been huddled under his covers, nervously reading and thinking over and over again that nothing good could come of this day, Sirius and Peter had manned the forts alone. Dr Filibuster's Fireworks were carefully balanced against many a classroom door, poised to go off as soon as the door was opened. That would certainly disrupt the lesson plans, and, if they were very lucky, maybe even set something on fire. They were to discover later that one of the smaller fireworks had flown into a Second Year's ear. They couldn't be happier with that result. Their next port of call was every bathroom facility in the castle. A simple charm as performed by Sirius, and the toilets were set. When the flush button was pressed, water and waste would not retreat down into the plumbing, but would explode in a towering fountain of excrement, unable to be rectified for thirty minutes. A classic, Sirius believes, but with good reason.
The two marauders had also ducked into Moaning Myrtle's bathroom. Sirius, always the charmer, had given a few compliments, shaken his dark, carefully tousled hair, and Moaning Myrtle had been eating out of his hand. Peter had, as so often in his life, felt redundant. Batting her ghostly eyelashes, she had promised that anyone who entered her domain would find themselves unable to turn on any of the taps, and that as soon as they gave up trying, water would gush out and be unable to be turned off. Smirking, both Peter and Sirius left the bathrooms and headed to the Great Hall, the rendezvous point. Along the way, Sirius threw a few charms around, ensuring the suits of armour would threateningly swing their axes and swords when people passed by. And if someone accidentally got in the way of the swing, well, all the better.
The three marauders entered the Great Hall. A few people were already there, innocently enjoying their breakfast. They joined the Gryffindor table and watched with amusement as people began streaming in. Remus, looking a sleep deprived nervous wreck, eventually joined them. Glancing around, Remus could see people drenched, people bruised and clothing torn. He could see many knowing faces turning to James and Sirius. But he couldn't see a single Slytherin. About to ask why, he was interrupted by a small stampede. James was disappointed. Apparently someone had let the Slytherins out. Oh well, he thought, at least I've succeeded in socially isolating Snivellus. And it was true. Slytherins, handkerchiefs over their faces, were glaring at Snape with utmost hatred.
Sirius's small burst of glee was cut short when Professor McGonagall stormed in after the Slytherins. Apparently it was she who had released them from their stinking prison. And… she seemed to be dripping a little more than usual. Remus had a sudden desire to crawl under the table. Instead, being a brave Gryffindor, he just braced himself for what was definitely coming.
"MR POTTER AND MR BLACK?" She screamed with a force never before seen. "A BILLION POINTS FROM GRYFFINDOR!"
Oh no, Remus was not looking forward to today at all.