"Oi, Zabini! Get your head out of your arse and get over here to boost me up!" Fred hissed, struggling with a small box, his wand, and an owl flapping its wings in his face and screeching indignantly at him. "I'm not a freaking spider monkey!"
Blaise Zabini looked up from where he'd been examining the floor with disgust and sighed, rolling his eyes.
"I do not understand exactly why I'm here, Weasley. Care to explain again?" Blaise drawled, now turning his head to inspect his nails as if he could have possibly got something beneath them. He hadn't touched anything since Fred pushed open the door to the Owlery – he had even hovered in the door for twenty minutes or so before Fred had walked out of the door, turned around, and pushed him inside.
"Maybe I'll tell you after you've given me a boost!" Fred shot back, swearing as he nearly fell off the ledge he was perched on precariously. Blaise sighed lazily and sauntered over to help the red-headed Gryffindor up. Fred reached up and stuffed the little box into a certain crevice and tapped it with his wand. When the box glowed purple he nodded in satisfaction and jumped down, not apologising when his foot clipped Blaise on the shoulder.
"Now will you remind me, Weasley?" Blaise said in a bored tone, rubbing his shoulder gently but otherwise looking as if nothing had happened. He may have been a Slytherin and Fred may have been a Gryffindor but he was the kind of Slytherin who preferred to just sit and watch, looking bored, rather than get involved.
"Well, this is blackmail really," Fred replied lightly with a shrug, glancing out of the window. "George snuck into Hogsmeade with Katie and, since we're both supposed to be suspended from Hogsmeade, I said I'd stay here and pretend to be both of us, if needed. As it hasn't been required yet I decided I'd come up here and set up some fun for our new Headmistress but I couldn't do it without help and everyone who I would usually ask is either in Hogsmeade, busy, or nowhere to be found. And I know you won't tell anyone, and I knew you'd help, because otherwise I would happily tell the entire school that you were wetting the bed up until the age of twelve." Fred had just been fishing and felt his insides dance with glee when Blaise glanced up sharply.
"You wouldn't dare," he said, his voice hoarse and low and a hell of a lot less composed than it had been mere minutes ago.
"I'll consider not telling anyone if you help me rig the rest of these up," Fred bargained, holding up one of the small red boxes and shaking it lightly. Blaise seemed to finally notice the bag full of boxes Fred was carrying and he gazed at them suspiciously.
"What are those things?" He snapped, quite happy to be out of the Owlery as he followed Fred down the long spiralling staircase. His face contorted with disgust as he noticed a splat of bird poop on his shoe and he huffed in annoyance as he pulled out his wand and muttered "Scourgify" under his breath.
"Fireworks," Fred said offhandedly. Blaise was suddenly seeing the small boxes in an entirely different light. "More specifically, Weasleys' Wildfire Whiz-bangs. I only have to set off one box for every single box around the castle to go off. Me and George spent ages making them and now we're going to use up our entire stock in one day." Blaise wasn't exactly sure whether Fred was happy or annoyed by this.
"Why're you actually doing this?" Blaise asked curiously. He couldn't help it, his Slytherin side made him naturally nosy. Fred stopped in the middle of the corridor and turned to look at him suspiciously.
"I hope you've remembered the stuff I have over you, Zabini. If you're thinking about running back to your little Inquisitorial Squad mates or telling Umbridge; I'll let every single person in this school - ghosts included - know your deepest secrets. Including the one about you fancying my sister – not something I'm particularly pleased about, by the way. How would that look for a pureblood Slytherin like you, huh? Harbouring a secret crush for a blood traitor, and a Weasley at that?" A sour look passed across Fred's face and Blaise realised he had no idea how the whole blood traitor thing affected Fred and his siblings. They were probably actually proud of it, bloody Gryffindors.
"How did you, err, know?" He asked hesitantly, automatically following Fred as he began to continue down the corridor. "About your sister, I mean."
"George and I have our ways," he replied with a shrug, stopping in front of one of the statues and pulling out several boxes. "Besides, you're not the sneakiest of Slytherins – despite your uptight haughty manner – and we're not blind. What's up with that, by the way? The whole thing about looking like you've smelt something bad wherever you go? 'Course you're nothing compared to Malfoy but still, is it like something required of Slytherins?"
Fred smirked at the look on his face and stuck the boxes behind the statue, casting a quick spell and watching with satisfaction as the little red boxes glowed purple before reverting to their normal colour.
Half an hour later, Blaise was grumpy and carrying the bag that was somehow still half full of boxes and Fred was practically skipping ahead of the trudging Slytherin, looking completely delighted with himself.
"For Salazar's sake, how many more of these bloody fireworks are there to put around? This bag weighs a bloody tonne. I'm currently cursing my pride, and you Weasley, for not being able to take such a low blow. It's bloody lucky no one's seen us doing this together – Merlin knows what that would do for my reputation…" He grumbled to himself as they climbed to the floor that Umbridge's office was on. "Why are you even doing this?" Fred rolled his eyes and skipped backwards so he could look at Blaise. It was a wonder he didn't crash into anything.
"The question you should really be asking is: "Why not?" It would be a shorter answer. But, in short, we're doing it for the sheer fun." He shrugged and they appeared at the end of the corridor where Umbridge's office was located, just as George appeared looking slightly breathless and more than a bit disorderly with his messed up hair, glowing cheeks and swollen lips.
"Someone had fun in Hogsmeade," Fred teased with a suggestive smirk and George waggled his eyebrows before turning to Blaise and surveying him with a superior look.
"You can sod off now, Zabini. Fred's real and only partner in crime has returned – no substitutes are gonna cut it when I'm around. Go on, scoot!" He made a little shoo-ing motion with his hands and then the twins turned their backs to him, giving all their attention to the bag which was now on the floor in front of them.
As Blaise headed down the stairs to the dungeons he heard a faint explosion and gave his head a slight shake as he wondered what it would be like to be the partner of a Weasley twin all the time.