A/N: Well, this is meant to be an oneshot, but it may be quite long. BEWARE!
Disclaimer: I do not own Harry Potter. Rowling does, so go complain to her if you have a problem with it. I took some quotes from the book, and I don't own those either. Nor do I own Captain Jack Sparrow, or the Black Pearl, or the Kraken. If I did own the Kraken, I would gut it. REVENGE!
Captain Jack Sparrow felt rather ill. Being eaten alive by a giant octopus is not a pleasant experience, and to worsen matters he had consumed an awful lot of rum beforehand. But the hangover and the stench of the Kraken's breath were not the worst things. The worst thing was that Jack was now lingering in what appeared to be a permanent state of darkness. Sometimes he could hear voices and snatches of conversations, but most of the time he was suspended in space. It was frustrating. So, naturally, when Captain Sparrow found himself inside what felt like a closet, he was quite relieved to have a change of scenery. That was until the closet door swung open and a tall boy in black and green robes was thrust at Jack.
"Oi! It's bloody well crowded enough already!" he snapped indignantly just before the door shut. Jack lunged for it and burst out, slamming it behind him and trapping the unfortunate boy inside. Two twins were staring at him. They both looked seventeen, with bright red hair and freckles. They shared a look of mingled surprise before shutting their gaping mouths.
"Who d'you think you are?" the twin on the left demanded, reaching into his robe pocket. Jack bowed and smiled roguishly.
"Captain Jack Sparrow, at your service!" When the pirate straightened, a wand pointing at his face greeted him.
"What're ya going to do, lads, poke me in the eye?" he scoffed, reaching to unsheathe his sword. The twin on the right looked incredulous.
"Blimey, d'you think he's a Muggle?" he asked his brother. The other boy shrugged.
"Dunno. Dressed a bit funny, isn't he?"
"Excuse me," interrupted Jack, "but I am a respectable pirate. I don't know what a 'Muggle' is, but –." He stopped as he saw the twins' faces. They were exchanging looks of purest glee, and Jack had the odd feeling they had just gotten an idea about something.
"Bloody hell!" breathed the twin on the right, "A pirate!"
"Lords of mischief and mayhem! The very best and boldest troublemakers ever to walk the earth!" exclaimed his brother enthusiastically. Wicked grins leapt onto their faces.
"Just in time. Let me introduce myself," the twin on the right said, his tone changing from shocked to polite, "I am Fred Weasley -."
"-- and I'm George –-."
"- marauders and troublemakers extraordinaire," Fred finished with a mock bow. Jack smiled slightly.
"And where am I…?"
"Hogwarts School of Witchcraft and Wizardry -," George replied.
"- currently controlled by the tyrant Umbridge –," added Fred.
"- and sight of our next big prank." The twins glanced at each other nervously, unsure of how to continue.
"Being a pirate, would you be willing to help in our rebellion?" Fred inquired. Jack looked around hopefully for some sign of his normal world, but there was none. He glanced back at the twins and gave a nervous chuckle.
"Aye?" The twins looked like Christmas had come early.
The Weasleys instructed Jack to hide himself in a broom closet next to the tapestry of a wizard attempting to teach trolls ballet. He began to argue as they gently closed the door behind him, but they ignored him. Jack looked around. Unfortunately, there was no rum. The pirate sat and began furiously scrubbing the last of the slime off his hat.
Fifteen minutes later, the twins were back. Each was struggling to carry a large crate of what looked like fireworks. Fred set his down, drew out his wand, and muttered an incantation. A third crate appeared in thin air, hovered for a moment, and then dropped down on top of Fred's.
"You take this," the twin in question panted as he passed the box to Jack. He staggered under the surprising weight of it and clumsily followed Fred and George down to the second floor.
"Explain to me more about this 'Umbridge' character, eh?" Jack asked as he plodded along behind Fred. The twin gave the pirate a look of mingled horror and surprise before explaining all about the Ministry of Magic interfering at Hogwarts, and how horrible Umbridge was, and Dumbledore leaving, and how the twins had decided to do something about it.
" – and so here we are, about to set off about fifty enchanted fireworks," Fred finished at length.
"This is far enough," George sighed as he set down his crate. Fred and Jack both set their boxes down next to George's.
"Now what?" Jack asked when neither boy moved or spoke.
"We need to catch our breath –," Fred explained.
"- because we have to run as soon as we light them," ended George with an apprehensive glance towards his discarded crate. Jack winced slightly at the thought.
"Ready?" Fred asked a second later, raising his wand. George nodded at him. Both made a swift slashing motion with their wands.
"RUN!" George yelled as he set off at a dead run for an old tapestry. Fred followed, with Jack hot on his heels. George disappeared behind the tapestry. Captain Sparrow skidded to a halt and glanced around.
"In here!" Fred hissed at him, lifting a corner of the tapestry to reveal a door. The pirate dashed inside just as a loud BOOM shook the floor. Holding the door partially open so they could all see, the three of them watched as huge fireworks exploded into life and zoomed around.
"WHAT THE DEVIL IS ALL THAT RACKET?" roared a furious voice. Fred yanked Jack away from the door as a stern looking man with a pronounced limp appeared at the top of the staircase.
"Filch!" George whispered. Fred's face lit up.
"Brilliant, he'll be spending hours trying to get rid of them!" A few moments later, a squat, fat woman with a lurid pink cardigan over her black wizard robes hurried to join Filch. A look of shock spread over her toad-like face at the sight of the fireworks. Seemingly unable to speak, she and the janitor stood where they were and stared as a dragon firework swooped around the corridor, much to the terror of a group of students that had come up to see what all the commotion was about. A very large Catherine wheel flew towards the headmistress and Filch, both of whom screamed and dodged out of the way. Several more fireworks escaped out the door at the end of the hall. The Weasley twins collapsed into fits of silent laughter. Jack chanced another peek at the scene. Umbridge tried to stun a rocket, which promptly exploded. Grinning merrily at the sight of such mayhem, the pirate ducked back inside.
"This calls for rum!" he declared. Before the twins could reply (if they could reply at all, they were laughing so hard), the door opened and a tall, skinny boy of around fifteen slid into the narrow room. His emerald eyes swept over Jack for a second.
"Oh…hi," he said uncertainly. Fred came to his senses and introduced the boy as Harry Potter, another avid anti-Umbridge campaigner. After everyone was acquainted, Harry turned to the twins with a broad smile.
"Impressive," he whispered, "Very impressive…you'll put Dr. Filibuster out of business, no problem…"
"Cheers," answered George when he could speak again, "Oh, I hope she tries Vanishing them next…they multiply by ten every time you try…"
A few minutes later, when Umbridge and Filch had left to fight the fireworks, Fred and George took Jack to a place they called "The Room of Requirement". Fred walked past the tapestry of a wizard trying to teach trolls ballet three times, muttering, "I need a place to hide a pirate," repeatedly. Finally, on his fourth pass, a wooden door appeared in the wall.
"Ah, perfect!" he said triumphantly as he pulled open the door. Jack's jaw dropped. He was looking at a comfortable beach house, with a hammock next to a window and walls lined with huge shelves. Each shelf was piled with rum. Bottles of rum were stuffed into the crannies around the room, balanced on top of the bookcases, scattered over the floor, and even stacked into a pyramid right next to the hammock. A little farther in was a second room jam-packed with barrels of rum. Even as they looked, a few more bottles appeared on the floor and next to the windows. Jack was in heaven.
"So this is why the rum's gone!" he gasped when he had regained the power of speech, "It comes here." Fred let out a low whistle.
"Blimey, you've got enough here to set up a pub. You have to bring some for the celebrations tonight."
"Celebrations?" asked Jack distractedly.
"Yeah," George said with a cheerful nod, "I'd expect nothing less than a three hour party. We're school heroes!" He and Fred grinned at each other. Through the open door of the Room of Requirement, screams and loud bangs from the fireworks continued to filter in from the lower floors as the escaped explosives spread through the school.
Later that evening, the twins retrieved a very tipsy Captain Jack Sparrow from his hammock and pulled him to the Gryffindor common room. Sure enough, George's prediction was correct. The three were greeted with cheers as the crowd of happy students ushered them to seats of honor. Fred set about the task of writing down the names of all those who wanted to buy fireworks from the Weasley twins. Meanwhile, the fireworks had made it outside and were careening past the windows. By three in the morning, the throng of people had vanished, leaving the twins sound asleep in their chairs. George was snoring slightly as he lay almost half off his armchair. Fred was clutching an empty bottle of rum and smiling softly in his sleep. Jack was sitting impatiently in a seat by the fire, wishing very much that someone had bothered to take him back to the Room of Requirement so he could have some more to drink.