Ronald Weasley looked dubiously into his cauldron. His Fiesta potion had turned an interesting shade of- something. And it was popping. "Should it be making that sound?" he wondered. Hermione Granger looked at him sharply.
"What sound?" she asked him, sounding irritated. She leaned over to his table and heard the odd noises. "Yes Ron, those are its happy noises," she told him sarcastically, then yelled, "NO IT SHOULDN'T BE MAKING THAT SOUND!!!"
Professor Snape glided over to the two. "Miss Granger, before I take the points I surely should, would you care to enlighten us as to the cause of your outburst?" His voice was dryly sarcastic. Hermione just pointed to the flashing concoction in Ron's cauldron, then had the unenviable experience of seeing the professor's pale face go pure white. "Move!" he snapped, pushing her away. Before he or Ron could react further, the strange sounds emanating from the potion crested, and the goo exploded, showering over the two men.
When the room had gone silent again, Hermione peeked over the tall table. The two men were slowly getting to their feet. Both had pained, almost frantic expressions on their faces. She wondered why, as neither had sprouted any new appendages nor were they spitting fire or turning colors. There seemed to be nothing wrong with them, from her point of view.
Snape managed to snap out, "Twenty points from Gryffindor, for sheer incompetence! Clean up, all of you, and get out!" before he turned with a swirl of robes and went to rustle through his desk. As Hermione and Harry helped their friend out the door, they saw Snape pull a thick book from his bottom drawer.
"So what happened?" Harry asked. Ron's freckles looked like they were about to fall off his face, if his eyes didn't pop out first.
"Where's that awful music coming from?" Ron muttered frantically, looking around as if there was a demented DJ hiding around the next corner.
Harry and Hermione exchanged confused glances. They didn't hear anything. "What music, Ron?" Harry asked.
"That- that- can men sing that high? Aaagh! What's with the lights!?!"
The H pair shared another look, before grabbing one arm each and hauling Ron to the hospital wing. Once he was under Madame Pomfrey's confused but capable care [ooh, alliteration] they sat in the waiting room to discuss possibilities.
"Ok, Herm, you always know all this stuff. What's the Fiesta potion supposed to do? I mean, I know it has something to do with parties, but how does it work?"
Hermione thought for a minute. "Well, depending on the exact combination of ingredients added in the last stage, it's basically intended to set the mood. If you don't want to hire a band, for example, you'd make a Sonus variation and sprinkle a few drops in each corner of every room you wanted affected, and it would play music by theme. Or you could make an Amore variation and it would conjure images of candlelight and soft violins or something. Some people have experimented with drinking the potion, to have the effects only for themselves, like, if you wanted a romantic setting but were in the middle of a subway or something."
"So maybe Ron's experiencing symptoms like if he had drunk it," Harry hesitated. "He was talking about music and lights. But it didn't really sound like a fun experience, I mean, he was practically screaming in pain!"
Before Hermione could formulate an answer the door to the hospital wing swung open, and Ron stepped out. In answer to his friends' questions he just muttered something about needing to find an antidote to the potion and asking Snape.