Phineas Nigellus Black loathed students. Bratty, obnoxious, angsty, overly-melodramatic. Always whining about some trivial thing or another. And during his years as Headmaster at Hogwarts, it had become extremely clear that the students also loathed him.
Take Valentine's Day for example. He'd banned any and all Public Displays of Affection, from hand-holding to sneaky little kisses, much to the disgruntlement of the rest of the school. He'd endured a week of smoochy-noises every time he'd strode down the corridors. On the big day itself, he'd come into the Staff Room to find the entire space filled with huge red balloons, each adorned with his face. The prankster had even used a charm to prevent anybody from Vanishing them, and Phineas had spent the next hour popping each balloon by hand.
Not only that, but he'd gone to bed that night to find a rather ugly cherub snoring loudly amongst his sheets!
So, when Phineas banned St. Patrick's Day celebrations the following month, he should have known there'd be consequences. On that fateful Thursday, he was oblivious to the whispers in the Great Hall as he settled down to eat his marmalade on toast. The sly looks from the students went completely unacknowledged as he discussed the day's schedule with Professor Dippet.
"Bertha's leaving party has been finalised for tomorrow," Dippet told him, his long beard draped over his shoulder to save it from crumbs. "I did a collection for her amongst the staff. Must have raised a hundred galleons at least; she'll be ever so pleased." Setting down his knife and fork, Dippet fixed his beard. "It's just in my office. I'll leave it on your desk."
"Very well." Phineas wiped his mouth on a napkin and stood. "I'm pleased you've got that sorted. Now, I have a couple of owls to send, so I'll be in my office if you need me."
"Of course. Oh, and Happy St. Patrick's Day!" Dippet gave him a cheery smile and lifted his goblet. A little bit of pumpkin juice sloshed over the side. Phineas pulled a face.
"Pah. Celebrations are merely causes of distraction." He left the Great Hall without another word, scowling at a few of the more obnoxious teenagers as he swept past.
~~~
Later that day, Phineas climbed the marble staircase, walking the corridors until he reached the large gargoyle that marked the entrance to his office. He was met with a sudden explosion of colour. Green shamrocks plastered the walls and floor around the office entrance, and a huge rainbow arched over the gargoyle's head. Even the gargoyle had been painted dark green, a shamrock garland looped around its stone neck.
As he drew closer, he noticed a hefty-looking moleskin bag sat at the foot of the gargoyle. Frowning, Phineas cast a wary eye about himself. The corridor was deserted, so what could this be? Reaching down, he opened the bag, eyes widening at the gold gleaming back at him. And then he realised. "Those tricksters..." No doubt the Valentine's Day pranksters were back on the loose. "Ha! Did they really think I would fall for this? I know leprechaun gold when I see it." He snatched up the bag, the galleons rattling inside. Then, a slow smile spread as Phineas decided what he was going to do. It was time to show those youngsters he was no fool!
Returning to the Great Hall, Phineas strode in, carrying the moleskin bag. As he passed the Gryffindor table, a couple of seventh-year boys began to laugh. Big-headed Alfred Bright and one of the many Longbottom brothers Phineas couldn't keep a track of, and two of the school's most troublesome students. Phineas made a mental note to keep an eye on their reactions as he reached the Staff Table. Dippet caught his eye, frantically waving him over, but Phineas ignored him. There were more pressing matters to hand. Turning back to the students, he cleared his throat loudly, several times, to get everyone's attention.
"Amusing, was it? To vandalise school property with gaudy St. Patrick's Day decorations? Dehcor which, I may add, is against the rules. And to try and trick me into believing these are real galleons? Do you think I was born yesterday?!"
Professor Dippet came around the table, flustered. "Actually, there's something I need to talk -"
"- This is one of the most pathetic pranks I have ever encountered! Absolutely dismal! As if I'd fall for that!" He scoffed, nose in the air. "Leprechaun gold. Really!"
"But Professor -!"
"One moment, Armando." Phineas dropped the bag at his feet and whipped out his wand. "This is what I think about your funny little prank! Expulso!" The bag exploded, blackened shards of gold falling like rain over the nearest students. They began to scream, running for cover. As chaos ensued, wisps of black smoke coiling in the air, Phineas stood, grinning manically. His eyes darted towards Bright and Longbottom. They looked... triumphant? Confused, Phineas looked at Dippet. Dippet stared back at him.
"I've been trying to tell you. Bertha's collection fund went missing. Somebody took it out of my office this morning." Awkwardly, he rubbed the back of his neck, glancing at the scorch-marked flagstone and the last smouldering remains of the galleons. "And, well... I think that was it."