DISCLAIMER: Not my characters.
He really thought it to be a shame, the old punishments dying. He thought it and rethought it umpteen times an evening, all the while scraping mud and various shades of vomit from the floors from the ungrateful students. They had never once thanked him. Except for one girl, an oddball Ravenclaw who acted like she spent a bit much time breathing the fumes of Mrs. Scower's Mess Remover. He'd done it before; tonight was likely one of those nights. He wished the lightheaded feeling would come with some firewhiskey, rather than daisy-smelling fumes. Alas, however, he unscrewed the cap with unsteady hands and set to the corridor to cleanse the Impervioused blood markings on the wall.
Filch knew the Potter boy, probably the Weasley and the frizzy-haired girl helped, had been the one to petrify his cat. They'd disliked her for exposing their late-night shenanigans. Filch disliked them for being subjected to cleaning the awful mess of mud they, like all others, left behind. Dumbledore, of course, says they were innocent, indubitably, unless it could be proved otherwise with solid evidence.
What more evidence than his own eyes could Filch need?
Climbing ladder frame that was as rickety as his own bones, his own mind, he swept the crystallized cleanser across the first letter of the word "Enemies". No effect. Maybe if he just tried that spell, what was it? Kwikspell sent him a custom course; he'd requested spells to use for cleaning when elbow grease didn't cut it. Where was the damn letter?
Empty pocket.
Stepping down to the floor gingerly, his leg still hurt from an incident involving some beast lingering underneath Hagrid's hut while he was transporting fifth years to detention, he limped toward his office. His closet. Essentially, both were one and the same. Though the room itself was quite large, it was given the appearance of being much smaller due to the presence of so many filing cabinets. The cabinets consumed mounds of Dungbombs, detonated shells or otherwise unused, and Fanged Frisbees. There were objects that were merely obnoxious, nose-biting teacups, and some that could easily have been quite dark. No matter to Filch; he had a non-discriminatory policy regarding what would be heaped behind the metal drawers. Anything from a student he disliked. The identical Weasleys, and another generation's equivalent, Potter and Black. It had been more than ten years since he'd seen either. Too soon, had you asked Filch, for there to be a second Potter without regard for rules. Thinking on it, the Boy Who Lived wasn't only a second mischievous Potter. They had been around for all of his time as caretaker.
Letting himself wheeze loudly, he shuffled to his desk. He tried to quiet himself normally, though now it didn't feel necessary, though he felt Mrs. Norris might come round the corner at any time. It was Mrs. Norris who had worried about the state of his lungs, not a single other. She became nervous if his wheezing because too noisy. He stumbled, knocking a horsewhip, used for beating students in the old days, into various manacles hanging behind his desk and causing them to jingle.
How he'd love to carry it around again, that horsewhip. The fear with which students looked at him, a fear no squid could instill upon even a Muggle born. Mudblood, his mother would say. How disappointed she was. It was Dumbledore's insistence on less offensive language that kept him from using it.
Drawing a key from his left coat pocket, he slipped it into his desk drawer, clicking it open for the Kwikspell letter. He shifted several around to see only the outdated ones. The other one, he supposed. Using his ancient beating cane for support, he moved across the room to a cabinet, yanking it open impatiently. He should've known that he would find not his letter, but the inhabitant of all unused closets and cabinets alike.
It wasn't ridiculous.
Ridikulus.
It's not as if he knew the proper spell, anyway.
A thin, wraithish mass, looking as if it'd fallen from a dustbin, was before him. An endoskeleton wore the particles for protection, thick fur lining two lamps, glowing bright but giving the illusion of people burned out.
"M-Mrs. Norris?" Filch stuttered, extending a gnarled hand to his cat. A scream radiated from Mrs. Norris' ribcage, horror ripping from her insides as if she'd been partly stepped on by Hagrid. The lamps protruded, more so as her flesh was melting away from her, masses of hair falling away from her tail and face.
Upon realizing what he was seeing, the same racking sobs and burning in his lungs returned to him, the way they'd come to him earlier in the evening. Like shocks of lightening, burning away at his vital organs. Abandoning the cane, he stumbled from the room with all the speed he could muster without oxygen. Slamming the door, he considered who could vanquish the boggart with as little humiliation as possible.
This could've been possible, maybe it would've been but for the little man in the bowtie, chuckling and pointing, and generally making a ruckus in the previously silent and echoing walls.
"FILCHIE'S 'FRAID, NOT OF A DEMENTOR, NOR BARON, NOR BAT, BUT OF HIS OWN FLUFFY, SWEET PUSSYCAT!"