This is absolutely fantabulous, Mystery Author! Your Filch voice is so, so amazing, you've fleshed him out into a funny, insightful, still-snarky and multi-layered character. I love all the little details about him - not liking to be touched, his relationship with Pringle and his impressions of Umbridge (who is also absolutely spot on, omg), MR PUMBLECHOOK (seriously omg that is the best cat name in the history of ever). I especially love the way you used language to create his character - the working-class speech and the wonderful use of slang (she had a pair of thrups on her like he wouldn't never of expected, definitely a favourite)
And Snape! Oh, Snape. You paint him so beautifully through Argus' eyes - capturing his realistic body and unattractiveness but also his powerful magnetism. And his attitude and facial expressions and every little thing Filch observes about him - even though we don't get much dialogue from him until near the end, his character comes through beautifully.
I love your McGonagall, too, and everything about her from the glimpses we get of her through Filch's changing attitude, to the arguments and the bare feet on the couch and the pins in her hair. You depict their relationship so beautifully in all those little images.
So much love for this story, omg ♥. Will be reccing this one like whoah.