I don't know what to say. I seriously did a word-count check on this because I couldn't believe you managed to fit every single thing I love about Snape/Filch into so relatively short a story. Little Snape taking refuge in Filch's rooms, Albus thinking the worst, Filch at a brothel (and what a brilliant bit of foreshadowing that was), unexpected Muggle interventions, and Snape surviving DH! You honestly could not have written a more perfect SS/AF story for me.
For once, I am actually...95% certain of my gifter's identity because this is just too good and too apt. *peers suspiciously*
This made me laugh out loud: "Argus," Severus said, standing up and indicating the door. "Are you coming?"
"Near enough," replied Argus with a dirty grin, before picking up the spare bandages and following Severus out into the corridor. "Near enough."
And so did drunk!Severus but I would have to quote that entire section to fully express my glee. That was just adorable.
And this made me coo: "Good lad," he says.
And I have to confess, I was on tenterhooks when Filch entered the Shrieking Shack. I honestly didn't know which way it would go, and then I had a brief thought that it was going to be a pasted-on happy ending. Then we went back to the brothel, and I did a little "genius!" fist-pump.
Thank you so much, Mystery Author. This was the best Christmas gift I could have asked for.