Oooooh, I LIKE this! :D Argus' voice here is fantastic, and I love his view of Severus and all the little observations he makes about his character. Young Severus slouching and grumbling and refusing to go to the hospital wing because he can take care of himself, thank you very much. And Argus still thinking of thirty-year-old Severus as a "lad," because, really, the grumbling and bitching and stubbornness haven't really changed all that much, have they?
So many great lines in here. I cracked up over these:
Bad enough that young Severus had taken to slouching in most weekend afternoons, grumbling about one thing or another ("one thing" generally having the name of "Potter" and "another" mostly going by the name of "Black") until Argus sent him off to clean the dungeon staircases, guessing rightly that he'd soon tire himself out of his bad temper.
She'd just assigned him childminding duty, without giving a single thought to how an old Squib caretaker was going to keep all those trouble-making brats in one place without a wand or a sackful of Muggle sedatives
Hee, I love that Argus was the one to save Severus' life -- through purely non-magical means! And these two really are oddly equipped to understand each other, aren't they?