This is a stunning fic. Each day I read the Beholder entries and think, "it will be hard for any future stories to equal this" -- and then they do. I must confess that I would never have thought of linking Filius and Severus, but like all fine writers, you make the pairing seem so right and inevitable that I now wonder why it doesn't have a huge following. The back-and-forth flashbacks work so well, and everything is perfectly in canon. (I love when complex, full stories fit exactly into the cracks of canon, even down to small details like MM fetching FF on the night of Albus's death.)
Perhaps most of all, I'm wowed by the characterization of Flitwick: the opening scene in particular, with fine character-revealing lines like this one: If he was going to do this, he was going to do it well, and that was going to require keeping calm and taking one step at a time. He's such a full, complete person -- all the details of his every-day charms, the way he's adapted his world to his height, the sheer basic decency of him. I love this man. AND he's perfectly canon-consistent (yet never the joke he's sometimes turned into there).
So many nice lines and touches; here are just a few I liked:
SS's ghostly pug nose (ha!) Snarky!Severus: I'm fond of the grand gesture I see how these are topics that require midnight analysis Filius so kindly and cheerfully never giving in to Snarky!Sev casting a water-repelling charm on the skin whilst soaking in the bath struck him as faintly ridiculous then spun on his heel and billowed out of the room "billowed" is used so perfectly here
Every post I make seems more gushing than the last, but I can't help myself: there are superb stories in this fest, and this is definitely one of them.