Oh, wow, this was such a treat! Thank you so much - I'm afraid I read this a few hours ago but was unable to comment then, so I hope I can do the story justice now.
Firstly, thank you so much for writing such a thoroughly engaging story. It sucked me in right from the assured first sentence, and kept me reading straight through to the end, despite its length. I love the way you set up Severus and Eileen's relationship, prickly and complex, and I kind of enjoyed the tidy way you got Tobias out of the way immediately so we could get on with the good stuff. *g*
I adored both romances. I think your Filch voice is my favourite, but all four main characters are wonderful. I love the parallels you draw between Eileen's past and present lives - and I did enjoy 1) the adroit way that you avoided dealing with Hallowe'en 1981 and 2) the way you tied the ending into PS, with Snape and Filch finally having a bit of respect for one another.
Anyway, I was talking about the romances: I loved the way, as another commenter said, you refused to knock any corners off the characters. I adored Severus's surly courting of Minerva, and was completely charmed by him carrying her off to Vienna. The way you bounced the two relationships off one another was really effective, too.
The linguist in me loves "Hexenstrasse", and it's details like this one, and the very lovely scene between Minerva and Dumbledore, that make the story feel so fully realised for me. One of those stories that really feel as if they live beyond the page.
Thank you so much - this truly was a wonderful story and I absolutely loved it!