Hm, I read this last night, and I couldn't form a proper comment so left it for today but am still finding it problematic. Let me put it this way - I started reading your stories quite some time ago, and quite a few of them are on my favorite list, but this one gives off the feel of a real, professional author - it is so well rounded, that I had the feeling I read a book/novel and in a way shows your own progress as one.
The evolution of both the plot and characters had me pinned to my seat and made me read it all in one go, while I suffered with Severus, got highly annoyed with Lily and felt bad for Harry while at the same time admiring the lovely, lovely grey world you have created that simply screams believable and realistic both in plot and in characters. I love flawed Severus because that is what he is - a person whose internal moral struggle has captivated me in the books, as well as here. This is what I want to read as an adult because that is for my mind the real world.
For me the story was more that of Severus and his personal growth, and later his relationship with Harry, and I love you for it.
Anyway, I loved it, it was a genuine pleasure to read so thank you ever so much!