It's such a pleasure to read a long story that's so well-written. There were so many places where I just marveled at your style and your ability to write great IC dialogue for all of your characters. And it was plotty and the sex was mmmmmm and you left the structure of canon intact, but crucially changed its content. And I noticed that your timeline swung at times, but I was never confused because you did that so well. I really do like stories that aren't told chronologically; it gave yours an extra measure of tension and depth.
One part of your diversion from canon that I really liked was that Harry and Snape knowing about each other's roles made both of them feel so, well, less alone. When Snape died in canon, I thought that was one of the saddest parts: that he'd played his part so well and then suffered the horrible consequence of living out the rest of his days with everyone thinking him a murderer. No one knew, and that had to be the worst sort of loneliness. But you gave him, and Harry, at least the solace of knowing that one other person understood their hidden roles. And you really made me think about some other directions...intriguing ones...that JKR might've taken but didn't, chiefly the idea of it being best for Harry to return to Hogwarts for seventh year, where Snape could keep an eye on him, and help him.
You worked the chess scenes so well, and it was so spot on, because this entire war-to-war in the WW was one huge chess game, I think. I'd quote my favorite chess line, but I don't want to spoil anyone, but I especially like where Harry calls Snape the rook, the queenside castle, and Severus' whispered response put a lump in my throat. And the scene between Lucius and Snape in the office, where Snape show's him the chessboard move--that was intensely satisfying! And oh, working in Narcissa seeing the signet ring was genius! I felt vicarious gratification for Snape when Harry told him what she'd said.
Always like to point our at least one line I especially loved; you had so many that it was hard, but here you go:
The only occasion one could class as remotely romantic was when I said ‘bless you’ to your sneeze!” Heeeee!
I did guess what Snape was up to, but it didn't affect my enjoyment of the fic in the least. This is a wonderful wartime story; I was so pulled along that I can't believe two hours have gone by. So, my Snitch, you've nailed your genre and prompts, and given me a story that's already been saved to my 'to reread' file. Congrats, my friend!