This was a really brilliant dystopia you've created. It is always difficult to know how much background to give, and whether it will detract from the main story. You hit it just about right. It was chilling, but I adored the ending, in which Lucius got what was coming to him! I also really enjoyed Regulus' and Sirius' correspondence, and the small, yet significant role Remus played.
Draco shook his head, and a phrase Severus never thought he'd hear came out of his mouth. "Don't worry about me; you have to go get Harry. Hurry!" That was perfect!