As I've already told you, I absolutely love the first few sections. The third one, where Severus kills Black while Lucius watches...that gave me chills. It's so heartwrenching.
I think this line is my favorite, though.
Severus’ expression shuttered. “Then that was the difference between you and I, Lucius. It was always about you.”
And then, of course, such a beautiful, sweet ending. Wonderful job, love.