"Because it’s not fucking fair!" She snaps, yanking her arm from his grasp as her eyes flash with a sudden and brilliant fury. "Because none of this is fair and I wasn’t going to burden you with another life to save, Severus. And I saved you because I needed you to live— needed to know that after everything we had to do, after everything they demanded from us and what we sacrificed, that it was possible for us to live for ourselves."