"You can't. None of us can control anything but ourselves, Remus. We plan and take precautions, but we all know that even the best plan has to deal with the unforeseeable. You prepare, and hope that you have covered has much as possible," he said softly. "And you haven't lived through this before. None of us have. You said you aren't your other self, and this isn't the same Dark Lord. We aren't reliving history, we're making it once again."
Regulus' hands moved over Remus' body, a soft touch meant to add to his words, to comfort when logic wouldn't help. He wasn't good at this, because he'd never bothered, never had to care about someone else, but now he wanted to say the right thing, to give Remus some peace, and yet he couldn't lie. He was too much of a realist for that.
"We haven't lost anyone yet, but we will, and there's nothing you can do about that, and thinking that we'll save everyone is not realistic. We don't even know if we'll survive. You can't-" He kissed Remus again, sighing. "We do our best, learn from the mistakes and move on. We can't let the failures eat us inside, or we've lost."
He shrugged. "So what? You teach them to recognise normal hexes and curses, but you can't know everything, and you can't know things that he's making up on the stop. You need to know a lot more Dark Arts, before you can even come close to see what he does." He rubbed his face against Remus' hand. "You did what you were supposed to. You told her parents. You can't take responsibility for everyone."