Severus snorted and looked amused. "You'd get an argument from many from my world about whether there was a clear cut right answer to the question of light and dark magic. Mind you, their reasoning would mostly likely boil down to 'because I said so' or 'because it just is' rather than any meaningful or logical reason." He could afford to be amused now rather than irritated because he didn't have to deal with such people as he'd had to before.
"On the other hand, I agree with you," he continued. "Then again, I've lived in a world that is full of shades of grey for years with very little in the way of black and white so that almost goes without saying." He paused. He was aware that Wesley had obviously read the books he was from even though neither of them had openly acknowledged it. However it meant that Wesley would likely understand what he was referencing.
"I had to sit at a table and watch a colleague beg for my help and then be murdered and do nothing. I know how many of the people who are convinced they have all the right answers would react to that but what options did I have? I could have fought for her but all I would have done is sentence both of us to death and there was still too much to be done." He looked down at his half-eaten bowl of soup and scowled. "One life for the greater good."
One more life on his conscience. Charity Burbage hadn't been a bad person. Naive perhaps. A little too trusting certainly. Look at how she'd still believed enough in him to beg him to help her despite all that had happened. She'd been eye-rollingly cheerful and chipper in the staff room but she'd also refused to let his curmudgeonly ways drive her away. How many times had he found a plate of biscuits or cakes on his desk courtesy of Charity and her relentless opinion that he didn't eat enough?
He shook the thought away. It was pointless to dwell on it. There was nothing that could be done to change what had happened. At least she had died quickly and cleanly. It was more than many had received.
"It's the potential for collateral damage if SHIELD are foolish enough to think they can handle everything that concerns me," he said with a grimace. "Taking the Dark Lord as an example since he is one I can speak of with some authority. If he were to arrive here, he would think nothing of slaughtering hundreds, even thousands, in this country if it would get him what he wanted." And depending on when the Dark Lord came from and how quickly he got himself up to speed, Severus himself would be very high on that list of things he wanted and not in a good way.