This would be a great time to ask her grandmother about her parents. She really did need to know, now more than ever, was she a pureblood? That was what her parents had always said, but... her mother and grandmother both knew so much about Muggles and how to live just like one.
"Is that so?" She said distractedly. "Yeah..." She focused back on his words. "Sounds like a pattern." A dangerous one. "It's just me, but I honestly don't think this is something for students to solve. I'm sure the Ministry has a task force formed just for the purpose of destroying this disease." Or worse, harnessing it as a weapon.
"It's not safe to play around with diseases." She looked at him. "You should know that, by now. Half the things that happen at this school are solved by dumb luck." And magic, but that was besides the point.