[ He frowns, both because he doesn't give specific names and because there are potentially others in their group who already know what he's trying to find out. ]

It's not just one more thing. The mirrors only work until they're broken, but we can't break every mirror we come across. [ Or they risk doing what he did. ] ...The fact that they had to spread the word means they might not have realized what they were doing until it was too late.