"Find out if he's ever done anything illegal. We could blackmail him, or show my father how worthless he really is. Or perhaps he's got the wrong kind of friends. He's probably been a lot of women before. That sort breeds like cockroaches. If we could show that, that should help my sister see sense. Find out about his family. Perhaps he has a sister that we could get into some trouble in return for messing with our girls. Has his family been involved in anything criminal or illegal that we could use against them? Who are their friends? Who are their enemies. Anything we can use against him." He hoped Harry was smart enough for this.