Yeah...this marquis is an idiot who's outright doing villainous laughter now. I mean, we knew that already, but he's so blinded by greed and hunger for power that the simple stuff like "children you abuse and don't treat like your children won't be loyal to you" doesn't click for him.
At this point, I'm half-wondering if Leslie can cause the downfall of the family even without the duchess. I mean, adoption path best path, but still.
Speaking of which, just what was the plan as far as "contacting" her goes? Because getting a message out of the home seems pretty hard, even if you weren't worried about arousing suspicion.