I've had this plot idea in my head for a while where the players have to meditate the negotiations between two related industrial groups (ie miners vs blacksmiths). For both groups I would have, in secret, a list of demands that that group considers non-negotiable, their much more extreme initial set of demands, things that they would never concede to the other side, etc and it would be up to the players to interview and gain the trust of the leaders of both sides to learn what those things are in order to craft an agreement that both sides will accept. It should take place over a bunch of in-game time and involve the players having to balance their own integrity versus their need to win the trust of the leaders, ie one side asks them to wiretap their conversations with the other and other sketchy dealings like that.