First of all, I need to ask if there is some sort of storyline you guys have made up. If you are interested one I can give a few suggestions:
1) Many people gather to create a faction called "The Heretics" or something who would try to take over Castem. Guards and citizens would have to fight over the possession of the city, and even the Royalty could get involved.
2) Guards vs Robbers. Basically, robbers would act like Robin Hood, only they would keep the money for themselves. The guards would be trying to stop these illegal manifestations of the robbers. Maybe some bounty hunting could take place there too!
OK, I know these are far-fetched ideas, and I don't think they could be feasible. It is just that I would love some storyline to take place or even sole events! That would be interesting:)!