How about a scenario dealing with a group of heroes OR villains in such a way that you'd want to take it further.
For example how about we have a novice team of heroes or villains being introduced to their new life with a mentor who assigns them tasks as a final test of their readiness.
You could even set it up so the PCs could run characters on their opposing side so this scenario could easily be run from a heroic perception or villainous perspective so the scenario can be run either way.
You could then have players run it twice or more and even have them take both sides and see how that develops!
Might be a little too much but I thought and try explain that idea!