A superior is dead. A party member is missing. The murderer is running.
Time to regroup!
With one of your own absent at a murder where no-one else is missing and the highest security in the country to keep unwanted people out, you have to find the proper place for blame to fall before an innocent gets the axe. Use anything and everything to achieve your goal, but please don’t blow up the city doing it. This isn’t hafling town.