I have actually run Evil Acts so I'll give you my suggestions.
- The case file is heavy on the non-combat situations - make sure your players are comfortable with or are at least aware of that fact.
- Make sure to spend a considerable amount of time getting the players into their characters. Make sure you ask each player the questions contained in the front of the file, and flesh out the rest of the character's aspects before beginning, instead of using the "come up with it while you play" method. Also, consider not showing the character sheets to the players until they've chosen a character to help them pick a concept first instead of a set of combat abilities.
- Play up the danger of the situation. When I ran it I thought it would be obvious, given the source material, that a publicly visible ritual of this magnitude would be very dangerous if disrupted. My players on the other hand (specifically the bodyguard types) didn't really understand the threat and ended up parotting "I standby on watch." and there is only so many Scene aspects of "Watched by So and So" you can put on a place before it becomes disgustingly boring. It is also possible that I missed a portion of the file that explains what threats are supposed to be present but I remember it being kinda light in that area. Think I would add a threat letter or something more eminent to stir the characters to action.
- Do a lot of planning for the end scene because there are a ton of things going on in it and it may not be obvious what is going on, and bulk up the end baddy - she went down super fast with my crew, but again might have been my inexperience...
- Come up with a list of motive and/or goals for each of the major NPC's in the scene, and make sure that most of them involve one or two of the PC's so that when the social parts of the game are starting you can initiate and know why the NPC would be talking to the characters. I felt like all the NPC's were focused on Prospero and basically had no real reason (outside of "we're in this play together") to interact with the player characters. Looking back, I could have had any number of things come up - like the fey playing tricks or trying to get promises from characters, or the chorus putting their plots or plans into place to humiliate the muse character or something. This would help move things along if your players aren't "jet setters"
I guess my biggest issue with the whole case file was that it seemed a bit thin in the "motivate the players" department. It seemed like a great scenario on paper, but when you put players in a scene were they have to care about some in game event that they are supposed to make happen it sorta fell apart.
In the other case file, Neutral Grounds, the character's are immediately put into a dangerous situation, and probably shot at so they get a sense of investment right off the bat.
Evil Acts on the other hand, talks a lot about a semi-mundane activity (setting up for a play) that becomes exciting later, and unless your players are more into the non-combat/exploration aspects of the game, it can drag.
Then again, my players are all of a D&D mindset where they just want RP to be present to introduce combat - so you're mileage may vary. But I would imagine that even in a non-D&D oriented group the amount of "self-investment" that the scenario requires would be troublesome.
Good luck!
