Guests walked into the ballroom to see a pyramid of oranges elegantly laid out and glued together on a central table, in much the same way that an ice sculpture or elaborate centerpiece would be. On the other surrounding tables was a large quantity of soda and cups, but nothing else. The pile of oranges was intended to clue the first question. Guests were handed masks at the door, and were requested to remove any headgear they might have had.
About five minutes after the event is supposed to start the doors to Sala were closed, there was a loud knock on the door, and in came the seven special agents. They came in quietly and dispersed themselves evenly throughout the room, with a large mass of people staring at them silently.
The intent was that teams would need to ask questions of the general form "what information can you give me about X" with the proper X for each agent. Just mentioning the correct word wouldn't trigger a proper response.
Teams: What can you tell me about oranges? (rest of team statements omitted)
Woman In Orange: "Oh yeah, I'm a little strange. Orange isn't a color spies usually like to wear; it's too flashy. What's standard is the purple of grapes."
Woman In Purple: "Grapes are particularly wonderful for their scent in wine, though personally I prefer the scent of a rose."
Guy With Rose Pinned to His Lapel: "Roses? With all these thorns, they amount to torture!"
Woman With Wrists Bound, and Abrasions on Her Arms: "I've been tortured many a time. The worst is when they put make you sick by bouncing you on a fulcrum."
Guy Dressed as Archimedes: "If you ask me, the fulcrum of a balanced diet is milk."
Woman With a Cow Hat: "Milk is tasty, though it's pretty gross if you mix it with citric acid."
Guy Dressed as a Chemist: "Citric acid! That stuff you get from oranges that smells like flowers and doesn't go with milk? That's no way to torture a spy! To torture a spy, the answer is definitely hydriodic acid."
At this point teams were handed a sheet of paper with "HYDRIODIC ACID" written on it, and in many cases continued to be confused. It was intended that this should be a clear end of the chain, and that teams should leave with the answer, HYDRIODIC ACID, in hand.
If a spy was asked about something else, he said "I don't know about X", "I can't tell you that", or "Yes", depending upon which answer was appropriate to the question. If asked something that was related to his key word but not quite right, he should look uncomfortable and stammer incoherently.
The fact that the orange spy said "yes" most of the time had the unfortunate consequence that people were told that it was ok to take apart the oranges in the centerpiece. Apparently superglue wasn't a strong enough deterrent. The main problem with this puzzle seemed to be people not phrasing their questions as actual requests for information, rather than as casual statements. This resulted in frustration for a lot of people, and was, admittedly, not really clued. You can think of this puzzle as a social experiment, perhaps. Towards the end we attempted to strongly hint the remaining teams towards the answer, so hopefully no team left this event answer-less.
2006 MIT Mystery Hunt