This past weekend I had the pleasure/displeasure of watch the AMC miniseries 'The Prisoner'. It looked like a good movie and started Ian McKellen, or as I like call him 'Gandalf, and Jim Caviezel. After watching the movie, I was left in a wierd state and torn between loving the film and hating it. I pondered how to pull something like that off in a game.
This movie has lots of twists and depends on the character's http://www.imdb.com/title/tt1043714/PoV to keep the watcher guessing, read furter may ruin the movie for you.
So the basis of the movie is that the main character, named 'six' played by Caviezel, comes to a place in the desert known as 'the village'. All people have numbers and everyone accepts the way things are, and that the village is the only known place in the world. Six, on the otherhand, has flashes of his other life in New York and fights against the overseer of the village 'two', played by McKellen.
The climax comes when six comes to realize that the village is not another place, but a shared subconcious of the group who live in the village. Things are happening in the real world in tandem to what is happening in the village.
I found this to be an interesting concept and along the lines of the Void and the Word books by Terry Brooks, where the main character flashes between the present day and the future when he sleeps in the other world. It stated that when he sleeps, he sees the world as it would be if he fails in his mission. I always got the distinct feeling he was actually in both worlds.
So, I was thinking, how would character's handled a game where their characters were constantly switching between realities, trying to figure out, which one was real. I may experiment with this idea for my game along side with a setting that is similar to Shadowrun. The character's may well think it is the matrix, but come to find it is something fare mor sinister.