I'm glad to see that the idea has a little bit of support behind it. To show my thanks, I'll flesh it out a little bit more for you.

The goal of the game is simply to interpret the story based on the evidence we create as a group. The evidence being the letters and other documents we write together.

However, I fully encourage a degree of contradiction to be present. People make mistakes, remember things differently, and even outright lie all the time. 

As more evidence presents itself, our interpretation of the story changes. The world grows. 

You have an unlimited number of characters at your disposal, but of course there can and will be recurring characters.

Unless otherwise noted, it would be acceptable for multiple players to write for the same character. 

The game will be subtle. The game will be long. I hope that there will be a lot of depth to it. 

Myself included, I would like to have five people to start, although more are welcome. I don't usually shut the doors on my RP's. 

Are there any questions thus far?