As far as I can tell, there are about 2 39 Clues guilds on Gaia. I'm vice captain of one: the Cahill Command Center.
It's as well-rounded as I can get it... so far. I need more donations, but it's mostly role-playing, book/card discussion, and theorizing.
I'm begging you- if you like 39 Clues, please join. And donate. So far, the whole guild's running on empty fumes, and I can't keep funds up forever. I need people to actually do stuff in the guild, and people to moderate.
So check it out here. I'm working SO hard for this.
39 Clues: Cahill Command Center