A secret society of who knows what beliefs was almost discovered by unwitting Parisian police the other day. They were that close, but decided to leave, report it formally, and come back with more support. When they returned, all evidence was gone.
What's totally cool about this is that the sect's secret chamber was a bar and movie theatre in an uncharted region of the Catacombs. How cool!
Apparently, there are quite a few who scramble underground through hidden entrances or under cover of darkness, to convene in great caverns beneath the great city. Excellent (think Bill and Ted, not C Montgomery Burns). Reminds me that I need to read the books about Edinburgh and the mole people.