30 cult members, of varying levels of sanity and skill. Divided into Guilds for convenience and clarity. Could potentially be used as 30 gang members, depending on your needs.
It is a good sized temple with all the appropriate attendents. Who is in the temple running it?
You come upon a ruined building in the back section of a city park (or other out of the way area of the city). The ruins are fairly overgrown. All that is really standing is a doorway and its frame. If you pass through the opened door, you travel to a different world. If the door closes, there may not be a doorway back to get you back.