And the kicker of being the most treasonous as well.
Simply put, this book outlines every secret society for Paranoia XP, each one is given 3-5 pages.
Besides those pearls, there's a complete adventure in the back and a section on why and how the Secret Societies exist. Now that the corebooks have gone through the entire color spectrum once, I can safely say that if you have the core book and don't have any supplements yet, your best bet is to get either this for explanation on Secret Societies, or Flashbacks for some great adventures in all their hardbound glory.