Trail of the Brotherhood is a card driven board game by the creator of Arkham Horror, Richard Launius. In fact, it was dreamed up by Mr Launius over 15 years ago, and has only seen the light of day in the form of three extant prototypes. In the game, one person plays the forces of chaos and the others try to stop him.
Every time he tries to get it to print, strange men with yellow eyes visit his house and draw unearthly circles on his front door.
Now Eos Press actually plans to put it into print, I expect that this is the last we will ever hear from Mr Launius.