I've been obsessively watching the new HBO series True Detective--one of the greatest things I've ever seen. Millions of others are doing the same thing, and maybe you're one of them. It's a crime mini-series set in the bayou country of Louisiana and has something of the feel of my 1991 novel Final Heat, which is long out of print but findable at used-book sites online.
True Detective has thousands of clues, some of them visual, and one of them is a spiral sign possibly aligned with devil worship. Here it is on the back of a victim:
I was looking at it when I glanced down at the coffee cup on my desk and nearly jumped out of my skin:
There are clues everywhere if you look. And the solution may be right under your nose.