Here is a blurb from HBO's site:
I'm in! Check out the site here:1934. The Dust Bowl. The last great age of magic. In a time of titanic sandstorms, drought and pestilence - all signs of God's fury and harbingers of the Apocalypse - the final conflict between good and evil is about to begin. The battle will take place in the Heartland of an empire called America. And when it is over, man will forever trade away wonder for reason.
...CARNIVLE follows a traveling carnival as it wends its way across the Dust Bowl, focusing on a mysterious young fugitive with hidden talents who is taken in by the carnival, and on the charismatic, shadowy evangelist who will ultimately cross his path.