Peter O'Toole by Jeff Vespa/WireImage.com
, a recent Oscar nominee for his work in
, will play Pope Paul III and thus square off against Jonathan Rhys Meyers' Henry VIII in a VII-episode arc on Showtime's
is joining Showtime's
as a series regular this coming season, playing an FBI agent snooping into a string of murders at the hands of Dex, and also serving as a love interest for Dex's loser of a sister.