HBO is gearing up for the next season of “True Blood”, their successful vampire series that’s been growing exponentially overt the past few seasons (the last being over-the-top bloody). Deadline reports this morning that the new regular roll went to veteran Irish theater actress and director Fiona Shaw who is probably best known in the U.S. for her role as Aunt Petunia in the Harry Potter movies. On “True Blood”, she will play Marnie, a mousy, timid and secretly self loathing storefront medium and palm reader who is taken over by the spirit of a powerful witch. The character was originally envisioned younger but is being adjusted for Shaw. I love how “True Blood” is pulling a “Dark Shadows” in growing on the horror mythology each season.