At the conclusion of Season 3, vampire king Russell Edgington was buried alive in a pit of concrete, apparently ending his plans for world domination.
But what happened to Sookie, who disappeared into a flash of light? Will Bill be able to make things right after breaking Sookie's heart? And what awaits Eric, who nearly joined Russell in limbo?
As the season begins, Sookie journeys away from Bon Temps; Eric and Bill try to win back the human public; Jason learns that no good deed goes unpunished; Tara finds refuge in close quarters; Sam bonds with his own; Hoyt and Jessica debate the dinner menu; Jesus urges Lafayette to join a coven; and Terry tries to alleviate Arlene's fears about the baby.
The series follows the on-and-off romance between waitress and part-faerie Sookie Stackhouse (Anna Paquin), who can hear people's thoughts, and 173-year-old vampire Bill Compton (Stephen Moyer).
Other returning cast regulars this season include Ryan Kwanten as Sookie's trouble-prone brother Jason Stackhouse; Rutina Wesley as her best friend Tara Thornton; Sam Trammell as Sookie's shape-shifting boss Sam Merlotte; Nelsan Ellis as Tara's sharp-tongued cousin Lafayette Reynolds; and Chris Bauer as detective Andy Bellefleur.
They are joined by Carrie Preston as Arlene Fowler, a Merlotte's waitress; Todd Lowe as Andy's cousin Terry Bellefleur; Jim Parrack as Jason's friend Hoyt Fortenberry; Alexander Skarsgård as vampire sheriff Eric Northman; Deborah Ann Woll as teen vamp Jessica Hamby; and Kristin Bauer van Straten as Eric's vampire sidekick Pam.
There's also Marshall Allman as Sam's brother Tommy Mickens; Joe Manganiello as werewolf Alcide; Lauren Bowles as Holly, a Merlotte's waitress; Kevin Alejandro as Lafayette's boyfriend Jesus; and Jessica Tuck as vampire spokesperson Nan Flanagan.
Other returning cast members include Evan Rachel Wood as Sophie-Anne, the Vampire Queen of Louisiana; Lindsay Pulsipher as Crystal, a werepanther with ties to Jason; Dale Raoul as Maxine Fortenberry, Hoyt's mother; and Adina Porter as Lettie Mae Thornton, Tara's mother.
New cast regulars in Season 4 include Janina Gavankar as Luna, a shape-shifter who catches Sam's eye, and Fiona Shaw as Marnie, a witch whose agenda threatens the vampire establishment.
Other new cast members include Courtney Ford as lawyer Portia Bellefleur, Andy's sister; Vedette Lim as Tara's new friend Naomi; Alexandra Breckenridge as Katerina, one of Marnie's followers; and Gary Cole as Earl Stackhouse.
True Blood was created by Alan Ball and is based on the Sookie Stackhouse novels by Charlaine Harris. The executive producers are Alan Ball and Gregg Fienberg; co-executive producers are Brian Buckner, Mark Hudis, Raelle Tucker, Nancy Oliver and Alexander Woo; and the associate producer is Christina Jokanovich.