"It's just another element added to the supernatural craziness of it all," says Anna Paquin, who plays the telepathic Sookie Stackhouse.
"There's no way you can ever get bored on a show like this. When you think you've seen it all and done it all, something weirder and wilder comes out of the woodwork."
Weirder and wilder should provide an infusion of O+ for an avid fan base that more than doubled during True Blood's second season to 5 million US viewers for each episode.
The thirst for Blood may be unquenchable.
Fan site true-blood.net reports more than four times as many visitors over the past month as in the corresponding period in 2009.
Why do fans respond so strongly? "Part of us yearns for the muck of the primal," says series creator and executive producer Alan Ball.
"We still have part of us that feels in awe of nature and all of the stuff that is bigger and scarier than us ...
I think True Blood has evolved into a show that can feed that desire, that incorporates fear, terror, sex and transcendent behavior in a way that's really entertaining and funny at the same time."
And over-the-top bloody, of course.
The series roughly follows the popular Sookie Stackhouse novels of Charlaine Harris, which focus on the mind-reader and her relationships with vampire boyfriend Bill Compton and other folks (human and otherwise) in rural Bon Temps, Louisiana.
The new season, which introduces werewolves, more shape-shifters and the byzantine world of vampire politics, corresponds to the third novel, Club Dead.
"This is classic, escapist fun," says Stephen Moyer, who co-stars as the 173-year-old Bill.
"You can read it on so many levels.
It can be an hour of escapist drama.
You also can watch it for comedy, suspense, as a thriller, as a horror.
It's an audacious show."
When we left them, Bill had disappeared, apparently via kidnapping, after proposing to Sookie; shape-shifter Sam Merlotte (Sam Trammell), owner of the bar where Sookie works, had embarked on a search for his real family; and Sookie's best friend Tara (Rutina Wesley) was grieving over the death of her boyfriend.
Bill's disappearance "is not really the way every romantic dream proposal goes. The girl bursts into tears, runs to the bathroom, comes back to say yes, and the dude is gone," says Paquin.
"That's going to be a pretty major plotline for Sookie."
If there's a theme to this season, it's identity, Ball says.
"Each character is coming to terms with who or what they are.
"We're finding out what makes them tick and what they're willing to do and not willing to do, and what they're willing to fight for and not willing to fight for," he says.
As is apparent, the True Blood world keeps growing, which Ball says partly reflects Harris' novels.
"It's bigger, or at least it feels that way," says Deborah Ann Woll, who plays the coming-of-age vampire Jessica.
"Half the faces around the table reads [of scripts] are new people. I don't know what [their story lines] look like, what their sets look like or what their costumes look like.
"It feels like five TV shows are going on at the same time."
If Blood is fun for viewers, plots drenched with blood and sex seem to make it the same for those in the show.
"The material is endlessly entertaining," Paquin says.
"It's about as much fun as you could expect to have and still technically call it a job."
Moyer enjoys the writing, which keeps the characters off balance.
"We're having to react to what's happening around us, rather than us seeking out the drama.
"The drama is happening to all of our characters.
"It feels very visceral and strong and muscular because of it."
Ball is having a good time, too.
"It is so much fun. If you had told me I would be doing a vampire show with werewolves and would be having more fun than I'd had in my life, I would have said, `You're high'," says Ball, who created Six Feet Under and won a screenwriting Oscar for American Beauty.
For all the wildness, Blood wouldn't work unless it found a way to keep the characters grounded, Ball says.
"We might as well have a sign in the writers' room that says, `It's the emotions, stupid'.
"We try to make sure the characters' emotional lives are what's driving the story. Otherwise, it's set pieces and special effects.
"We have such good actors that they can play the romance, the yearning, the weaknesses, the upsets, the disappointments and the triumphs."
Asked if she would be interested in a season for each of Harris' 10 novels, Paquin said: "I'd do it until they pull the plug.
I don't know how long everyone's going to want to watch us running around biting each other and having all the sex and blood, but I think we'll do this until they tell us we have to stop.
"It's a dream job."
- USA Today
• The third season of True Blood premieres on Sunday at 10.45pm on Prime.
