Anna Paquin and Stephen Moyer

True Blood has brought witches, werewolves and vampires to life over the last three seasons, but everything you think you know about the supernatural beings will be upended this season.

"Everything you thought you can count on, you can't," executive producer Alan Ball says. "Vampires are not stronger than certain humans, shapeshifters can do things other than shift and there are ghosts."

Here are 10 things we do know about what's coming up, straight from the cast of True Blood:

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1. It's all about the witches: A band of witches tap into a new form of power, causing Eric (Alexander Skarsgard) to lose his memory. At the head of the coven is Marnie (Fiona Shaw), a vengeful witch coming into her powers and out for revenge. Unfortunately for Lafayette (Nelsan Ellis), he will be dragged into the increasing vampire vs. witch tension. "Lafayette loves his boyfriend, [Jesus, a practicing brujo], so he's trying to deal with [magic] in stride, but it keeps sucking him in and he doesn't know what's going on," Ellis says. "He discovers who he is in the middle of all this stuff."

2. Sookie, independent woman: After discovering that Bill (Stephen Moyer) was working for Queen Sophie-Anne to gain information on her, Sookie is "learning to stand on her own," Anna Paquin says. "At the end of last season, she was at a point where she was willing to walk away from everyone and everything, particularity those troublesome boys. It's not that she doesn't want or need anyone, she just isn't dependant anymore." That's OK for Bill, though. "Bachelorhood kind of turns out all right for Bill," Moyer says. "He's decided to enjoy it while he can."

3. Vampires in trouble: Eric's unfortunate run-in with the witches will send his lieutenant, Pam (Kristin Bauer), into a downward spiral, which is bad timing in the current vampire climate. "The post-Russell Edginton world is hard for Pam," Bauer says. "It's a political environment this year, so she's supposed to be doing what the other vampires are doing — holding babies and shaking hands — but she's incapable. So we see her cause some trouble."

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4. Tara returns as a new woman: After getting out of Dodge in the season finale, Tara (Rutina Wesley) will return to Bon Temps hoping to turn over a new leaf, but will immediately find herself in a mess of trouble. "She gets swept back into the world of vampires so quickly," Rutina says. "She doesn't want it, but she has no choice." Fortunately, there may be hope for her yet. "If there was to be love for Tara, I think she's ready for it because I think she's learned to love herself and has opened up in a way."

5. Shifty shapeshifters: The days of Sam (Sam Trammell) turning into a dog or bird are child's play compared to what he'll do this season. "My character explains the full-range of capabilities that shapeshifters have, and a lot of people that she's talking to at the time don't even know some of that," says Janina Gavankar, who'll be a love interest for Sam this season. "There's a really dark side to shapeshifters as well and that's something we'll explore this year. There's potential wrongdoings that can happen."

6. Jessica, domesticated? Jessica (Deborah Ann Woll) and Hoyt (Jim Parrack) will make a go of living together, but a human and a vampire cohabitating isn't going to be easy. "Jessica is a vampire and I'm not quite sure that domestic life is really what she's in for or what she desires," Woll says. "She's still gotta figure that out because they moved into this very quickly." Helping her navigate this life is Pam, who acts as a "big bad" older sister, says Bauer. "Pam is a very different kind of mentor for Jess than Bill is," Woll adds. "The things you might not want to tell your dad, you may tell your cool aunt."

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7. Jason's growing up: Once the older slacker brother of Sookie, Jason (Ryan Kwanten) has now stepped into a role of responsibility that will get him into even more trouble. "This is the season of the biggest growth for Jason, where the young boy turns into a man," Kwanten says. "He's forced to try and raise a tribe of people and eventually fight for his life."

8. PD's into V: The end of last season teased impending trouble for Andy (Chris Bauer) when it comes to V, otherwise known as vampire blood, an addictive drug that can ruin your life (See: Jason Stakchouse, Debbie Pelt and the rest of the werewolves from Season 3). "It's like old demons, new problems," Bauer says of Season 4 for Andy. "At first V does a lot of good. He had that cast on forever, but after a couple of drops, all of a sudden he's ready to box. He's a guy who we know has issues with substance, and he keeps saying he's done, but he's not done." 

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9. Arlene and Terry tackle parenthood: As if Arlene (Carrie Preston) could ever be the voice of reason, she's especially on edge this season. "I wouldn't be playing Arlene correctly if I wasn't playing her fully, fully stressed out," Preston says. "When you're talking about a child or potential child, and you're talking about it having a father that was a serial killer, in Arlene's mind, she's absolutely justified in freaking out. Luckily, Arlene has found Terry [Todd Lowe], who will put up with all her insecurities." On a possibility related note, Preston adds, "Arlene is going to come face-to-face with something that we haven't even seen on the show yet."

10. Debbie's back, baby: Alcide's psychopathic, V-addicted ex-girlfriend, Debbie Pelt (Brit Morgan), will return this season with a new prerogative. "You're going to get to see a different side of Debbie," Morgan says, adding that Debbie will attempt to make amends with Sookie and find some normalcy. But the werewolf in her isn't gone. "You're going to get to see cool things with some of the wolves that you didn't get to see last season," she says.

What are you most excited for this season?