Acorrding to Tvguide here are some Spoilers for Season 4 of True Blood
A band of witches tap into a new form of power, causing Eric (Alexander Skarsgard) to lose his memory.
Marnie (Fiona Shaw) who is head of the coven is a vengeful witch and is out for revenge, which causes Lafayette (Nelsan Ellis) to be dragged into the tension between witches and vampires. "He discovers who he is in the middle of all this stuff."Ellis says.
Pam (Kristin Bauer),will be in a downward spiral, which is bad timing in the current vampire climate.
Tara (Rutina Wesley) will be back in Bon Temps trying to turn over a new leaf but will be pulled back into the vampire drama.
Sam (Sam Trammell) will learn his full capabilities and will learn the dark side of shape shifters.
"Jessica (Deborah Ann Woll) and Hoyt (Jim Parrack) will make a go of living together, but a human and a vampire cohabiting isn't going to be easy".
Jason (Ryan Kwanten) has now stepped into a role of responsibility that will get him into even more trouble. He will fight for his life.
Debbie Pelt (Brit Morgan) will be back this season. She was Alcide's ex girlfriend.