This might be the 3rd season of True blood. There is more Shapeshifters in this one.
Vampire Bill is kidnapped in the city of Shreveport while doing secret work for the queen of Louisiana, and Sookie sets out to rescue him with the help of the handsome werewolf Alcide Herveaux. Bill is being held and tortured by his maker, Lorena. With the help of Alcide, Eric the Viking vampire and Bubba Sookie eventually rescues Bill, only to break off their relationship when she understands that Bill has been unfaithful with Lorena (Bill also raped Sookie, which also might have something to do with it).