Serena White and Joey Richards have to stop Andrew Sullivan from creating and releasing his new army of Hosts. Hosts can form into other people's bodies, actually use them, but when they're done, they leave the people dead. This is Andrews way of drawing out Serena becuase he knows what her real story is, he only wants her power. When Serena starts seeing news of dead people, and starts finding them, she takes matters into her own hands. Joey always stays by her side as he is her keeper, he's supposed to protect her and make sure she doesn't over use her powers, but in these deadly situations, he doesn't mind what she does.