Book excerpt: Something's wrong with Tasha--she's not herself. At least that's what Amy thinks. And a best friend would know! Tasha's eyes look glazed. Her usual quick comebacks have become dull, one-word answers. It's as if Tasha is acting out some part in a horror movie. Only this isn't a movie, it's real. One by one, Amy notices other personality changes. Everyone seems possessed! And soon . . . whatever is happening to them may happen to Amy too.