If you can't trust yourself, who can you trust? It all started that night in the woods. Cass Anderson didn't stop to help the woman in the car, and now she's dead. Ever since, silent calls have been plaguing Cass and she's sure someone is watching her. Consumed by guilt, she's also starting to forget things. Whether she took her pills, what her house alarm code is - and if the knife in the kitchen really had blood on it.