When police officer Peggy Whitfield receives a series of social media messages instructing her to commit murder, she is plunged into a nightmare from which there seems to be no escape. If she doesn't obey the mysterious messenger, she herself could be killed. But if she does as she's told, she'll kill her estranged brother. As the bodies pile up, Peggy will have to look closely at her past relationships and work with her kind-of-honest, kind-of-boyfriend in the FBI. But can they contain CLEAN before no one is safe?

Today's headlines are dominated by addictive iPhones, computers taking over our homes and finances, the invasion of privacy, and shadowy figures influencing our every move from afar. Clean tackles head-on one of current society's biggest fears: what happens when we use a computer to make decisions, and the computer starts making decisions by itself?