When police officer Peggy Whitfield receives a series of social media messages that instruct her to commit murder, she is plunged into a nightmare from which there seems to be no escape. She has no desire to kill anyone, but if she doesn't obey the mysterious messenger, she herself could be killed. Can she solve the mystery behind the messages before anyone is murdered? As she digs deeper, Peggy learns of a computer program named Clean that uses online activity to target those deemed unworthy, and as the ramifications of the program become clear and the bodies pile up, Peggy questions the motives of those closest to her and eventually decides the answer is to fake her own death. But is it a brilliant plan that will thwart Clean? Or has she made it easier for someone to kill her-without facing the consequences? 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?