HUMANS HAVE FOUR MOTIVES FOR MURDER: Passion, Panic, Prejudice, and Greed MACHINES HAVE ONLY ONE: PurposeMeet Shelli, a synthetic investigator that hunts defective and often dangerous machines. In its years of service to Homeland Security, Shelli has never questioned its purpose, never doubted its mission, and never failed in its task.  Until now. Partnered with young analyst Jake August, Shelli finds itself wading into deep political waters after a US senator is brutally murdered, presumably by a synthetic. In their search for answers, Shelli and Jake race across America, from Washington DC's halls of power to the vast, frigid plains of Alaska. But every clue they discover only creates more troubling questions, because what they are hunting is neither human nor machine. It is something far more dangerous ... the next evolution.