It's Dr. Kay Scarpetta's birthday, and she's about to head to Miami for a vacation with Benton Wesley, her FBI profiler husband, when she notices seven pennies on a wall behind their Cambridge house. Is this a kids' game? If so, why are all of the coins dated 1981 and so shiny they could be newly minted? Her cellphone rings, and Detective Pete Marino tells her there's been a homicide five minutes away. A high school music teacher has been shot with uncanny precision as he unloaded groceries from his car. No one has heard or seen a thing.