It's a sunny morning in Cambridge, Massachusetts, and also Dr. Kay Scarpetta's birthday. 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 home. Is this a kids' game? And if so, why are all of the coins dated 1981 and so shiny they could be newly minted?

Her cell phone rings, and Detective Pete Marino tells her there's been a homicide five minutes away. A high school teacher was shot with uncanny precision as he unloaded groceries from his car. Yet no one heard or saw a thing.

Looking for more clues that only she can discover and analyse, Scarpetta embarks on the unsettling pursuit of a serial sniper who leaves no incriminating evidence except tiny fragments of copper...