On a cold, rainy night in Lancaster County, Pennsylvania, an Amish man named Jacob Stoltzfus drives his horse and buggy along a two-lane road when a car full of kids viciously rams the buggy. When he pulls off the road to inspect the damage, a man in a pickup truck pulls over and demands Jacob give him the bag he is carrying. When the bandana obscuring the man's face slips off, the thief shoots Jacob.

Pennsylvania State Trooper John Lapp, who left the Amish faith fifteen years earlier, is called to the crime scene. He grew up with Jacob Stoltzfus and was once in love with the victim's...