Panic gripped the community around a small hospital in West-Central, Indiana in the mid-90's when too many patients were dying for reasons no one could explain. Nurses at the hospital were taking bets on how many would die before their next shift. Drawings were created on a ward bulletin board depicting a bus to heaven with the added question, who's getting on the bus today? A sign was placed outside the ICU which sarcastically read, now serving #147. The epidemic forced many others already suspected. A mean-spirited nurse named Orville Lynn Majors had been present for 63 of 67 deaths occurring over a brief 4-month period. Her findings would launch one of the most intensive criminal investigations in Indiana history. It would end with one of the most medically intriguing trials of our time. Northhampton, Massachusetts was being carefully watched by three of her co-workers. None of them wanted to believe that Kristin Gilbert, an experienced nurse and mother of two young boys would intentionally kill her patients. Their suspicions would spark an investigation uncovering some of the most bizarre behavior ever witnessed by investigators. Before it was over, Gilbert's blatant affair with a hospital security guard would lead her to try and also kill her husband. Her need for attention would lead to her purposely creating Code Blue emergencies, setting fires on the ward and calling in bomb threats to the hospital. She would eventually face the death penalty in a controversial and emotionally charged trial. notorious cases of nurses intentionally killing their patients. Mitrione unfolds two of the most extensive and complex criminal investigations to reveal the bizarre behavior and probable motives of both a male and female serial killer. Both investigations and trials would be forced to answer the question of HOW the victims were killed before the WHY could ever be asked.