DATELINE MONDAY SNEAK PEEK: The Prussian Blue Mystery01:52
When a San Diego woman arrives at an emergency room, she is near death. Her hair is falling out and her vital signs are fading, even though there are no signs of an infection or injury. Doctors, the FBI and local law enforcement are then called in to try to solve not only a medical mystery, but also a horrific crime. Natalie Morales reports tonight at 10/9c on NBC.