The greatest mysteries all have a shadowy figure at the center-someone who sets things in motion and holds the key to how the rest of the story unfolds.
In epidemiology, this central character is known as Patient Zero-the case at the heart of an outbreak.
This hour, Radiolab hunts for Patient Zeroes from all over the map-from the origins of a blues legend, to the history of the high five, to a race to halt the spread of a deadly disease.