In the late 15th and 16th centuries, a terrifying illness swept through England with brutal speed - striking healthy people in the morning and leaving them dead by nightfall. It was called the Sweating Sickness, and to this day, no one knows exactly what it was.

In this episode, we investigate the chilling history of this mysterious epidemic that haunted Tudor England. Was it a virus? A toxin? An early form of hantavirus? We explore the symptoms, the panic it caused (even in royal circles) and why it vanished as suddenly as it appeared.