Suzannah Lipscomb investigates the origins of the obsession for mass witch hunts and trials that swept the British Isles during the 17th century. Travelling to Scotland and Denmark, she challenges the accepted wisdom that King James VI of Scotland, later James I of England, was responsible for stirring up the hysteria. She also tells the story of Scotland's first mass witch trial in 1590 and the infamous Pendle witch trials towards the end of his reign.

Suzannah Lipscomb's investigation into the notorious 17th-century witch trials concludes with a profile of Matthew Hopkins, the opportunistic puritan witch-hunter who transformed paranoia about Satanism into a lucrative business as he hanged hundreds of people for crimes they could not possibly have committed. Making use of contemporary reports, Suzannah paints a portrait of a man who believed he could cross any boundary and break any law to achieve his goals. Naming himself `Witchfinder General', Hopkins toured the country charging fees for his services, but Suzannah's research reveals that ultimately, the public's distaste for witches was not as strong as its hatred of being conned by charlatans. Hopkins would eventually die of tuberculosis in relative obscurity, but his malign legacy lived on across the Atlantic, as witch-hunts began in Salem, Massachusetts.