It's 1612 and a woman is in a courtroom. She's accused of killing three men through witchcraft. She's presented with a confession that she denies, then a girl is brought to testify against her. The girl bursts into tears as the woman screams at her desperately, and the woman is removed back to the dungeon.

Once the girl has her audience she jumps upon to a table and calmly denounces the woman as a witch. She's the woman's own daughter and she's nine years old. Jennet Device was a key witness in a trial that would lead to the execution of 10 people, including all members of her own family. But twenty years later, Jennet herself would come to be standing in the court charged with the same offense.

Jennet, a nine year old beggar, was part of a bigger story - of justicers, clerics, and physicians, even the king himself. Someone who would normally have been lost to history has lived on because of a chilling role in one of the most disturbing witch trials on record.

This is a story about fear, politics, religion, science and magic. But it's also about words and stories and just how powerful they can be. The two trials that shaped the life of this little girl are emblematic of a much bigger story - the transition between a pre-modern world and a supposed age of reason. And yet our fear of evil has never really gone away... neither, some say, has evil itself.

Fear of evil was endemic in England, four hundred years ago, when King James I was on the throne. James was living in fear of Catholic rebellion in the aftermath of the Gunpowder Plot. Recently arrived from Scotland he was on the throne in a strange land and some parts of his new kingdom were particularly troubling.